Shooting in Manual mode

Get off Auto! This could really be the title of this chapter but we also understand the convenience of automatic settings on the camera in many situations. Especially if you are shooting in a scene where the light may suddenly change or you need to act fast to get the shot.

But it also means that when you are in auto mode you have either none, or at least very little control over what your camera is actually doing when you press the shutter release button.

Setting your camera in manual mode naturally requires you to understand the relationship between aperture, shutter speed and ISO settings and how they affect the exposure of your image. This may be a little intimidating at first but understanding these vital parameters is guaranteed to elevate your photography.

The illustration below, also called the “Exposure Triangle” will help you understand the relationship between aperture, shutter speed and ISO settings:

APERTURE: Aperture refers to the size of the hole in the lens in which the light comes through onto the camera sensor. The aperture setting is referred to as f-stop value and a wider aperture allow in more light and therefore a brighter image. The aperture scale can get at little tricky to understand as a smaller f-stop value represents more light and a higher f-stop value equals less light.

Each full f-stop as shown below equals 1 EV (Exposure Value) which again means the double or half the amount of light. The aperture also controls the depth of field in your image. This refers to how much in your scene will appear to be in focus. A narrow aperture then means a deeper depth of field whereas a wider aperture gives us a shallower depth of field.

So to summarize, f/16 as an example, is a narrow aperture setting and will let in less light but gives you a deeper depth of field.

SHUTTER SPEED: Just as with the aperture setting the shutter speed also controls the amount of light allowed onto the camera sensor. Again this is measured in full f-stops but as with the aperture it can - and often is - set in smaller incremental steps, typically 1/3 or 1/4 stops.

Faster shutter speeds (indicated in fractions) such as 1/250 second will allow less light through the lens and slower shutter speeds such as 1/4 second will allow for more light to come through.

Typically for handheld operations of your camera you would be in the 1/30 - 1/500 range as increasing the shutter speed is prone to camera shakes and vibration and would require using a tripod. From this we can conclude that faster shutter speeds will help freeze motion and longer shutter speeds will help capture low light situations and/or create motion blur.

ISO ISO is the description of your cameras sensitivity to light. The higher the number the brighter the image will be. The ISO scale is easy to relate to as each doubling of the number equals 1 full stop, or 1 EV (50, 100, 200, 400, 800 etc).

It is worth noting that any camera has what is referred to as “native” ISO. This means that this is the ISO setting where the camera performs as its best in terms of image quality. It is so, that the higher the ISO setting is the more noise you will inadvertently add to the image.

So using the ISO setting is an evaluation of the scene. If you are shooting moving people in a scarcely lit room you would use a high ISO to freeze the motion, but with added noise as a compromise.

If you were to shoot a night scene on tripod, you would use a low ISO but a longer exposure time as this would not add noticeable noise to the image.

So the relationship between aperture, shutter speed and ISO are important and changing one of these will require you to change one of the others in order to maintain the same exposure, i.e. if you want a narrower depth of field you lower the aperture setting (remember, higher number=less light) -1 f-stop and increase either the shutter speed or ISO value equally with +1 f-stop.

Photo Peter Fauland, Berlin