Here in Newfoundland we get many foggy days. I am looking for advice on how to post process photos taken so as to make them look more like those taken without the fog. That is how do people improve the saturation, contrast etc of photos taken in the fog. TIA
Gene,
Fog presents a big challenge. Contrast can be very low and if you want to boost it, noise is enhanced. To minimize that problem, use the lowest ISO you can get away with, and expose to the right. This will give you the highest signal-to-noise ratio. (By the way, the noise in such images is pretty much all due to photon noise.) Then correct the image with the levels tool, using the left and right sliders. Hold down the alt key (on windows) when moving the slider and it will alert you to when you are clipping. Use of the shadow/highlight tool can cause halos, so I use levels first.
A problem when stretching such images is light fall-off. You may need to correct the light fall-off first. I think CS4 has tools to do that. There are other methods which I can get into if anyone is interested, but does require other software.
Gene- For a simple method when you want to remove the foggy look, try Ps Levels and click the Auto button. I don't often use Auto but it works a treat on fog. See the example.
BTW- that's Newfoundland fog! Best kind. Made at Cape St. Mary's.
John,
I believe auto levels does a 2% histogram clip by default. This means that 2% of the pixels will be clipped on each end. I remember changing that to 0% (years ago in an older version of photoshop). I don't know if that is still the default, nor do I remember how to change it. I haven't used auto levels in years. If you are using auto levels it would be worth checking into the clip points.
It is .01 whatever that equates too in % ;), also in S/H as well. You can change the auto defaults in Curves/Layers by clicking on the Auto Color Corrections options (very small down arrow located far right in tabs) setting them to 0 and checking save as default.
Chas
Last edited by Charles Glatzer; 08-03-2009 at 08:56 AM.