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04-22-2007, 07:40 PM   #1
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K10D, WB and color histograms

I have tried to find a WB setting that gives me better color histogram readings. I have posted my findings at DPR. For those interested in not blowing the channels but still want to expose a bit to the right.

K10D, WB and color histograms

Sorry Mo for cheating on the forum...

04-22-2007, 09:06 PM   #2
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Looks good Jonas
04-23-2007, 09:54 AM   #3
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Thank you Cideway,

Lol - I guess one interested out of 100 views is ok. Pretty close to a total waste of bandwidth though...
04-23-2007, 11:27 AM   #4
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QuoteOriginally posted by Jonas B Quote
Thank you Cideway,

Lol - I guess one interested out of 100 views is ok. Pretty close to a total waste of bandwidth though...
Hi Jonas, cheer up. I'm sure plenty went to the dp-review page. Since this site is a banned site there, no point in linking to here People generally don't want to be bothered w/ cut/paste and fix a link.... Having not fallen for the "siren song" of the k10, not much to say but good work....

04-23-2007, 12:50 PM   #5
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QuoteOriginally posted by Jonas B Quote
Thank you Cideway,

Lol - I guess one interested out of 100 views is ok. Pretty close to a total waste of bandwidth though...
Jonas,

I tried, really I did.

The problem with DP (And to some extent here as well) is all the 'complete quotes' inclusions. Pages and pages of what the first guy said in the second guy's message all so that second guy can say "Nice job 1". Here (PF) it's marginally understandable as a self-defense against untimely deletions but there(DPR) it comes in as lots and lots and lots and lots of noise!

My eyes go crossed, then roll back, my mind wonders...

Do us(me) a favor and summarize the result into something new I can try/apply -vs- something else that I might normally/formerly do. I'll be happy to give it a try and let you know my results and thoughts.
04-23-2007, 11:44 PM   #6
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Well done, so end of line, for the histogram to be reliable one should use WB 5000K no matter what light there is. At least that’s what I recall from reading the thread very late last night.
04-24-2007, 12:15 AM   #7
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QuoteOriginally posted by Jonas B Quote
Thank you Cideway,

Lol - I guess one interested out of 100 views is ok. Pretty close to a total waste of bandwidth though...
Me too! I found it very interesting - even if I couldn't follow it all.

Working through the threads over there is painfully tedius. I finally copied and pasted a couple out of the thread, saved them, and assumed I could always find my way back when my stock of patience was replenished. Like Gimbal, I'd like to hear your short and sweet version of the results to make sure I understood what your conclusions were.
04-24-2007, 05:47 AM   #8
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QuoteOriginally posted by Jonas B Quote
I have tried to find a WB setting that gives me better color histogram readings. I have posted my findings at DPR. For those interested in not blowing the channels but still want to expose a bit to the right.

K10D, WB and color histograms

Sorry Mo for cheating on the forum...
I'm determined to not go back to dpreview, so I gave yours a quick click just to make sure I was correct in my assumption of your testing.

Since the histogram is based on the JPEG produced by the camera, it will produce a different histogram based on the JPEG settings of the camera. It will do this even if you are recording RAW only. Since that is the case, I wonder if you can mimic the same results of adjusting the temperature by adjusting the JPEG settings.
When I was traveling, I shot 2MP JPEGs for quick viewing on the laptop, and I found that bumping up the contrast and saturation produced a better view on the dismal laptop screen. Making those contrast/saturation adjustments had a noticeable impact on the histograms, primarily pushing the reds farther right. I have since used similar settings to keep from blowing the red channel and have had success.

I tend to like using a more pleasant color balance while shooting, hence I would prefer not keeping the temperature at 5000 all the time. I also know the temperature of the lights in my house (2800K, they are not normal incandescent) and have had pretty decent luck using that setting.

What do you think?

04-24-2007, 11:35 AM   #9
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QuoteOriginally posted by jfdavis58 Quote
Jonas,

I tried, really I did. ... -snip- My eyes go crossed, then roll back, my mind wonders...

