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Best Practice Guide – Visual Simulations has been developed by the Malta Environment and Planning Authority (MEPA) in collaboration with Perit Joseph A Pace. Working Group Lead Author: Perit Joseph A Pace Perit Frans Mallia Published by: The Malta Environment and Planning Authority P.O. Box 200 Marsa MRS 1000 Malta Tel: (+356) 2290 0000 Fax: (+356) 2290 2295 Email: enquiries@mepa.org.mt Website: http://www.mepa.org.mt
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Contents
Page
1
Introduction
4
2
Executive Summary
5
3
Zone of Theoretical Visibility Maps
8
4
Viewpoints
19
5
Photography
26
6
Preparation and Presentation of Visualisations
29
Annexes
Page
A
40
B
Checklist: Zone of Theoretical Visibility Maps, Panoramas and Single Frame Images Checklist: Panoramas and Single Frame Images only
41
C
Checklist: Single Frame Images only
42
D
Glossary of key terms
43
E
Taking good photographs
46
F
A3 single frame transparencies
48
G
Verification of panoramas and 75mm single frame images
50
H
Level of detail
51
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1. Introduction 1.1.
The Malta Environment and Planning Authority (MEPA) acknowledges that the whole planning process will gain from formulating a set of guidelines to promote best practice standards on the preparation, presentation and use of visual simulations of buildings and other structures such as communication masts and antennae, road and bridge infrastructure, ports and other structures which will have a visual effect on the surroundings.
1.2.
MEPA is continuously updating its dataset in the form of aerial photographs and digital terrain and surface models which can be used by professionals in the preparation of visual simulations. These tools, together with the availability of high‐end CAD, GIS and image‐editing software ensures that visual simulations can accurately portray in a realistic manner a proposed change or modification in the landscape.
1.3.
Experience gained by MEPA and extensive research carried out by a number of Universities and professionals has led to a better understanding of how visual simulations of proposed developments are perceived and presented.
1.4.
The main aim of these guidelines is to standardise the way visualisations which are requested during the assessment of planning applications are prepared, presented and used. This will ensure that the visualisations are clearly and easily understood, that they are accessible to the public and that they could be relied upon by all those involved in the planning process to inform their judgement.
1.5.
The methodologies advocated in these guidelines are based on a combination of land‐based surveying, LIDAR data, on‐site photography and the production of accurate computer‐generated three dimensional (3D) models. Other methods of visualisation such as hand‐drawn sketches, computer animation, video montage and physical models are not covered in these guidelines.
1.6.
It is essential that visualisations are technically accurate and credible. Visualisations are essential tools to represent a proposed change or addition to a landscape. They form any integral part of the design and planning application process thereby improving communication between all stakeholders within the planning process and improving decision making.
1.7.
Visual representation cannot replicate the experience of seeing the finished project on site. Moreover, if the data from which the visualisations are constructed is inaccurate, the end result will not be a faithful representation of the proposed modification in the viewed landscape. However with these limitations in mind, they shall remain an effective and useful assessment and communication tool.
1.8.
This document is aimed at architects and urban designers, planners, case officers, decision makers, consultees and those involved in producing visual simulations.
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2. Executive Summary General 2.1.
All applications which require an Environmental Planning Statement (EPS) and Environmental Impact Statement (EIS) shall conform to the requirements set out in this document. Annex A: Checklist: Zone of Theoretical Visibility Maps, Panoramas and Single Frame Images lists the maps and images which together with the methodology statement shall be presented for these types of applications.
2.2.
All applications which do not qualify for an EPS or an EIS but for which a visualisation study will be requested shall conform to the requirements set out in this document. However a proportionate approach depending on the size and context of the proposed development shall be made with respect to: Whether a Zone of Theoretical Visibility (ZTV) map is required, The number of viewpoints, The level of detail (LOD) (Annex H: Level of detail) of the 3D model of the proposed intervention, and Whether single frame images only as opposed to panoramas and single frame images will suffice. It is up to MEPA to determine the most appropriate approach for the proposed project and site in question. It is important that this approach is established and defined at pre‐submission stage.
2.3.
All images for all applications shall be presented on A3 pages in order to ensure that these are more accessible to a wider audience.
2.4.
Due to an increase of major projects in certain areas, MEPA may request the study of cumulative visual impacts. These types of studies shall be undertaken when an EPS or EIS is being requested.
2.5.
For projects which require an EPS or an EIS, a set of photographs of the completed project taken from the same viewpoint locations and under the same photographic conditions shall be submitted together with the compliance certificate to MEPA.
Zone of Theoretical Visibility maps 2.6.
ZTV maps shall be used to determine those areas from where there is the possibility that the proposed development is visible.
2.7.
ZTV maps shall be based on bare ground lines of sight information – screening effects from vegetation or structures in the study area are not taken into account in the ZTV analysis.
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2.8.
A suitable grid or contour interval shall be used to produce the ZTV map.
Viewpoints 2.9.
Viewpoints must be carefully selected with respect to their representativeness and their significance.
2.10. Specific viewpoints to and from particular buildings or landscapes shall be considered in specific circumstances. 2.11. The number of viewpoints will depend on the scale and context of the proposed project and the number of locations required to provide a representative range of views. 2.12. A summary of viewpoints shall be presented on a single drawing. Each viewpoint together with the relevant data shall also be presented individually on a separate drawing.
Photography 2.13. Photography for use and presentation in visual simulations requires the use of appropriate photographic equipment and knowledge of technical skills in the field of photography. 2.14. MEPA places considerable importance on high quality professional photography. This guideline advocates the use of a high quality digital SLR camera with a full frame sensor and a 50mm fixed focal length camera lens. The use of a 28mm fixed focal length camera lens shall only be permitted in very particular circumstances. 2.15. When panorama views are used, these shall be made of individual photographs stitched together with the appropriate software.
Preparation and presentation of visualisations 2.16. Visualisations should be capable of being reproduced and printed such that all parties involved can clearly understand the scale and nature of the proposed intervention. 2.17. Visualisations depict a two dimensional view of a specific location from a particular viewpoint as seen through the camera not as the three dimensional image as seen on location with the human eye. 2.18. Notwithstanding the differences between what one actually experiences on site to what is represented by a two dimensional image, visual simulations are very useful tools to assist in the assessment and decision making process.
