Experiment: Aperture Stacking
Exploring depth of field with bracketed apertures
Posted Sep 19, 2010
After reading about techniques like focus stacking, where depth of field can be increased by combining images with different focal distances - I got an idea.
Is it possible to gain more control over depth of field by combining multiple exposures taken at different apertures? A wide open aperture can create an atmospheric feeling with a shallow depth of field. This elective focus can make a scene appear less scientifically rendered. I think it can bring natural, emotional qualities to an image. When shot wide open, most faster lenses have a tendency to capture a softer image with less detail. Maybe combining exposures at different apertures would let me select the best characteristics of both large and small apertures.
Combined f1.4 (background) & f11 (foreground)
I spent a few minutes capturing images at an aperture of f1.4 (big hole, shallow depth of field) and f11 (small hole, deep depth of field). As best I could, I focused on the power plant, then combined the results:
My setup includes a Panasonic G1 and Minolta MC 58/1.4. The smaller Micro Four Thirds sensor on the G1 doubles the focal length of the lens to 116mm. Considering the distance to the power plant, I focused to infinity, pretty much nullifying any shallow depth of field that a large aperture creates.
Rollover to compare the foreground f1.4 exposure
While every lens is different, in this case, at f1.4, softness isn't just contained to the out of focus areas. The entire image loses detail and becomes less contrasty. Overlaying the f11 exposure introduces a crisp, clearly defined foreground. Keeping the f1.4 exposure visible in the background does do a lot to pop the edge of the power plant, creating a sense of distance.
Something about that soft image I really like. I think need to try this in a more complicated space...