Do us(me) a favor and summarize the result into something new I can try/apply -vs- something else that I might normally/formerly do. I'll be happy to give it a try and let you know my results and thoughts.
Ok: A semi controlled test using some reasonably decent tools tells us thet the K10D color histogram shows values that are closely related to the level of saturation (at sensor level) if we set the WB to K5000 - no matter where we use the camera, or what the light is.

This can be useful for those shooting raw, and if we don't care what the colors on the LCD screen look like. (those=we=I?)

The background is, as carpents mentions in his summary, that the color histogram is influenced by the JPF settings. This is because the histogram is made up from the JPG embedded in the PEF/DNG file.

Conclusion: I, and maybe some more, get a way more reliable color histogram when shooting indoor or in mixed light by just leaving the WB setting to K5000 rather than to AUTO or some fixed value.



QuoteOriginally posted by Gimbal Quote
Well done, so end of line, for the histogram to be reliable one should use WB 5000K no matter what light there is. At least that’s what I recall from reading the thread very late last night.
Exactly. As I have had the K10D for a week only this isn't tested over time. This far it seems to work fine, outdoors as well as indoor (and I always try to exposure to the right).


QuoteOriginally posted by Rick Quote
Me too! I found it very interesting - even if I couldn't follow it all.

Working through the threads over there is painfully tedius. I finally copied and pasted a couple out of the thread, saved them, and assumed I could always find my way back when my stock of patience was replenished. Like Gimbal, I'd like to hear your short and sweet version of the results to make sure I understood what your conclusions were.
See above.

QuoteOriginally posted by carpents Quote
I'm determined to not go back to dpreview, so I gave yours a quick click just to make sure I was correct in my assumption of your testing.

Since the histogram is based on the JPEG produced by the camera, it will produce a different histogram based on the JPEG settings of the camera. It will do this even if you are recording RAW only. Since that is the case, I wonder if you can mimic the same results of adjusting the temperature by adjusting the JPEG settings.
When I was traveling, I shot 2MP JPEGs for quick viewing on the laptop, and I found that bumping up the contrast and saturation produced a better view on the dismal laptop screen. Making those contrast/saturation adjustments had a noticeable impact on the histograms, primarily pushing the reds farther right. I have since used similar settings to keep from blowing the red channel and have had success.

I tend to like using a more pleasant color balance while shooting, hence I would prefer not keeping the temperature at 5000 all the time. I also know the temperature of the lights in my house (2800K, they are not normal incandescent) and have had pretty decent luck using that setting.

What do you think?
If you have had succes trying not to blow the reds, and also had pretty decent luck using the K2800 setting, well, then everything is fine. That's what I think.

(In my series of test shots I also tried different values for contrast and saturation. They didn't affect the color histogram very much. From the discussion at DPR I understand that this might be becasue of my target (the Gretag 24-patch color chart). With another target with a larger area of one or two colors the settings should affect the color histogram more. That's probably what you have experienced in real life situations.)

But then again, if you want better luck than decent you can try a higher setting. It all depends on how far to the right you want to place the red channel when shooting. I guess you have a routine that works fine for you (judging from your pictures).

to all:

This is all about learning to know the equipment. I don't recommend people to always do what I say. These are just my findings, something I like to learn in the process of learning a new tool. Or maybe rather; a way I like to do it and something that makes sense to me. Some will just continue to shoot JPGs, some don't like it when the LCD screen colors are off and others again already have other ways, that suits them, to work.

yours,
04-24-2007, 02:04 PM   #10
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QuoteOriginally posted by Jonas B Quote
This is all about learning to know the equipment. I don't recommend people to always do what I say.
Right. But it's kind of like fishing.

Instead of having to put the boat in and start working the whole ocean looking for success, at least we know the general area of where the fish are.

In other words, your experimenting provides both a good starting point and food for thought in general.
04-24-2007, 03:25 PM   #11
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QuoteOriginally posted by Jonas B Quote
Ok: A semi controlled test using some reasonably decent tools tells us thet the K10D color histogram shows values that are closely related to the level of saturation (at sensor level) if we set the WB to K5000 - no matter where we use the camera, or what the light is.

This can be useful for those shooting raw, and if we don't care what the colors on the LCD screen look like. (those=we=I?)