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2.19. Visual simulations need to be prepared and presented in a way to allow the verification of the images. This is possible by checking the original image data and a template to check that the image dimensions are correct. 2.20. Visualisations shall include all the relevant viewpoint information, camera and photographic data, reading distance and all other information used in the preparation of the visualisations. 2.21. Depending on the type of application being assessed, the applicant will be requested to submit either a combination of panoramic photomontages and single frame photomontages or else only single frame photomontages. 2.22. Panoramic images showing the proposed development in its wider landscape context are required for professional assessment whereas 75mm single frame images are required for visual impact assessment for a wider audience. 75mm single frame images, in contrast to panoramic images, provide a realistic impression of scale and distance. 2.23. The horizontal field of view of panoramas shall be 65.5 degrees and the vertical field of view shall be 27 degrees presented as an image size of 385mm wide by 144mm high. The panoramas shall consist of 50mm focal length images stitched together in planar projection using software. 2.24. The horizontal field of view of 75mm single frame images shall be that of a 75mm focal length recalibrated from the 50mm image. All 75mm single frame images shall be produced to a standard image size of 390mm wide by 260mm high. In order to convey a realistic impression of scale and distance, the printed image shall be viewed at a comfortable arm’s length. 2.25. All 50mm and 28mm single frame images shall be produced to a standard image size of 390mm wide by 260mm high.
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3. Zone of Theoretical Visibility Maps 3.1.
ZTV refers to those areas from where the proposed development is in theory visible. They help to inform the selection of the study area in which impacts will be considered in more detail and are a useful guide to the selection of possible viewpoints.
3.2.
Generally ZTV maps are based on bare earth analysis as if the ground was devoid of vegetation or structures in the landscape and therefore the ZTV represents the worst‐case scenario. When detailed datasets of vegetation and urban areas are available and incorporated in the analysis, the ZTV map is more accurate in that it allows for screening to be taken into account.
3.3.
The analysis for producing a ZTV map can be carried out over a large area, sometimes even using a 10km or more radius.
3.4.
There are various ways how ZTV maps are produced; some ZTV maps take into account the effect that distance has on the visual impact of the proposed development by calculating the vertical or horizontal subtended angle at the eye from a grid of receptor locations. These types of ZTV maps may be presented in the form of colour height bands superimposed on a large‐scale map or raster image with the colour bands representing the amount of impact based on the height or width of the proposed building, its distance from the visual receptor and the terrain.
3.5.
Other ZTV maps begin their analysis at the object that one wants to determine the visual envelope for and looks out from that position; these are sometimes called ZTV line of sight maps. Another type of ZTV map, sometimes referred to ZTV line of sight to features is a binary ZTV analysis which tells you whether or not a proposed development is visible from a grid of receptors.
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Figure 1: Malta 2012 ortho grid map
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Figure 2: Gozo 2012 ortho grid map
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Figure 3: An example showing a rectangular building, approximately 25 metres high superimposed on 10 metre interval contours and on the Malta ortho grid map
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Figure 4: The ZTV based on the building surface. The legend shows the vertical subtended angle from a grid of receptors
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Figure 5: The ZTV based on the line of sight to features is a binary ZTV analysis which indicates whether the building is visible (in whole or in part) from a grid of receptors
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Figure 6: The ZTV based on the line of sight begins the analysis at the object for which the visual envelopment needs to be determined and then looks out from that position
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Figure 7: Another example showing 11 pylons, 40 metre high superimposed on 10 metre interval contours and on the Malta ortho grid map
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Figure 8: The ZTV based on Visibility to Point feature. The legend shows the number of pylons visible from a particular location
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ZTV preparation 3.6.
Data can be obtained from a number of sources, such as detailed survey data, LIDAR data, ASCII data which is gridded data (square grid DTM) at particular grid spacing, and contours. It is common practice to construct the ZTV either from DTM since this enables the data to be simplified with ease by increasing the grid spacing from say 1m to 5m, 10m or more, depending on the study area required, or from contour data which is usually the data used for constructing a Triangular Irregular Network (TIN) surface.
3.7.
Although it may be necessary to increase the grid spacing of the DTM, minor topographic features such as rock outcrops and road cuttings may be lost when interpolation is carried out.
3.8.
In order to construct the ZTV, the proposed intervention needs to be accurately represented. However a simplified block model at LOD1 suffices to produce an accurate ZTV analysis.
3.9.
In order to compensate for potential inaccuracies in the terrain data, the viewpoint height used in ZTV analysis shall be 2 metres.
3.10. When the area of study of the ZTV exceeds 10km, the effect of earth curvature needs to be included in the ZTV calculation. 3.11. Although in general ZTV maps are based on bare earth analysis, it is allowed to take into account surface screening such as vegetation and buildings. This type of analysis can be carried out by using LIDAR data, or alternatively by manually applying thicknesses to different areas of the DTM. Since this type of analysis tends to be very expensive, this should be only reserved to very particular cases. For most projects, bare earth analysis provides enough information to understand the pattern of visibility. 3.12. If the analysis of a ZTV is carried out on a digital surface model (DSM) as opposed to a DTM, the ZTV map will indicate that the proposed development as visible from the top of the vegetation and rooftops of buildings. These types of results, although technically correct, are of little practical use in the Visual Impact Assessment (VIA). Height of proposed development
Recommended ZTV study area (radius)
<20m
5km
>=20m but <50m
10km
>=50m
45km
Table 1: ZTV area of study based on height of proposed development
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Presentation of ZTV maps 3.13. In order to ensure that ZTV maps are clearly legible, these shall be presented in the following manner: The minimum size of paper on which a ZTV map shall be printed is A2. The base map needs to be in greyscale to differentiate between the base map and the overlying ZTV map. The base map shall have the same exact dimensions as the ZTV map. The proposed development shall be clearly identified and labelled. Concentric rings to indicate the distance from the proposed development shall be shown on the ZTV map. Areas of potential visibility shall be shown by means of a transparent colour overlay. In the case of ZTV maps based on the building surface, a minimum of five highly‐contrasting colours shall be chosen for the colour overlays. These shall be highly contrasting; different shades of one colour shall not be used. The ZTV map shall include a legend to display in tabular form the meaning of each colour which has been used in the ZTV map. 3.14. The following information shall be included on the ZTV map and within the method statement: Name and details of GIS software Type and date of dataset If the dataset is derived from a DTM, the original cell size and whether this has been down sampled or thinned. If the DTM have been down sampled or thinned, the new grid spacing and amount of thinning shall be acknowledged. Whether the ZTV analysis was based on bare‐earth information Other relevant information, which although is not dataset or software specific, will affect the result from the ZTV analysis, such as viewer height and whether earth curvature has been included in the analysis. The ZTV area of study.
