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02-04-2010, 02:27 PM   #91
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QuoteOriginally posted by tlwyse Quote
But if you know that it's coming out of the camera as AdobeRGB, if you then opened the image in Photoshop and assigned/tagged it with AdobeRGB would it still produce "bad" results? I'm just asking as I never use JPEGs out of the camera except for "proof" images. Everything else is raw.
Photoshop can detect the DCF 2.0 optional color space definition since at least CS2 (and maybe CS), but not in 7.0. I personally try not to use Photoshop unless I have to.

Sure, if you KNOW the file should be in AdobeRGB, you can assign it that color space and it'll look fine. But what's the point if you only use JPGs for proof anyways? What benefit do you get from having the camera generate JPG files in AdobeRGB? Only wide-gamut monitors can display it properly, and only if the application you're using can tell it's supposed to be in AdobeRGB. Even your camera's monitor will display it wrong.

02-04-2010, 02:44 PM   #92
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QuoteOriginally posted by GoremanX Quote
Even your camera's monitor will display it wrong.
I'm not sure that this is such a big deal, I use the screen on the back of my camera to confirm the capture (plus all the ancillary uses) but completely disregard it as being a colour reference. Firstly there's no way to "calibrate" it but by sight, second the ambient light in which it is viewed will affect the colour accuracy of the display in any case.
02-04-2010, 02:53 PM   #93
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QuoteOriginally posted by tlwyse Quote
Are you implying that it's not necessary to save your image in 16bpc but to simply keep it 8bpc since Photoshop still processes it "as if" it's 16bit?
When you open an 8bpc file and do color transformations, Photoshop does all the calculations in 16bit right up until you save, at which point the colours are interpolated back to whatever is determined in your file format. The end result is kind of irrelevant, because you're still starting and ending with an 8bpc file. You haven't added any color information, you've just done the color transformations more precisely.

But if your target is the utmost color fidelity, then you still need to start with a 16bit image. ACR and Photoshop are not the same application. ACR passes the color data to Photoshop in either 8bit or 16bit, and that step is important to ensure that Photoshop gets the right initial color data. In any case, I'd rather work with 16bit files throughout the whole process. That actually DOES increase the number of colors available me, unlike AdobeRGB which just changes which colors are available.

It's all kind of irrelevant for this thread, because the camera doesn't let you choose 8bpc/16bpc. It only lets you pick sRGB or AdobeRGB in 8bpc. I don't remember for sure, but I don't think JPG even allows 16bpc.

The upcoming versions of Gimp will also work this way, with an internal color engine that works in 16bit at all times. It can even be enabled right now, experimentally.
02-04-2010, 03:21 PM   #94
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QuoteOriginally posted by distudio Quote
I'm not sure that this is such a big deal, I use the screen on the back of my camera to confirm the capture (plus all the ancillary uses) but completely disregard it as being a colour reference. Firstly there's no way to "calibrate" it but by sight, second the ambient light in which it is viewed will affect the colour accuracy of the display in any case.
You should try the experiment on a K-7, which has a much clearer VGA screen than your K-x or K20D. The difference is way more noticeable there, similar to what I perceive on my computer monitor. I tried to come up with an example of the difference like you did earlier in the thread, but the only second camera I have is a crappy old super zoom and it takes horrible pictures.

02-05-2010, 01:19 AM   #95
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QuoteOriginally posted by GoremanX Quote
You should try the experiment on a K-7, which has a much clearer VGA screen than your K-x or K20D. The difference is way more noticeable there, similar to what I perceive on my computer monitor. I tried to come up with an example of the difference like you did earlier in the thread, but the only second camera I have is a crappy old super zoom and it takes horrible pictures.
It's nothing to do with the screen resolution, it's just that visual calibration is very limited and the fact that the ambient light colour temperature is variable makes the notion of calibration a nonsense.
02-05-2010, 02:35 AM   #96
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QuoteOriginally posted by distudio Quote
It's nothing to do with the screen resolution, it's just that visual calibration is very limited and the fact that the ambient light colour temperature is variable makes the notion of calibration a nonsense.
Technically that's true of any monitor, not just the camera's. For example, a laptop or netbook. But the fact remains, on my K-7, the visual difference between a picture taken in sRGB and AdobeRGB is quite large and noticeable in any light. The AdobeRGB one looks much worse. I really wish I could get a picture of it to show you, it's pretty dramatic.

If the in-camera viewing application was color-managed, there would be no visual difference between the two. Just like there's no visual difference between the two when I view them on my color-managed system with proper color spaces assigned to each picture (because my monitor is not wide-gamut).
02-07-2010, 12:46 AM   #97
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Ack! When I made my last post in this thread yesterday, I was playing around again with the color space setting on my K-7.

I went out to shoot some scenery pics today, and when I came home, I realized my camera was still set to AdobeRGB colorspace! All the JPGs looked like crap in my photo organizer (which does not detect the stupid DCF 2.0 optional color space tag). I had to open each one in an image editor, assign the right color space, and then convert it to sRGB before re-saving it again. Now they look "right".

