Another reason not to photograph in the heat of the day

[John Chardine]

A lot is talked about harsh light during midday hours and how important it is to take advantage of the light around sunrise and sunset. Lately I have been forced to shoot in harsh sunlight in the late morning through middle of afternoon (high tide times and other constraints) and I have noticed another huge problem- that of heat shimmer. When it is bad even images at 10 m with the 500mm lens suffer. Symptoms are softness, OOF, just plain horrible. I'm still trying to figure out what conditions produce this kind of effect but I've noticed lately that beaches can be really bad. Yesterday was hot for here (about 29°C) and the sand was giving off a lot of heat. Some of my images of Piping Plover chicks, which are only a few centimeters above this hot sand, suffered badly.

I'm wondering- Many BPNers live in very warm climates where this must be a constant problem, no?

As a final thought, it is probably important as well to let your lens equilibrate to outside temperatures before you shoot, and this may also be a part of my problem.

[Axel Hildebrandt]

If there is heat flare, I don't think it would help much if the lens has the same temperature as the surrounding. Even in the winter you can run into this problem. I tried to photograph pipits out of my car. Because of the wind direction the heat of the engine block caused heat flare and the images didn't look good.

[Charles Glatzer]

Nothing you can do about heat shimmer, except get as close as possible and/or use shorter focal length lenses. Longer lenses compress atmospheric conditions. When the weather turns inclement rain, snow, heat shimmer, blowing dust, sand, etc I opt for my shorter lenses and more animalscape type images.


BTW- those not in know will often blame lenses, and/or bad camera AF for the poor images taken under these conditions.

Best,

Chas

[Michael Pancier]

or you can opt to shoot infra red which shines during the midday harsh hours.....IR has made productive days out of what would be bad light....;)

[Declan Troy]

Not just a warm weather issue. This summer I had unsolvable heat shimmer issues up along the Beaufort when temps were barely above freezing. When the sun comes out there can be distortions in the air that become exaggerated as distance and magnification increase. No point waiting for sunset; few subjects are willing the wait a couple of months for that to happen!

[Don Anderson]

This is a problem in MN. in the winter.. If you try to shoot out of a car with the heater on,
your images will be soft from the heat distortion. So dress warm and leave the heater off.
As mentioned, the engine heat and exhaust can also mess with your images expecially below
zero.

[Eric Virkler]

I used to work as a land surveyor and "heat shimmer" can be a problem in any season, it just rears its head most often on hot, sunny summer days. The heat radiating of the surface (blacktop for instance) produces air with a different density that the rest of the air. The light rays bend as they pass through this air. On really bad days, I've looked through my equipment (it has 30x magnification) at the prism set up as my backsight, and watched as the prism jumped from one side of the viewfinder to the other. Impossible to take an accurate shot unless you aim for the middle of the jumping prism and guess, and definitely impossible to obtain sharp, usable images. Your only option is to use the diffraction to your advantage and go for an impressionistic look.

Eric Virkler
Faces of Nature Photography
www.ericjvirkler.com (http://www.ericjvirkler.com)