Color Space Capture on 1 Series

[MDJAK]

The following is copied from an essay appearing on the website luminous-landscape.com. By no means am I in any way intending to violate anyone's copyright by placing this here. I merely have a question about it.

Is this color space available on the camera, or is this some custom space imported into the camera?




"The use of a color space able to contain all the colors the 1DsMark II is able to reproduce is very important as Michael shows in his article on Adobe RGB vs. Pro Photo RGB (http://www.luminous-landscape.com/tutorials/prophoto-rgb.shtml). I personally use a wide color space and not Adobe RGB for the reasons Michael mentions in his essay. For years I have been using Ektachrome Space, J. Holmes, an RGB color space designed by Joseph Holmes and originally intended to hold the color gamut of Ektachrome transparencies. While I use almost exclusively Fuji Velvia when I shoot film it turns out that the color gamut of both Velvia and Ektachrome fit very nicely in this color space. When I started working with digital captures, first with the 300D and now with the 1DsMarkII, I decided to also use Ektachrome Space because it is a wide color space and because it made my workflow a lot simpler since I could use the same color space for all my images, film and digital.
Ektachrome Space, J. Holmes has one additional advantage: it comes with a set of 16 Chroma Variants which allow you to increase or decrease the saturation of an image anywhere from plus or minus 06 to plus or minus 50. This saturation increase or decrease is done by changing the colorspace, not by actually over saturating the colors. Each Chroma Variant is actually an individual color space which appear in Photoshop's color space drop down list. This approach means that you do not loose any of the data in the image because you can return to a different saturation setting at any time. It is also much more effective, in my estimate, than using the saturation sliders in Photoshop . This feature makes Ektachrome Space unique."

[BrandonSi]

It was my understanding that color space was independent of RAW. Once your RAW program nterprets that RAW data it then assigns it a color space of your choosing.

[scottbergerphoto]

You choose in the camera either sRGB or Adobe RGB. The resultant jpeg will have the attributes of the color space you select. The Raw file can be assigned to any of the available color spaces in the Raw Convertor you choose. You can "develop" the same Raw file into each different color space. I work in Adobe RGB.

[CyberDyneSystems]

The "Ektachrome Space, J. Holmes" color space he is referring to in the article above is NOT set on the Camera..

It is being used in Photoshop.....

So no.. you can't use it or "import it" into the 1D.

As ScottBerger says.. you don't have to anyways. Your RAW images have no color space untill one is assigned during or even after conversion.

[CyberDyneSystems]

MD could you also provide the link to the article you quote?
I read MR's article on Prophoto Vs. Adobe.. and now I want more ! :)

[slin100]

Technically speaking, RAW images do have a colorspace: the camera's native colorspace. Otherwise, the RAW converters wouldn't know how to interpret the RAW RGB data. What do you think happens when you choose a colorspace in the RAW converter? The RAW converter converts from the camera's colorspace to the chosen colorspace! Colors that don't fit in the new colorspace are mapped based on the rendering intent. The RAW converter uses the same color conversion engine used when you manually convert the colorspace of an image.

Unfortunately for us, camera manufacturers usually don't provide much detail about the camera's native colorspace. 3rd party RAW converters do their best to guesstimate the colorspace. Photoshop ACR, for example, has two profiles for each camera model: one for D65 lighting and one for incandescent illuminant A (2850K). It interpolates or extrapolates, as necessary, the color profile for all other color temperatures.

If you want to insure that no colors are clipped during the conversion, the new colorspace must have a gamut wider than that of the camera. Again, because we don't know exactly the details of the camera's colorspace, the safe choice is a large colorspace. It's very likely that Adobe RGB is not wide enough. That's why some use an even bigger colorspace. Prophoto RGB is a popular choice among the real sticklers. In practice, however, it'll probably be fine to use Adobe RGB for the majority of images.