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4. Viewpoints 4.1.
Viewpoints are the locations from where a proposed project may be visible and are therefore likely to leave an effect on the environment and on the people (visual receptors) who experience it. The selection and number of viewpoints from which a proposed project is studied requires careful consideration.
4.2.
There are a number of issues which affect the selection of viewpoints. As a general rule careful consideration shall be given to those viewpoints where there are likely to be significant effects.
4.3.
The number of viewpoints will vary depending on a number of factors such as the scale of the proposal and its context. A large number of viewpoints can be unhelpful because significant impacts from certain viewpoints may not be given their due importance. On the other hand, a small number of viewpoints may overlook critical viewpoints from where there is the likelihood of a significant visual impact.
4.4.
It is essential that the visualisations demonstrate the proposed project in the wider landscape and visual context. This approach will facilitate the evaluation process even by those people who may not be able to visit all of the viewpoints.
4.5.
Although it is justified to study the impact of the proposed development from particular viewpoints, it is important that the viewpoints are representative of a range of views within the study area which in turn will lead to a reduction in the overall number of viewpoints.
4.6.
Different viewpoints shall be chosen to represent a range of viewers who are likely to experience the proposed project in a different way.
4.7.
Specific views of buildings or landscapes of high importance need to be studied from carefully chosen viewpoints. Although it may be inappropriate to modify the design due to the impact of the proposed development from one single viewpoint, it is still advisable to study the impact of the proposed development from these viewpoints.
4.8.
Specific views from particular viewpoints of the proposed building may provide sufficient information on its impact on the surroundings. Such viewpoints may be from culturally significant buildings, archaeological areas and natural heritage sites.
4.9.
Sequential viewpoints may be chosen to study the impact of the proposed development as one moves along a particular route.
4.10. Since the visual impact of a proposed development may increase when the visual receptor moves further away from this proposed development, it is important that the selection of viewpoints covers various distances and elevations.
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4.11. In certain cases, the visual impact of a building will be higher during different lighting and seasonal conditions. Local residents are likely to be effected when this happens and therefore it is important to study these effects. 4.12. ZTV maps illustrate the potential visibility of the proposed development in the landscape. ZTV maps are generated from “bare ground” topographic information without taking into account the effect of screening from vegetation and buildings and therefore their use will highlight areas where the proposed development may be visible. Actual visibility can only be determined by site survey. However, a ZTV map is of great help when planning field work since one knows exactly where an object definitely cannot be seen. 4.13. Fieldwork observation is another useful way to establish the potential visibility of the proposed project. Together with ZTV maps, it is an important tool in order to establish a set of provisional viewpoints that can later be refined through further assessment. 4.14. Although the selection of viewpoints shall be derived from a combination of different techniques, the possibility of establishing a database of important viewpoints must be given due consideration. This will facilitate the process of viewpoint selection and ensures that a number of key viewpoints are included in the study. Moreover it will facilitate the assessment of the proposed development especially in such cases where a cumulative impact visual assessment is required. 4.15. In the case when an EPS or EIS is being undertaken, the viewpoint list shall be prepared by the consultant in charge of the EPS or EIS. When EPS or EIS is not required, the viewpoint list shall be prepared by the client’s architects. In all cases, the final choice of viewpoints shall be agreed with the relevant authority prior to the undertaking of the photomontages. 4.16. The final set of selected viewpoints shall be established upon the completion of the ZTV and preliminary wireline diagrams. 4.17. The details of those viewpoints which shall be omitted from the final set of selected viewpoints may still need to be documented, for example in an EPS or EIS. 4.18. The selection of viewpoints should not involve unacceptable risks to those preparing and assessing the visualisations. 4.19. Whenever possible, all viewpoint positions should be marked on site with a peg or a surveyor’s pin.
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a.
The likelihood that the proposed development will create a significant visual impact.
b.
The relationship between residential areas, recreational areas, tourist routes and areas, culturally significant buildings, archaeological sites and natural heritage sites to the proposed development
c.
The distance and elevation of the visual receptor from the proposed development
d.
The use of sequential viewpoints along specific routes
e.
Modes of transport
f.
Different lighting and seasonal conditions.
g.
The size of the proposed development
Table 2: Summary of the main issues that influence the selection of viewpoints
Recording and presentation of viewpoints 4.20. It is important to record field conditions of the viewpoint location when the photographs are taken. Table 3 lists additional information which needs to be recorded. 4.21. All viewpoints should be numbered and their position and orientation shown on a site and viewpoint location map. This map shall be printed on an A3 size sheet. 4.22. When the final set of selected viewpoints has been established, this will probably mean that the initial set of viewpoints has been narrowed down. It is not recommended to re‐number the set of selected viewpoints since the omitted viewpoints may still need to be documented. 4.23. A detailed drawing of each viewpoint location shall be presented. This will enable assessors to locate and visit the same viewpoint. The drawing shall be presented at a scale of 1:1000 on an A3 size sheet and shall include the sheet number, viewpoint number and title, the geographic projection with respect to ED50 / UTM zone 33N, the approximate distance to the proposed development and the viewpoint altitude with respect to mean sea level (MSL). 4.24. A summary of images for all viewpoints shall be presented on a single A3 size sheet, as shown in Figure 10: Summary of baseline images taken from each viewpoint. 4.25. In addition to the summary of images for all viewpoints, the baseline photographs as taken from each viewpoint shall be individually presented on separate A3 size sheets and shall include the sheet number, viewpoint number and title, the geographic projection with respect to ED50 / UTM zone 33N, the approximate distance to the proposed development, the viewpoint altitude with respect to MSL, the camera height, the date and time when the photograph was taken, the camera type, the sensor size and the lens focal length.
