gdanmitchell
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 Re: 5dmk2, problems with pure reds (and sometimes blues) | |
skibum5 wrote:
I\'m suspicious that they can be born out in practice, although I haven\'t carefully tested so I\'m not sure.
I have a feeling that you are saying something interesting, although I haven\'t read it carefully enough to understand, so I really cannot say... ;-)
crazeazn wrote:
its just a canon + red thing.
Nope. It is a DSLR plus red (or any hot color channel) thing. :-)
Access wrote:
gdanmitchell wrote:
We are trying to make this way too complicated. If the OP simply reduces exposure a bit to avoid blowing out the red channel the problem will almost certainly be resolved. This may require some post-processing adjustments to bring up the darker area of the image, or some alternative like exposure blending. And this will be the case with a 5D or a 5D2 or just about any other DSLR making such a photograph.
Okay I spent some more time with this, playing with the raws and the bracketed shots from that day and one other test shot I did of a nearly pure red sweatshirt. And I think I see what you are saying. In some cases I have to underexpose by as much as 4 EV to get a proper exposure that does not blow out the reds.
But when I get that proper exposure, I can then apply the post I want and things look okay. Sure if I go down to the pixel level, I can still spot the artifact with the pure red parts of the photo, but that\'s not a big deal to me. It must be minimized enough to the point where it\'s not a problem when viewed at more normal resolutions.
Thanks all, I really do appreciate the help.
You are welcome. I have had a lot of experience with this, and it doesn\'t create problems for me anymore when I consider the nature of the scene I\'m photographing... which has always been necessary in photography.
In many cases, the camera (almost any modern camera) can do a creditable job of automatically coming up with an exposure that is \"close enough for jazz,\" and sometimes it can do just as well as a smart, experienced photographer making manual adjustments. But when the scene presents complex exposure challenges (huge dynamic range, unbalanced overall color, multiple light sources of different temperatures, etc.) there is no AE system that can automatically make the \"right\" choice, much less the best choice. A smart and experienced photographer exercising experience-based good judgment can still outsmart the camera in such cases.
It is kind of pointless to blame the camera...
Another alternative is to use a color filter (cyan in this case), which change (balance) the temperature of light and let you keep a higher exposure without blowing a channel.
I\'ve read that suggestion before, but I don\'t think it is going to work quite the way you imagine... unless you are going to be happy with the very \"distorted\" color balance that results. If you do want \"natural\" color - e.g. - very hot in one channel as in the original scene - once you compensate for the filter in post you\'ll be more or less back where you would have been had you simply avoided blowing out the hot channel at the time of exposure.
Take care,
Dan
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