I'm usually not one to ask these types of questions. To be honest, this topic would in no way affect how I go out to shoot and it won't cause me to re-examine my gear bag. I'm just wondering if it is something other here noticed in their cold weather outings.
Over the coldest weather of the winter I observed that my most used 17-40L seemed to exhibit more CA than usual. I didn't shoot with my other lenses much, so I don't know if it is limited to just the 17-40. No, it wasn't anything major, just slightly more pronounced than usual. The CA was magenta/green like usual, just visible through a larger portion of the image. I've seen this in temps below 15F. Above freezing the CA retreats back to barely noticable on my EF-S camera.
My guess is that the cold resulted in a minor change of volume in the glass, changing the optical properties. The affect wasn't permanent.
I suspect you're right - slight contractions in the glass elements.
Ken
Posted by Les Barstow on March 3, 2008 at 10:49 PM
I haven't noticed a significant difference on my lenses, but it isn't implausible. Those lenses are ground to exacting detail to minimize CA, and even the slightest change in shape could alter the lens properties.
Nothing is much different in what I'm shooting. I didn't suddenly start to shoot much higher contrast scenes. I'll try to post some examples when I have a chance.
Bill, I would have to leave my camera in the freezer overnight and then take a shot inside the freezer to replicate the conditions. If I took the camera out of the freezer to take the shot, I believe I would have a rather foggy image.
Posted by Bill Pelzmann on March 4, 2008 at 10:07 PM
...If I took the camera out of the freezer to take the shot, I believe I would have a rather foggy image...
Discussion
6 repliesOver the coldest weather of the winter I observed that my most used 17-40L seemed to exhibit more CA than usual. I didn't shoot with my other lenses much, so I don't know if it is limited to just the 17-40. No, it wasn't anything major, just slightly more pronounced than usual. The CA was magenta/green like usual, just visible through a larger portion of the image. I've seen this in temps below 15F. Above freezing the CA retreats back to barely noticable on my EF-S camera.
My guess is that the cold resulted in a minor change of volume in the glass, changing the optical properties. The affect wasn't permanent.
Mel-
Ken
Could it be that you are just shooting generally higher contrast scenes?
How about trying to reproduce it at home?
Take a shot and then stick your camera in the freezer for awhile.
Bill, I would have to leave my camera in the freezer overnight and then take a shot inside the freezer to replicate the conditions. If I took the camera out of the freezer to take the shot, I believe I would have a rather foggy image.
Yes, I know, that's why I had the