Posted by Lindy Martin on February 21, 2012 at 10:00 AM
I was out taking some snowy owls yesterday and encountered heat haze issues. Any thoughts on how to get around that focusing issue. Rather disappointing day with good preening and fligt shots that are all OOF.
Posted by Jim DeWitt on February 21, 2012 at 2:42 PM
Lindy -
"Heat haze" is an imprecise word. If you mean the blurring of distant images because of rising warm air from the ground, the only solution I know is to get there earlier before the sun heats the ground. Heated air is less dense, and the boundaries between the cold and warm areas refract light differently, resulting in the shimmer.
The problem is quite pronounced in the subarctic spring: the sun heats the dark ground or dark water quite quickly, and the surrounding colder air much more slowly. Air heated by the ground rises through the much colder air on top of it. The result is images even a hundred feet away are blurred by differential refraction.
If you mean true haze - dust and obscuring gases in the air - then a UV filter can be some help, depending on conditions. But it's not always useful.
If your images are truly out of focus, not blurred by rising warmer air, then you have a mechanical problem with your lens or camera you need to check out.
Discussion
1 replies"Heat haze" is an imprecise word. If you mean the blurring of distant images because of rising warm air from the ground, the only solution I know is to get there earlier before the sun heats the ground.
The problem is quite pronounced in the subarctic spring: the sun heats the dark ground or dark water quite quickly, and the surrounding colder air much more slowly. Air heated by the ground rises through the much colder air on top of it. The result is images even a hundred feet away are blurred by differential refraction.
If you mean true haze - dust and obscuring gases in the air - then a UV filter can be some help, depending on conditions. But it's not always useful.
If your images are truly out of focus, not blurred by rising warmer air, then you have a mechanical problem with your lens or camera you need to check out.
Jim DeWitt
Frozen Feather Images