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Viewpoint
Specification required
Location
Obtain, from land based survey, the geographic projection with respect to ED50 / UTM zone 33N, except for the following: When the distance of the viewpoint from the proposed development >750m obtain geographical projection with respect to ED50 / UTM zone 33N from Global Positioning System (GPS), large‐scale map or DTM. In all cases, a photograph of the tripod location is required.
Distance
Approximate distance to the proposed development.
Viewpoint altitude
Obtain viewpoint altitude from land based survey preferably with respect to mean sea level, except for the following: When the distance of the viewpoint from the proposed development >750m obtain viewpoint altitude with respect to mean sea level from GPS, large‐scale map or DTM. In all cases, the height of the camera above ground level shall be specified.
Conditions
Date and time
Camera
Camera type, sensor size and lens focal length.
Table 3: Recording viewpoint information
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Figure 9: A separate sheet for each viewpoint shall be presented which shall include a siteplan with the location and orientation of the viewpoint superimposed on the siteplan
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Figure 10: Summary of baseline images taken from each viewpoint
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Figure 11: A separate sheet for each viewpoint shall include a photo taken from that viewpoint
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5. Photography 5.1.
The preparation and presentation of reliable visual information is integral in assessing how a proposed development impinges on its surroundings. Certain photographic and image enhancing techniques may either drastically increase or decrease the impact of a particular development. In view of this, the aim of this section is to provide a set of guidelines so that photographs, not only in their own right but also as a component of photomontages are prepared and presented in a manner to enable an informed and unbiased understanding of the proposed project.
5.2.
The correct preparation and presentation of photographs and photomontages comes a long way to assist the assessors and public in evaluating of developments prior to being built. However two dimensional images cannot capture the visual experience one gets when actually being present on site. Light and atmospheric conditions as well as time of day may affect the clarity of objects within the photograph. Notwithstanding this, photographs and photomontages are indispensable tools to understand the landscape and how this will be affected with the proposed intervention.
5.3.
It is advisable that judgements involving photographs are made when one actually visits the same location from where the photographs were taken.
5.4.
Photography for use in the preparation of visual simulations requires high quality technical skills in taking good photographs and also requires knowledge on the different types of photographic equipment and how these can be put to good use to convey in the best possible manner the impact of the proposed development on the surrounding landscape.
Focal length and field of view 5.5.
The horizontal field of view (HFOV) describes the width of a view whereas the vertical field of view (VFOV) describes the height of a view. When the field of vision increases, the focal length decreases, and vice‐versa. The 50mm lens which has a diagonal field of vision of 46 degrees is similar to the field of view of the colour‐sensitive cones in the human eye and is a fair representation of what the human sees within the area of detailed vision.
5.6.
When photographing a landscape, there is a tendency to zoom out (by decreasing the focal length) to capture as much of the scene as possible. However this comes at the expense of the perception of scale and distance of more distant objects. The greater the distance of the viewpoint from the visual resource, the more the problem is amplified.
5.7.
Various studies have been carried out to establish which focal length best equates to our real life vision in terms of scale and distance in a landscape involving a range of distances. In general a more representative sense of distance
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can be achieved by using focal lengths between 70mm to 90mm. Printed images with a focal length of 50mm generally understate landscape scale. 5.8.
The 50mm focal length is widely used in the preparation of visual simulations and is normally the base photographic reference standard, even though it is recognised that as a printed image, the landscape scale is always under‐ represented.
5.9.
The 50mm single frame shall provide the natural photographic base for panorama construction, for the recalibration of greater focal lengths and for the production of transparencies for on‐site verification and assessment.
5.10. When the HFOV for baseline images and photomontages exceeds 40 degrees, a number of 50mm single frame images shall be carefully stitched together using suitable software.
Camera type 5.11. A high quality digital SLR camera with a full frame sensor (36mm wide by 24mm high) shall be used. Images taken with digital SLR cameras fitted with reduced size sensors will not be accepted. 5.12. The 50mm lens is widely used in the preparation of visual simulations. This guideline advocates the use of a 50mm fixed focal length lens. Fixed focal length lenses reduce the risk of errors in camera matching and are normally of a very high quality. Moreover fixed focal length lenses simplify the construction of panoramas, ensure compatibility of photography for all viewpoints and facilitate the verification of the image. 5.13. In some circumstances when an alternative lens other than the 50mm lens needs to be used, a 28mm fixed focal length lens shall be used. However this should be agreed with the determining authority prior to the photo shoot and a written justification shall be supplied.
Setting up and recording data 5.14. Whenever possible, cameras shall be mounted on a levelled tripod and a photo of the tripod set‐up should be included. 5.15. During the photo shoot, the information shown in Table 3: Recording viewpoint information shall be documented. 5.16. Photographs shall be taken in good visibility and in representative weather conditions. As a general rule they shall be taken during daytime when there is good ambient light. However prior to the undertaking of the photomontages, confirmation shall be obtained from the relevant authority regarding whether day time, night time or a combination of both are required.
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5.17. Photographs shall be devoid of foreground objects which partly or fully obstruct the view of the proposed building. 5.18. In general photos shall be taken in landscape format. 5.19. The camera height shall be 1.5m above ground level. When it is deemed necessary to change the height, the reasons for this change need to be documented. 5.20. Image enhancement is acceptable as long as the overall character of the image in unchanged. Operations such as the correction of exposure values, sharpening and colour balance are allowable since, when correctly applied, increase the quality of the image. On the other hand, operations such as cloning, painting and erasing should, in general not be used. 5.21. The original photograph for each viewpoint shall be submitted in RAW format by the applicant to the determining authority on request.
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6. Preparation and Presentation of Visualisations 6.1.
Visual simulations shall accurately represent a proposed change or addition to a landscape. Land‐based surveying, LIDAR data, on‐site photography and the production of accurate computer‐generated 3D models are important tools which, when used together, help to visually predict the impact of a proposed development.
6.2.
Visual simulations for each viewpoint shall consist of one or more of the following:
6.3.
In general, a visual simulation is prepared by:
6.4.
Baseline panoramas and matching wirelines, Matching photomontages, Single frame baseline images, and Single frame photomontages.
Establishing the viewpoints from where the photographs will be taken Taking of site photos using the appropriate photographic equipment Constructing the baseline panoramas from the site photos Constructing a 3d model of terrain, surrounding buildings and the proposed development to an LOD1 Positioning the viewpoints in the 3d model Producing the wirelines for each viewpoint Establishing the final set of selected viewpoints Constructing a 3d model of the proposed development to an LOD3 as described in Annex H: Level of detail Carrying out the necessary camera matching by using site photos, survey reference points and terrain features Preparing the panoramic and single frame photomontages.
