Sunseers too yellow

[billb]

Sunset/rise photos are way too yellow-little or no red. Changing WB has only small effect Using Pentax K-X

 

[KmH]

OK. We'll make note of that. :thumbup:

The way image sensors in digital cameras work. and the RGB color spaces camera makers offer us (sRGB or Adobe RGB), limit both the reds and the blues that a digital photo can show. File:Colorspace.png - Wikipedia, the free encyclopedia
Color space - Wikipedia, the free encyclopedia
Bayer filter - Wikipedia, the free encyclopedia
Active pixel sensor - Wikipedia, the free encyclopedia

 

[Garbz]

Also quite critically you may be overexposing. When the red pixels saturate and you start making things brighter still your green pixels start to increase which turns your camera towards the yellow.

Then there's also the issue of calibration. I have yet to see a camera which actually properly reproduces a faithful colour checker chart, because quite frankly we want pictures that are amazing and not pictures that record what we see. As such there's often quite a few colour variances between cameras, and even between raw processors. If you use Lightroom I suggest you head down to the HSL tab and move the hue sliders for the yellow to the red if you want more red. Alternatively head to the very bottom under camera calibration and you can move the hue for your entire primary colour. Or alternatively again you can create your own camera profile.

 

[billb]

Thanks to both of you. I think, however, that something else is going on as well. As a physicist as well as an amateur photographer I am driven by curiosity as well as aesthetics. The ccd is capable of capturing red. A red flower in sunlight registers as red; overexpose several stops,, and it looks washed out, but basically red, definitely not yellow. At sunrise reddish rocks in foreground appear same as my eye. Red clouds well above horizon are red. Red clouds on horizon (before sunrise) are yellow. Long path through atmosphere? UV? I do not use a 1a or UV filter (as I did in the past with film). Do I need one with dslr?

 

[Garbz]

No. DSLRs are not very UV sensitive and the glass used in lenses isn't either.

Here's a simple test. Next sunrise underexpose the image dramatically. Check the histograms, ensure that the far right of the histogram shows no overexposure on any individual channel (not a combination of three) and then see if you still have a problem.