RK Hobbs
Figural 2, March 2022 Nude and clothed figure photography on film
On the Cover ...
Gazelle Powers splashing in the Little Paint Branch River. I used a Lensbaby Twist 60 to mimic a Petzval lens, and a blue filter to push the tonal response of the film toward wetplate territory. 20th century technology, 19th century look. I’m so far out of date . . . Thanks to the professional models who appear in this issue:
Z Walsh and Tiffany Helms Z’s IG: @ZtheBug, @ZWalshPhotography TH’s IG: @tiffanyhelms_, https:allmylinks.com/tiffanyhelms Gazelle Powers IG: @gazellepowers, beacons.page/gazellepowers Lolita Marie IG: @la.la.Lolita, www.littlemisslolita.com Sarah Marzipan IG: @marzipanned All images are copyright 2022 Robert Hobbs, all rights reserved. Contact me at Hobbs@rkhobbs.com
Z Walsh and Tiffany Helms
Gazelle Powers
Lolita Marie
Sarah Marzipan
The Swirl Explained The first portrait lens developed for photography was the Petzval, named for the man who developed it. It was simple, but carefully calculated, and was very popular in the first few decades. The distortion created by the two doublet lens results in a signature ‘swirl’ in the out-of focus area. There are some later lenses which exhibit the same effect for the same reason, particularly lenses based on Zeiss’ Biotar design. The swirl effect itself is technically a defect, eliminated in most modern lens designs. The circles of confusion created by the shape of the aperture should be the same from the center to the edge in a well-corrected lens, but in the Petzval and similar lenses the circles flatten out toward the edge of the lens. These circles of confusion define the character of the ‘bokeh’ or out-of focus area. From a petzval lens, the bokeh circles would distort like this: Image Center
Image Edge
As these distorted circles join to form the out-of-focus area, they tend to create the illusion of three-dimensional concentric circular movement.
Because the circles are ‘squashed’ into ovals, the illusionary movement seems to happen along the concentric lines. In other words, the blur looks like it goes around the center instead of equally in all directions. The effect, like most bokeh effects, is most pronounced where there are lots of small bright bits, like lights or the openings between leaves in the out-of focus areas.
The photograph of Keira Grant on this page, and the images of Gazelle Powers on the cover and the pages that follow this, were made on 35mm film using a Lensbaby ‘Twist 60’ which is designed to mimic the effect of thePetzval Portrait Lens. You can see the distortion in the sparkly highlights from the water surface increasing toward the edge of the image on the left.
These images of Gazelle Powers were taken with a Lensbaby Twist 60, which creates the same kind of distortion as the Petzval lens. These lens designs also show curvature of the focal plane, so that when the center is in focus, the edge is not. The combination of concentric swirl and focal vignetting direct the eye toward the center. (I also used a blue filter to create a 19th century tonal response.)
I snuck one variant in here. The image on the left was taken with a modern well-corrected lens. The out-offocus area is smooth and even and the focused image is sharp from center to edge. Compare with the image on the right, in which the swirly bokeh creates a sense of movement in the still background. (I like them both, different flavors for different feels.)