How do reds come out in your 5d3 ?

K-amps

EOR R
Aug 8, 2011
1,790
1
Indianapolis
I have often struggled with red objects in my 5d3. I wrote last year about it but did not get any replies. Yesterday while trying out my new 85 1.2 ii, I saw the same issue.

Red flowers come out in an over saturated red haze. The other colors seem saturated just fine, but the reds are over powered so much that the flowers lose detail.

I can reduced saturation in LR, but then the whole image looks washed out... the issue is only with reds.

If I reduce just red (Red channel only) , then it lacks punch, although I get back details in the flower...

Has anyone else observed this?
 

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K-amps

EOR R
Aug 8, 2011
1,790
1
Indianapolis
Finally I get it where I have good saturation AND details. but takes me 5 minutes to dial it in LR with these settings:

There has to be better way than having to work on the reds so much.

These where all shot/ processed in RAW in LR 4.4
 

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Jim Saunders

EOS 6D MK II
Sep 9, 2012
1,125
14
hhaphoto.com
I just had this fist-fight with my 1Dx; I found that calibrating colours with a colorchecker passport got the shade right, and then selectively dropping the exposure on red bits by around 0.6 got them sorted. Oddly enough it wasn't the reds that shifted on the histogram, but blues.

The images in order are as imported; lens profile; color profile and finally the upper flower dropped down 1/3 stop with a brush stroke in LR5.

Then again to compare them back to back for this one I might leave the exposure; I definitely agree that they're troublesome. I was out shooting some red uniforms under fluorescent light a week or so ago and post on those was a real pain.

Anyway I'll get a more useful response together tomorrow.

Jim
 

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jrista

EOL
Dec 3, 2011
5,341
23
jonrista.com
You need to use per-channel color editing to bring down the red saturation independently of the rest of the colors. I've purposely increased the overall saturation on this rose photo of mine, then pulled down the reds, magentas, and purples to correct the oversaturation of the flowers without affecting the saturation of the greens:

 

K-amps

EOR R
Aug 8, 2011
1,790
1
Indianapolis
Tks guys for the responses.

Jon, I did try the per channel red.... but it did not fix the issue, just washed out the red. In real life the flower has more red chroma, and I can match it on screen, but then all details are washed out.... it's not that easy of a fix... moreover I'd like a perm fix rather than spending hours everytime I shoot red.
 

jrista

EOL
Dec 3, 2011
5,341
23
jonrista.com
K-amps said:
Tks guys for the responses.

Jon, I did try the per channel red.... but it did not fix the issue, just washed out the red. In real life the flower has more red chroma, and I can match it on screen, but then all details are washed out.... it's not that easy of a fix... moreover I'd like a perm fix rather than spending hours everytime I shoot red.
You can get it right. It may just require tweaking all of the color channels. If your willing to share the RAW, I can play around with it.
 

K-amps

EOR R
Aug 8, 2011
1,790
1
Indianapolis
Let me know if this works:

https://onedrive.live.com/redir?resid=6B9B43DE47D8F292!107&authkey=!ACdE2UxlWoEM-mo&ithint=folder%2cCR2
 

jrista

EOL
Dec 3, 2011
5,341
23
jonrista.com
What do you think of this?



I chose the "Camera Faithful" profile under Camera Calibration. The settings can be seen in this before/after comparison:

 

FEBS

Action Photography
Bobmanrea said:
Intensive reds are often out of gamut.

The easiest way is to select ProPhoto color space and not smaller as Adobe RGB or S-RGB and chose to work in 16 bit mode.
Then manual proof the color values ​​into a smaller color space as Adobe RGB and later on convert to the destinated color space as Adobe RGB or S-rgb.
There are no profile instructions how a RGB conversion properly is done between a larger color space and a smaller. Therefore proofing in the colors in to a smaller color space is the best way to go with out color clipping in red. But first, make one copy in S-RGB and one in Prophoto and you immediately see the difference in the shades of red in Prophoto due the much larger color space.
Good luck
The 5D3 can only write a file in Adobe RGB or S-RGB. Do you have experience then that a photo taken in Adobe RGB and uploading in LR or PS gives better result in Prophoto color space? Where would that supplemental detail come for your Prophoto color schema?
 

rs

EOS 6D MK II
Dec 29, 2012
1,024
0
UK
FEBS said:
Bobmanrea said:
Intensive reds are often out of gamut.

