Gauntlet: Avoid Tunnel Vision

By Gary Fong
Photographer:  Dave Bartruff,
Click Photos to Enlarge
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Picture editors notice the little things when editing a shoot.  It may be the nuance of the coverage, the style of the photographer, or the technical defects.
Dave Bartruff, has been around the world chasing the sun for over 40 years.  One of his more recent projects was in Egypt, the land of blazing sun, hot sand, and Pyramids that have been around just a few years longer than Bartuff himself.
Now for the Nit Picking
While editing 20gb of pictures, a handful where showing vignettes on all four corners. Darkened corners tend to move the eye back to the main subject, but the Bartruff dark corners were a bit too prominent, more like intrusive.
At first, I thought it could a tree branch that caught the corner of a frame…or a camera strap that missed the neck. But two, three or four corners is unusual.  I searched my mind for what could create these defects and why they were showing up all too consistently. Throughout many of Bartruff’s images were deep blue sky, sun and sand images, and dark corners.
I asked Dave if he was using a Polarizer. “Oh yes”, he said. At IOS 200, 1/1000, f/22, the desert seemed blinding. He tried toning down the brightness of the desert with a Polarizer. The Polarizer had the added benefit of making the sky go deep blue.
But what was causing the vignettes?  When Dave added the Polarizer, he placed it over his Skylight 1A filter, already on the lens.  The combination of stacking two filters created a tunnel effect for the angle of view, thus shows the vignette defects.
The solution is not stacking filters on top of each other.  Use only the Polarizer or the Skylight 1A over the lens, not both. However, sometimes with super wide-angle lenses, a Polarizer may still show up at the corners.  A thin Polarizer may be the answer.  Some filters are taller than others.
If a Photoshop solutions is available, use the “clone tool” to dab out the offending dark defect around the corners.  Sample the same color tones around the area, then dab with a soft brush tool. But even that becomes problematic if the surrounding area is something other than simple sky colors, i.e. tree branches.  
Yes, there are other Photoshop techniques that could be applied for the solution. But let’s backup to the first question…if one could avoid shooting a defect, try avoiding it in the first place.