I was processing a couple of photos yesterday and found that they had this nasty blur or glow around brighter areas:
Blur around bright area in photo, 300% crop
Blur around road markings, 200% crop
I was wondering what was causing this glow or blooming, and thought that possibly it might be CCD Blooming. After some reading, and checking the EXIF on the images that had this problem (most of the photos seemed to be okay), I found that the images displaying the glow/blur/blooming problem were all taken with my Tokina 10-17/3.5-4.5 fisheye zoom lens, and with the lens wide open.
The problem was that I'd been shooting with my 50/1.4 lens, which I'd been using at a wide aperture to get a shallow depth of field. I'd then switched to the fisheye lens, but forgotten to close down the aperture (I'm always forgetting to check or change the camera settings). Photos taken with the fisheye lens stopped down (f/8) didn't have this glow, so obviously it was caused by shooting the lens wide open (f/3.5-4.5).
So now I know the cause of and fix for this problem, I just need to fix my memory so I remember to stop the lens down when needs be! Hopefully this post will be useful for anyone else seeing the same phenomena in their images.
Leave a Reply