The easiest way is to select ProPhoto color space and not smaller as Adobe RGB or S-RGB and chose to work in 16 bit mode.
Then manual proof the color values ​​into a smaller color space as Adobe RGB and later on convert to the destinated color space as Adobe RGB or S-rgb.
There are no profile instructions how a RGB conversion properly is done between a larger color space and a smaller. Therefore proofing in the colors in to a smaller color space is the best way to go with out color clipping in red. But first, make one copy in S-RGB and one in Prophoto and you immediately see the difference in the shades of red in Prophoto due the much larger color space.
Good luck
The 5D3 can only write a file in Adobe RGB or S-RGB. Do you have experience then that a photo taken in Adobe RGB and uploading in LR or PS gives better result in Prophoto color space? Where would that supplemental detail come for your Prophoto color schema?
It can only write jpegs in those colour spaces. Raw files are taken and stored with the only colour space constraints being that of the sensor itself. The raw converter will then apply a colour space which may or may not introduce further gamut restrictions.
 

FEBS

Action Photography
rs said:
It can only write jpegs in those colour spaces. Raw files are taken and stored with the only colour space constraints being that of the sensor itself. The raw converter will then apply a colour space which may or may not introduce further gamut restrictions.
OK, thx.

I didn't realize that the raw file is not according a colour space. However strange that Canon places a _ in front of the raw filename, in case you choose for AdobeRGB, while the raw file is independent of the colour space as you mentioned.
 

philmoz

EOS 80D
Jan 30, 2014
126
0
FEBS said:
I didn't realize that the raw file is not according a colour space. However strange that Canon places a _ in front of the raw filename, in case you choose for AdobeRGB, while the raw file is independent of the colour space as you mentioned.
Keeps the filenames consistent if you shoot RAW + JPEG.

Phil.
 

FEBS

Action Photography
Bobmanrea said:
Yes if you are shooting JPG you can only chose between Adobe RGB or S-RGB in the camera

I thought you used RAW where one of the color spaces is Prophoto, and also the largest one which is handy when you are dealing with intensive colors and nuances.
No, I'm shooting raw only, but was not aware that the setting of colour space had no influence on the raw file, but only on the jpeg.
So, once again I learned something from CR friends.

Thank you.
 

mackguyver

Master of Pain
I do a lot of macro work with flowers and see this a lot, and not just with reds, but blues and yellows as well. It's an issue with the capture, not the post-processing. The camera's meter is tricked by the strongly saturated colors and while it is metering the red channel correctly, but you have underexposed the blue and green channels (see histogram), and by "crushing" the shadows, you have oversaturated those colors. If you look at the screen shots, you'll see those channels are spiking on the left side.

The solution is to use the RGB histogram mode on the camera and when you see this, bump up the exposure until the shadows are no longer blocked, probably just +1/3 or 1/2 EV. It sounds counter intuitive, but it works.
 

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mackguyver

Master of Pain
P.S. here's some information from Michael at Luminous Landscape (from Optimizing Exposure):

"For example, with a typical DSLR, when photographing a red flowers under natural daylight, the LCD histogram will typically show the red channel as blown out. This doesn't tell whether the native raw red channel is actually blown. So one doesn't know whether to increase the exposure for ETTR, or reduce it. The natural reaction of most users is to say, "Uh oh, I'm gonna blow the red channel in these flowers, so I better reduce the exposure till the red histogram doesn't look blown out anymore." Unfortunately, that's almost always the wrong thing to do. In fact, the red channel (in the raw data) rarely clips on a typical DSLR with a normal daylight exposure, because the red sensitivity is very low (about 1.5 stops darker than green). If one was to reduce exposure till the red histogram no longer showed clipping, then the actual raw red channel would be very underexposed with a poor SNR. Result: noisy red flowers!

One colleague reports that he measured the relative sensitivity of the R, G and B of his DSLR at 5500K daylight (per daylight film). The ratio between the channels was very close to (G:B:R) 5:2:1. That helps explain the reasoning above. Food for thought."

They also have a nice tutorial on a good method to fix them, if you have already underexposed the image: Restore Those Clipped Channels