When a 3d model of the terrain needs to be constructed, the following information shall also be submitted together with the visual simulation: Name of details of terrain modelling software Type and date of dataset If the dataset is derived from a DTM, the original cell size and whether this has been down sampled or thinned. If the DTM have been down sampled or thinned, the new grid spacing and amount of thinning shall be acknowledged.
Construction of baseline panorama 6.5.
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The baseline panorama shows the existing view and shall capture the overall visual context of the site. It shall consist of a set of 50mm images stitched together in order to provide better understanding of the relationship between
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the proposed development and the overall landscape. This, together with the wirelines and the photomontages are required for professional assessment. 6.6.
The baseline panorama shall have enough information to assist not only those involved in the evaluation of the project who have access to the site but also to those who cannot visit some or all of the viewpoints.
6.7.
Photographs shall be taken during daytime. However there will be instances when the impact of the proposed development needs to be studied during night‐ time. Instances when night time photographs need to be taken are when the proposed development includes areas which will require the use of flood lighting.
6.8.
Digital enhancement is not a substitute for poorly taken photographs. In such circumstances, the photographs need to be retaken.
6.9.
The photographs making up the baseline panorama shall be stitched together in planar projection using suitable software.
6.10. It is very important that before any stitching is carried out, the 50mm images shall first be resized to 216mm wide x 144mm high. 6.11. It is a common occurrence that minor adjustments to the scale and rotation need to be made in order to achieve a perfect match between the panorama and the wireline. 6.12. The baseline panorama will have a horizontal field of view of 65.5 degrees and a vertical field of view of 27 degrees. The image size shall be 385mm wide x 144mm high. 6.13. The image will have a principal distance of 300mm.
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Figure 12: Baseline panorama and matching wireline
Figure 13: Photomontage
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Construction of matching Wireline 6.14. Wirelines are simple line drawings which show the terrain profile in three dimensions. Normally they are devoid of existing structures but incorporate the proposed development in LOD1. Due to the different characteristics of each site, existing landscape features such as pylons or the existing buildings in the close proximity of the proposed development may need to be included in the wireline. Any structures included in the wireline shall be modelled in LOD1. 6.15. Wirelines are constructed from surveyed data (either from land surveys or DTM). Many GIS and 3d modelling packages are capable of producing wirelines from different types of datasets. 6.16. Since wirelines represent objective data, they are a valuable tool to the assessor who may compare these wirelines with the views on site, thereby making objective judgements on the likely visual impacts of the proposed development on the existing context. 6.17. In general the data used to construct the terrain profile is the same data used for the calculation of ZTV’s. 6.18. The wireline shall contain enough data in both the foreground and the background to easily match the wireline to a particular view. 6.19. The geographic projection of the wireline and the cameras shall be made with respect to ED50 / UTM zone 33N. 6.20. In order to enable direct comparison with the baseline panorama, the wireline is constructed with the same dimensions and geometry as the baseline panorama and for the same horizontal and vertical fields of view. The wireline shall also be rendered or stitched in planar projection. 6.21. The proposed development in the wireline shall be shown in a solid colour; it is recommended to use different colours to differentiate between the proposed buildings, the DTM and the existing development. 6.22. The proposed development in the matching wireline shall be shown centrally in the image unless there exists a valid reason to offset. A case in point is when the proposed development needs to be studied in relationship to an existing building.
Construction of matching photomontage 6.23. Photomontages combine a photograph with a computer‐rendered image of the proposed development. They are accurate representation of location, scale and general appearance of the change being proposed even though variations in environmental conditions may invariably influence the appearance and visibility of the various elements in the image.
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6.24. Since photomontages are digitally constructed, it is possible to either exaggerate or downplay the prominence of the proposed project. It is important that any enhancements do not alter in any way the character and scale of the proposed project and should only serve to improve the clarity of the overall image. 6.25. In order to enable direct comparison with the baseline panorama, the photomontage is to be constructed with the same dimensions and geometry as the baseline panorama and for the same horizontal and vertical fields of view. 6.26. It is important that the rendered image of the proposed development matches the baseline panorama as much as possible. This entails that any 3d model is accurately constructed and positioned on the digital terrain. Equally important is that the properties and location of the camera used for rendering match those of the physical camera used to take the photographs. 6.27. The lighting model used in the 3d model shall match those in the baseline panorama. Consequently, the position of the sun used in the 3d model shall have the same latitude, longitude, time, day and month as when the photographs were taken. 6.28. Since the rendered image will be superimposed and eventually composited on the baseline panorama, rendering must be produced in planar projection. If a number of computer renders are to be stitched, the type of projection which shall be used for stitching shall also be planar. 6.29. Changes to the vegetation shall be included in the photomontage. The proposed vegetation shall be modelled as detailed in the drawings of the proposed development. In general the painting of the proposed vegetation directly on the photomontage shall not be allowed. When it is deemed necessary to paint the proposed vegetation directly onto the photomontage, great care shall be taken so that the scale, positioning and the perspective of these elements are represented as accurately as possible. 6.30. The photomontage shall depict two stages in the landscaping scheme, namely a year 0 (i.e. no landscaping) and year 10 scheme. 6.31. When the proposed project involves substantial night time lighting, photomontages shall be constructed to illustrate it. This however involves a lot of painting on the baseline photographs making it very difficult to make an objective assessment. 6.32. The effect of blinking lights is normally studied in a Visual Impact Assessment. However this is practically impossible to depict using photomontages; computer animation would be a very useful tool to study its effect both during the day and night time. 6.33. The extent of the central 50mm single frame image shall be clearly defined to indicate the maximum clear area of vision seen by the human eye. Since the image height is 144mm, the width of this single frame image shall be 216mm. REF: VS 1.0
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6.34. The printed images shall be shown along with the following text: ‘The images contained on this page and the previous page (baseline panorama and matching wireline) are not representative of scale and distance from the actual viewpoint and show the proposed development in its wider landscape context only.’ 6.35. The photomontage shall contain the following information: sheet number, viewpoint number and title, the approximate distance to the proposed development, the camera height, whether the landscaping scheme is year 0 or year 10, the date and time when the photograph was taken, the camera type, and the vertical and horizontal fields of view of the panorama.