The background is, as carpents mentions in his summary, that the color histogram is influenced by the JPF settings. This is because the histogram is made up from the JPG embedded in the PEF/DNG file.

Conclusion: I, and maybe some more, get a way more reliable color histogram when shooting indoor or in mixed light by just leaving the WB setting to K5000 rather than to AUTO or some fixed value.

OK, So I shoot RAW, with WB set to 5000K and get a more dependable histogram in all light conditions,

-VS-

Shooting RAW with any other WB.




Sounds like a plan.




A couple of questions:

What are "some reasonably decent tools (that) tell[s] us" this histogram related to saturation thingy?

What WB temp do you use in the conversion to RGB?
04-24-2007, 03:51 PM   #12
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QuoteOriginally posted by jfdavis58 Quote

A couple of questions:

What are "some reasonably decent tools (that) tell[s] us" this histogram related to saturation thingy?

What WB temp do you use in the conversion to RGB?
The tools used were the Malykh-Gordon PEF Analyzer (a small piece of software that looks into the PEF file and gives a histogram-like GIF picture in return showing the levels of the red, blue and 2xgreen channels), a Kodak grey card, a Gretag standard 24-patch color chart, constant light (daylight type bulbs) in one case and a semingly constant overcast sky in the other. This was combined with my brain and ACR 3.7 and alltogehter "reasonably decent".

I just do it the same way most people do I guess; either per taste or a combo of a test shot of the Gretag CC (or a grey card) and a profile (Rag's script) in ACR. Or a combo of both plus curves. I experimented with the plugin "InCamera" for a while but it's overdue and not necessary for me. I'm a happy amateur only.

Did I misunderstand any question just ask again.

regards,
04-24-2007, 04:24 PM   #13
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QuoteOriginally posted by Jonas B Quote
The tools used were the Malykh-Gordon PEF Analyzer (a small piece of software that looks into the PEF file and gives a histogram-like GIF picture in return showing the levels of the red, blue and 2xgreen channels), a Kodak grey card, a Gretag standard 24-patch color chart, constant light (daylight type bulbs) in one case and a semingly constant overcast sky in the other. This was combined with my brain and ACR 3.7 and alltogehter "reasonably decent".

I just do it the same way most people do I guess; either per taste or a combo of a test shot of the Gretag CC (or a grey card) and a profile (Rag's script) in ACR. Or a combo of both plus curves. I experimented with the plugin "InCamera" for a while but it's overdue and not necessary for me. I'm a happy amateur only.

Did I misunderstand any question just ask again.

regards,
Not being to software literate,
I downloaded some java lib files of the Malykh software ect. How do you get this to work??
04-24-2007, 05:18 PM   #14
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Hardware calibration confirmation?

QuoteOriginally posted by Jonas B Quote
The tools used were the Malykh-Gordon PEF Analyzer (a small piece of software that looks into the PEF file and gives a histogram-like GIF picture in return showing the levels of the red, blue and 2xgreen channels), a Kodak grey card, a Gretag standard 24-patch color chart, constant light (daylight type bulbs) in one case and a semingly constant overcast sky in the other. This was combined with my brain and ACR 3.7 and alltogehter "reasonably decent".

I just do it the same way most people do I guess; either per taste or a combo of a test shot of the Gretag CC (or a grey card) and a profile (Rag's script) in ACR. Or a combo of both plus curves. I experimented with the plugin "InCamera" for a while but it's overdue and not necessary for me. I'm a happy amateur only.

Did I misunderstand any question just ask again.

regards,
Hi there Jonas, thanks for this work. I have still not read all comprehensively, however what I have read still impresses as a great individual starting point (considering the wide variation of viewing/printing environments). For an absolute global solution it would be interesting to confirm or fine tune the accuracy of your software findings via a hardware solution like Printfix Pro or (my personal choice) X-Rite: X-Rite Photo Marketing
Cheers
Stomie
04-24-2007, 08:23 PM   #15
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Thanks for taking the time to share your findings with us.

Have you thought about setting up a website for these kinds of posts? It would be nice to have this kind of stuff all in one place instead of buried in a forum that only allows searching sporadically.
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