[J Rabin]

MDJAK:
A comment from a person, me, who has used ProPhoto RGB for couple of years. I originally started using it when scanning my slides, because, for landscape photos, ProPhoto RGB holds greens and yellows from E-6 processed slides that the other common free color spaces couldn't contain. Heck, Prophoto RGB can contain and hold color outside human vision or printability!
A similar workspace is Adobe Wide Gamut or Wide Gamut Compensated RGB. The Ektachrome one is another sophisticated E-6 process color space.

When I went digital, and started shooting RAW, I started using ProPhoto RGB for my base 16-bit TIF archive file. When you are using ACR, specifying the color space for the first time, and chosing ProPhoto, it is obvious how much more detail does not get clipped in the strong greens and yellows. You can just compare the histograms and see this before conversion in ACR.

For people, candid, PJ, street, flash, studio photography uses I doubt using ProPhoto RGB "adds value" to final image quality. The color range in these images is not there. I no longer use ProPhoto RGB for these photography times and just use Adobe RGB for print, converted to sRGB for web.

Because I have the RAW file to reconvert in the future, I no longer need to use ProPhoto RGB as the 1st generation end-all-be-all archive TIF file. I do still use it when scanning E-6 Kodachromes, etc., because there is no RAW to fall back on.
I still use ProPhoto RGB to convert RAW of landscapes loaded with greens, yellows, and reds.

Some 6 ink and 8 ink printers can print Adobe RGB and BEYOND. Particularly the 8 ink models like the Canon 9900/9950. In these prints, greens, yellows, some reds are subtlely better. In other cheaper printers, printing from ProPhoto results in out of gamut rendering intent color shifts. BAD. Yuck.

As usual, when reading the excellent Luminous-Landscape site, many of the recommendations have maximum benefits in landscape fine art photography. But, just like "Expose to the Right" shouldn't be a religion (does not work well in PJ candid flash photography), never should one slavishly use ProPhoto RGB all the time.

It's just another tool to use on the appropriate images.

One guy's opinion.
Jack

[slin100]

Jack,

I like your opinion. I have one comment below.


Some 6 ink and 8 ink printers can print Adobe RGB and BEYOND. Particularly the 8 ink models like the Canon 9900/9950. In these prints, greens, yellows, some reds are subtlely better. In other cheaper printers, printing from ProPhoto results in out of gamut rendering intent color shifts. BAD. Yuck.


If a color is out of the printer's gamut, then it has to be remapped. There are many places where this can be done.


In the RAW converter by choosing a colorspace that fits in the printer's gamut
In Photoshop's Convert Profile command
In Photoshop's print dialog when doing full color management in Photoshop
In the printer driver when Printer Color Management is selected in Photoshop
You probably got your bad results from using option #3 or #4 and got good results from #1. You actually have more control by using #2 because you can see which colors are out of gamut by turning on Gamut Warnings. Then you have all of Photoshop's tools at your disposal to bring those out-gamut-colors back into gamut.

[J Rabin]

Jack,
Then you have all of Photoshop's tools at your disposal to bring those out-gamut-colors back into gamut.

Slin. Ahh. Thanks. Of course you're likely right. But I just can not spend all that workflow time in PS doing these processes. I'm not a PS saavy geek.
I have found that with Bruce Fraser's RAW book, I can get 80% of the image right, right in ACR. Followed by some sharpening and maybe, only maybe, a color correction layer or two. From here I want to print and move on. If I have to EVEN VIEW gamut clipping, do saturation changes, workspace conversion, I've lost time and lost the edge.

So, I just refuse to think about printing ProPhoto to a cheap inkjet or photo store crap kiosk. That's why I expressed it. I just can't manage doing those with the time available.

I will experiment though. Thanks. Jack

[slin100]

I just checked out the Michael Reichmann essay referenced by MDJAK. It has a plot of the 20D profile (Figure 3). It's huge, way bigger than Adobe RGB! :eek: It even exceeds Prophoto in a few spots.