Single frame 75mm focal length baseline images and photomontages 6.36. 75mm single frame images are required for professional assessment and for the wider audience to provide a realistic impression of scale and distance. 6.37. The requirements for preparing single frame images are similar to those for preparing panoramas except for the requirements stated below. 6.38. 75mm single frame baseline images and photomontages for each viewpoint shall be submitted at a 75mm focal length recalibrated from the 50mm image. The VFOV shall be 18.2 degrees and the HFOV shall be 27 degrees. 6.39. The single frame photomontages shall depict two stages in the landscaping scheme, namely a year 0 (i.e. no landscaping) and year 10 scheme. 6.40. The 75mm single frame photomontages shall contain the following text: ‘This image should be viewed at a comfortable arm’s length (approximately 500mm)’. 6.41. The single frame images shall contain the following information: sheet number, viewpoint number and title, the approximate distance to the proposed development, the camera height, whether the landscaping scheme is year 0 or year 10, the date and time when the photograph was taken, the camera type, and the vertical and horizontal fields of view of the image. 6.42. All single frame images shall be produced to a standard image size of 390mm by 260mm high on A3 size sheets. This size will reduce the white space on the A3 and on the A4 sheets when the images are reduced in size for non‐technical purposes. Standardisation of image sizes also enables the verification of visualisations presented using transparencies. 6.43. When the HFOV of a proposed development exceeds 27 degrees, the width of the A3 sheet may be increased. The horizontal dimension of the sheet shall not exceed 840mm and the HFOV shall not exceed 54 degrees. The vertical dimension of the sheet and the VFOV shall remain unchanged.
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Figure 14: 75mm single frame baseline image
Figure 15: 75mm single frame photomontage
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Alternative focal lengths to single frame photomontages 6.44. Although every effort is to be made so that single frame photomontages will be presented at a 75mm focal length, there will be particular cases when the use of alternative focal lengths will be more appropriate. 6.45. When it is determined by MEPA that single frame photomontages shall be prepared at alternative focal lengths, these shall be submitted either at a 50mm focal length, or at a 28mm focal length. 6.46. It is up to MEPA to determine which focal length is the most appropriate for each particular viewpoint. It is important that this is established at an early stage of the application.
Single frame 50mm focal length baseline images and photomontages 6.47. The requirements for preparing 50mm single frame images are similar to those for preparing 75mm single frame images albeit with some noticeable differences. 6.48. Single frame baseline images and photomontages submitted at a 50mm focal length shall be presented in landscape format. The VFOV shall be 27 degrees and the HFOV shall be 39.6 degrees. 6.49. The single frame photomontage shall depict two stages in the landscaping scheme, namely a year 0 (i.e. no landscaping) and year 10 scheme. 6.50. The printed images shall contain the following text: ‘The image contained on this page is not representative of scale and distance from the actual viewpoint and shows the proposed development in its context only.’ 6.51. The single frame images shall contain the following information: sheet number, viewpoint number and title, the approximate distance to the proposed development, the camera height, whether the landscaping scheme is year 0 or year 10, the date and time when the photograph was taken, the camera type, and the vertical and horizontal fields of view of the image. 6.52. All single frame images shall be produced to a standard image size of 390mm by 260mm high on A3 size sheets.
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Figure 16: A 50mm focal length image in landscape format with a horizontal field of view of 39.6 degrees and a vertical field of view of 27 degrees.
Figure 17: Another 50mm focal length image in landscape format with a horizontal field of view of 39.6 degrees and a vertical field of view of 27 degrees.
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Figure 18 & Figure 19: A 50mm lens was used for these streetscape views. However a 28mm lens is more appropriate in these situations.
Figure 20: A 28mm focal length image in landscape format with a horizontal field of view of 65.5 degrees and a vertical field of view of 46.4 degrees.
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Single frame 28mm focal length baseline images and photomontages 6.53. When it is determined by MEPA that the proposed development cannot be satisfactorily represented by a 50mm focal length image, a 28mm prime lens shall be used instead of the 50mm prime lens. 6.54. Single frame baseline images and photomontages submitted at a 28mm focal length shall be presented in landscape format. The VFOV shall be 46.4 degrees and the HFOV shall be 65.5 degrees. 6.55. The single frame photomontage shall depict two stages in the landscaping scheme, namely a year 0 (i.e. no landscaping) and year 10 scheme. 6.56. The printed images shall contain the following text: ‘The image contained on this page is not representative of scale and distance from the actual viewpoint and shows the proposed development in its context only.’ 6.57. The single frame images shall contain the following information: sheet number, viewpoint number and title, the approximate distance to the proposed development, the camera height, whether the landscaping scheme is year 0 or year 10, the date and time when the photograph was taken, the camera type, and the vertical and horizontal fields of view of the image. 6.58. All single frame images shall be produced to a standard image size of 390mm by 260mm high on A3 size sheets.
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Annex A: Checklist: Zone of Theoretical Visibility Maps, Panoramas and Single Frame Images Item
Contents
Yes
No
Maps & Viewpoints
All specified viewpoints visualised
ZTV map
Site and Viewpoint Location map
Individual Viewpoint Location maps
Summary of baseline images from each viewpoint
Baseline photograph from each viewpoint
Photomontages
Baseline panoramas and wirelines (VFOV: 27o HFOV: 65.5o)
Year 0 photomontage panoramas (VFOV: 27o HFOV: 65.5o)
Year 10 photomontage panoramas (VFOV: 27o HFOV: 65.5o)
Single frame baseline images
Year 0 single frame photomontages
Year 10 single frame photomontages
Methodology Statement
Name and details of GIS software used for the ZTV
Type and date of dataset used for the ZTV
Original cell size of DTM
Whether DTM has been downsampled or thinned
Whether the ZTV analysis was based on bare‐earth information
Viewer height of ZTV analysis
Whether earth curvature has been included in the ZTV analysis
Type and make of camera
Lens type: 50mm fixed lens
Lens type: 28mm fixed lens
Sensor size: 36mm wide by 24mm high
Orientation of photograph: Landscape
Camera height: 1.5m
Photographs taken with tripod
Photograph of tripod
Avoidance of foreground objects
Weather conditions on site
Photomontage preparation method statement
Survey of viewpoints and reference points
List of drawings used for 3d modelling of proposed development
Planar projections for panoramas
Correct viewing instructions, technical data on images
a. b.