Luckily I still have the DNG files, so I don't mind re-saving the JPGs. But what a pain... I'm really resenting this AdobeRGB setting on the camera. It's caused me nothing but aggravation.
02-07-2010, 06:02 AM   #98
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I sent Pentax an email about the AdobeRGB mode on the K-x. When you select AdobeRGB, none of the special post-capture functions are applied, including lens correction and chroma correction. I suggested that they at least disable the functions when AdobeRGB is selected so we’ll know they’re not being applied.

Pentax said they forwarded my suggestion to the development team in Japan. So…that’s not gonna get fixed any time soon...if at all. (oy vey.)

I generally stick with sRGB, but if I know I’m going to be photographing bright green foliage I’ll go with AdobeRGB because my Canon MP970 seems to print the greens “greener”, as opposed to sRGB which always seems to give bright greens a touch of a yellow cast in prints.

Of course, both appear with the yellow cast on the monitor.

02-07-2010, 09:21 AM   #99
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Um, I thought it was common knowledge that images for the web go to sRGB and images for print go to aRGB....

this horse was already dead before it got beaten....

uploading aRGB files to the web is kind of like listening to my girlfriend talk. she has SO MUCH information she needs to tell me about every little detail of her day that I just tune her out. I miss much of that information but I just let it go because I don't have the capacity to process all of that information.

uploading sRGB to the web is SELECTING THE PROPER TOOL FOR THE JOB.

It's just two different color spaces used for two different jobs.

have a beer.
02-07-2010, 09:22 AM   #100
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QuoteOriginally posted by GoremanX Quote
Ack! When I made my last post in this thread yesterday, I was playing around again with the color space setting on my K-7.

I went out to shoot some scenery pics today, and when I came home, I realized my camera was still set to AdobeRGB colorspace! All the JPGs looked like crap in my photo organizer (which does not detect the stupid DCF 2.0 optional color space tag). I had to open each one in an image editor, assign the right color space, and then convert it to sRGB before re-saving it again. Now they look "right".

Luckily I still have the DNG files, so I don't mind re-saving the JPGs. But what a pain... I'm really resenting this AdobeRGB setting on the camera. It's caused me nothing but aggravation.

Dude why didn't you just write an action for changing the colorspace and run it in a batch process for all of the pics?
02-07-2010, 10:53 AM   #101
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QuoteOriginally posted by MJB DIGITAL Quote
Um, I thought it was common knowledge that images for the web go to sRGB and images for print go to aRGB....
Additionally, unless you have a calibrated wide-gamut monitor, if you're post-processing, remember to work by number, not appearance, and print proofs to make sure you're going in the right direction, because you literally won't be able to see what you're doing.
02-07-2010, 11:49 AM   #102
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QuoteOriginally posted by MJB DIGITAL Quote
Dude why didn't you just write an action for changing the colorspace and run it in a batch process for all of the pics?
I said it was a pain, I didn't say it took forever I only had 30 pictures to do. It was shorter and easier to just open and re-save, and I really don't care if I add compression artifacts. The JPGs are only used to identify which DNGs I want to process, kinda like giant thumbnails. The JPG snapshot embedded in the DNG files is horribly compressed and ugly (and currently in AdobeRGB, thanks to the incorrect camera setting)
02-07-2010, 11:54 AM   #103
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QuoteOriginally posted by MJB DIGITAL Quote
Um, I thought it was common knowledge that images for the web go to sRGB and images for print go to aRGB....
After 7 pages of debate, it's been determined that that's not actually the issue here. The issue is the way in which AdobeRGB is specified in JPG and TIF files from the camera. Many color management-aware applications do not detect it as AdobeRGB and assume sRGB, thereby ruining the colors. If the user doesn't notice this, he/she ends up with crappy colors in his/her pictures (for print or for web). Most newer Adobe products can detect the colorspace properly, but not everyone uses Adobe products.
02-07-2010, 03:35 PM   #104
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QuoteOriginally posted by MJB DIGITAL Quote
Um, I thought it was common knowledge that images for the web go to sRGB and images for print go to aRGB....

this horse was already dead before it got beaten....
Um. no. The preconception that you hold is what this thread is all about, it's probably best to read back through.
02-07-2010, 03:37 PM   #105
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QuoteOriginally posted by GoremanX Quote
I said it was a pain, I didn't say it took forever I only had 30 pictures to do. It was shorter and easier to just open and re-save, and I really don't care if I add compression artifacts. The JPGs are only used to identify which DNGs I want to process, kinda like giant thumbnails. The JPG snapshot embedded in the DNG files is horribly compressed and ugly (and currently in AdobeRGB, thanks to the incorrect camera setting)
Of course the problem would have been magnitudes larger if you had preselected the incorrect in camera WB (which I have done, ie tungsten on a bright sunny day. RAW+ fortunately) ;-)
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