REF: VS 1.0
This checklist shall only be used when ZTVs, panoramas and single frame images are all being requested. The aim of this checklist is to assist the applicant to submit the correct and complete information. It is not an exhaustive list of all the requirements and therefore the applicant shall be fully conversant with the requirements as set out in this document.
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Annex B: Checklist: Panoramas and Single Frame Images only Item
Contents
Yes
No
Maps & Viewpoints
All specified viewpoints visualised
Site and Viewpoint Location map
Individual Viewpoint Location maps
Summary of baseline images from each viewpoint
Baseline photograph from each viewpoint
Photomontages
Baseline panoramas and wirelines (VFOV: 27o HFOV: 65.5o)
Year 0 photomontage panoramas (VFOV: 27o HFOV: 65.5o)
Year 10 photomontage panoramas (VFOV: 27o HFOV: 65.5o)
Single frame baseline images
Year 0 single frame photomontages
Year 10 single frame photomontages
Methodology Statement
Name and details of GIS software for wireline
Type and date of dataset used for wireline
Original cell size of DTM
Whether DTM has been downsampled or thinned
Type and make of camera
Lens type: 50mm fixed lens
Lens type: 28mm fixed lens
Sensor size: 36mm wide by 24mm high
Orientation of photograph: Landscape
Camera height: 1.5m
Photographs taken with tripod
Photograph of tripod
Avoidance of foreground objects
Weather conditions on site
Photomontage preparation method statement
Survey of viewpoints and reference points
List of drawings used for 3d modelling of proposed development
Planar projections for panoramas
Correct viewing instructions, technical data on images
a. b.
This checklist shall only be used when panoramas and single frame images are being requested. The aim of this checklist is to assist the applicant to submit the correct and complete information. It is not an exhaustive list of all the requirements and therefore the applicant shall be fully conversant with the requirements as set out in this document.
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Annex C: Checklist: Single Frame Images only Item
Contents
Yes
No
Maps & Viewpoints
All specified viewpoints visualised
Site and Viewpoint Location map
Individual Viewpoint Location maps
Summary of baseline images from each viewpoint
Baseline photograph from each viewpoint
Photomontages
Single frame baseline images
Year 0 single frame photomontages
Year 10 single frame photomontages
Methodology Statement
Name and details of GIS software for wireline
Type and date of dataset used for wireline
Original cell size of DTM
Whether DTM has been downsampled or thinned
Type and make of camera
Lens type: 50mm fixed lens
Lens type: 28mm fixed lens
Sensor size: 36mm wide by 24mm high
Orientation of photograph: Landscape
Camera height: 1.5m
Photographs taken with tripod
Photograph of tripod
Avoidance of foreground objects
Weather conditions on site
Photomontage preparation method statement
Survey of viewpoints and reference points
List of drawings used for 3d modelling of proposed development
Correct viewing instructions, technical data on images
a. b.
REF: VS 1.0
This checklist shall only be used when single frame images are being requested. The aim of this checklist is to assist the applicant to submit the correct and complete information. It is not an exhaustive list of all the requirements and therefore the applicant shall be fully conversant with the requirements as set out in this document.
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Annex D: Glossary of key terms ASCII Acronym for American Standard Code for Information Interchange is a commonly used format for exchanging computer data. An ASCII file is a point feature data set where each point stores a numeric value that represents a geographic attribute, such as elevation. It is commonly used in surveying and GIS related work. Angle of view The angle of view is the angle of subject area that is projected onto the camera’s sensor by the lens. Therefore it is the angle over which the sensor can ‘see’ through the lens. Computer‐aided design (CAD) Computer‐aided design is the use of computer systems to assist in the creation, modification, analysis, or optimization of a design. Cylindrical projection A method used to map a panorama onto a curved surface using software. The angle subtended by the arc is equal to the horizontal field of view. Digital Terrain Model (DTM) A topographic model of the earth’s surface devoid of any trees, buildings and other structures. The data files contain the spatial elevation data of the terrain in digital format. A DTM can be stored in several ways, namely contour vectors, a rectangular grid of equally spaced points or an irregular spaced set of points connected as triangles also referred to as a Triangular Irregular Network. Digital Surface Model (DSM) A digital surface model is a digital terrain model with trees, buildings and other structures. ED50 / UTM zone 33N The geographical coordinate system used by MEPA Environmental Impact Assessment (EIA) A study undertaken to establish the environmental effects resulting from a proposed development. The EIA findings are then incorporated in an Environmental Impact Statement (EIS) or an Environmental Planning Statement (EPS). Environmental Planning Statement (EPS) means the result of a limited environmental impact assessment study presented as a report which describes a development listed in Category II of Schedule IA (as described in L.N. 114 of 2007) and its effects on the environment indicating how these effects have been taken into account
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Environmental Impact Statement (EIS) means the result of a full environmental impact assessment study presented as a report which describes a development listed in Category I of Schedule IA (as described in L.N. 114 of 2007) and its effects on the environment indicating how these effects have been taken into account Field of view The field of view is a measurement (in millimetres) of the subject area. Focal length The focal length of a lens is the distance from the optical centre of the lens to the sensor when the lens is focused on an object at infinity. Geographic information system (GIS) A geographic information system is a computer system designed to capture, store, manipulate, analyse, manage, and present all types of spatial or geographical data. Level of detail (LOD) The level of complexity and the amount of information represented by a 3d model LIDAR A remote sensing technology which is used in surveying to create digital terrain models and digital surface models Panorama An image which has a horizontal field of view wider than that produced by a single 50mm lens which is usually taken as 40 degrees. It normally consists of a series of overlapping photographs stitched together using software. Photomontage A visualisation constructed from the superimposition of a digital 3D model upon a photograph or panorama in order to accurately portray, in a realistic manner as practically possible, a proposed change or modification in the landscape. Planar projection A method used to map a panorama onto a flat surface using software. Prime lens A lens that has just one focal length (in contrast to a zoom lens that covers a wider range of lengths). Principal distance The perpendicular distance from a printed image at which the exact perspective ‘as seen by the camera’ is reconstructed. SLR camera A type of camera that permits the photographer to view through the lens and see exactly what will be captured
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Triangular Irregular Network (TIN) A vector data structure that partitions geographic space into contiguous, non‐overlapping triangles. The vertices of each triangle are sample data points with x‐, y‐, and z‐values. These sample points are connected by lines to form Delaunay triangles. TINs are used to store and display surface models. Visual Impact Assessment (VIA) A visual impact assessment is a study to assess the visual impact of a proposed development on the landscape. Wirelines These are line diagrams that are based on DTM data and illustrate the topography in 3D. Wirelines may also include the proposed buildings or structures. Sometimes these are referred to also as wireframes. Zone of Theoretical Visibility (ZTV) Previously known as Zone of Visual Influence (ZVI), it represents the area over which a development could theoretically be seen. The ZTV is usually based on a ‘bare earth’ scenario.
Figure 21: Field of view, angle of view and focal length (top view)
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Appendix E: Taking good photographs The intention of this appendix is to set out in a concise manner the main issues relating to photography aimed at constructing panoramas suitable for photomontages as outlined in this document. Camera and lens A digital SLR with a full frame sensor (36mm wide by 24mm high) and a fixed focal length 50mm lens should be used. This will ensure that sufficient information can be captured, the images can be verified and reduce the risk of inaccuracies. Since the size of the sensor may vary even on full frame sensor cameras, it is important that this is checked; any significant variation from the standard sensor size should be recorded and if significant, corrected for. Tripod A properly levelled and stable panoramic tripod ensures that photographs are sharp and that the stitching process of the photographs can be executed satisfactorily. The height of the camera above the ground should be 1.5m. A photograph of the tripod in situ should be taken. Focus When autofocus is switched on, the focus can be different in successive frames of the panorama. A case in point is when there are foreground objects. When this happens, constructing a panorama from successive frames may be impossible. Moreover, images which are not all focused on infinity will each have a different principal distance. Consequently, the camera lens should always be focussed on infinity. Exposure Whenever possible, one exposure shall be used once for the complete panorama. This can be done by first establishing the best exposure to be used for all the frames and then locking the exposure on this value.
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Depth of field and aperture Depth of field is an optical property of a lens which means that only objects within a certain range from the camera will be in focus. The lens aperture, another optical property of a lens, controls the amount of light entering the camera, with larger apertures such as f/2 allowing more light to enter than smaller apertures such as f/16. For images such as landscapes, a large depth of field is usually desirable. The simplest way to control the depth of field is to change the aperture, with the depth of field increasing with decreasing apertures and vice versa. Other methods to change the depth of field are by controlling the distance from the camera to the main subject and by using a longer focal length. However, since as it has already been stated that a fixed focal length 50mm lens should be used, this method will not be discussed any further. Shutter speed Shutter speed should be selected in order to obtain the correct exposure consistent with the aperture selected. White balance Many digital cameras have a facility known as automatic white balance, which automatically compensate for ambient colour temperatures. This facility can have unforeseen consequences when taking panoramas and therefore the white balance should be set manually to daylight. Image sharpening Another feature which can be found in modern digital cameras is image sharpening. Image sharpening should be done in image processing software which ensures better panoramas and better compositing of photomontages. Therefore this option should be switched off.
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Appendix F: A3 single frame transparencies E1. Black and white acetates made from 50mm single frame images are a useful tool for verification and assessment. In this respect applicants may be required to submit transparencies for verification and assessment.
Figure 22: When the wireline is viewed at the correct distance and from the same viewpoint, the scale of the development can be assessed in the wider landscape
E2. Transparencies can be used on site to assess the scale of the development in the wider landscape. To enable accurate alignment with the landscape features, the assessor shall hold the transparency at the correct distance and view it from the same location and height of the original camera lens. E3. The size of the image shall be 360mm by 240mm and the viewing distance shall be 500mm, calculated from a camera with a full frame sensor and with a 50mm lens. The image shall contain the following text: “This image must be viewed with one eye from a distance of 500mm” E4. The images shall also include the sheet number, viewpoint number and title, the approximate distance to the proposed development, the camera height, whether the landscaping scheme is year 0 or year 10, the date and time when the photograph was taken, the camera type, and the focal length of the image.
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Figure 23: The transparency can also be used to assess the scale of the development in the wider landscape if the image is viewed at the correct distance and from the same viewpoint
E5. Before printing, the brightness and contrast of the image shall be adjusted so that there is sufficient transparency to enable the viewer to clearly and accurately align landscape features. E6. The image shall be printed on an A3 size transparency.
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Appendix G: Verification of panoramas and 75mm single frame images F1. The original single frame 50mm images with embedded metadata shall be submitted in RAW format upon request. F2. The metadata shall be used to check that a full frame sensor and a 50mm fixed focal length lens have been used. F3. To check that the panoramas have been prepared and presented as requested, the original single frame 50mm photograph which forms the centre of the printed panorama shall be resized to 216mm wide by 144mm high, printed on acetate and superimposed on the panorama. F4. To check that the 75mm single frame images have been prepared and presented as requested, the original single frame 50mm photograph shall be printed on A3 at 390mm wide by 260mm high. A template, similar to the one shown in Figure 24 is then overlaid onto the A3 sheet to check that the correct proportion of the image has been cropped. F5. The proposed development shall preferably be placed centrally within the panoramic image.
Figure 25: Verification template for 75mm single frame images.
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Annex H: Level of detail A1. LOD0 is essentially a Digital Terrain Model over which a map or an aerial image may be draped. Buildings are represented by footprint or roof edge polygons. Although LOD0 serves various 3d application requirements such as hydrological modelling, it cannot be considered as a true 3D model since it is a boundary representation in 3D with a height as an attribute. A2. LOD1 is also generally referred to as a block model. It consists of buildings superimposed on a Digital Terrain Model. Each building or building part of the generalised outer shell is represented by exactly one extrusion body (prismatic block model) thus the building roof is approximated by a horizontal plane. A3. LOD2 has differentiated roof structures and thematically differentiated boundary surfaces. Base areas, walls, roofs, exterior ceilings, exterior floors and building installations can be represented as semantic objects. A4. LOD3 is in practice an LOD2 with openings such as doors and windows. A5. LOD4 is an LOD3 upgraded with interior.
Figure 26: LOD1, LOD2 and LOD3
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