sRGB vs Adobe RGB for Canon 20D

[Jonathan Wienke]

The 20D's native sensor color space is larger than Adobe RGB; if you shoot RAW, you can take advantage of this.

[pminicucci]

Steve:
As Jonathan implies, shooting raw uses the sensor's complete color capabilities. Setting the 20D's color space to either sRGB or Adobe RBG is for JPEG files only and is not relevant to the raw capture.

Raw converters will move the linear raw file into whatever colorspace you select (that is supported by the converter, itself). On most, you can watch the RGB histogram to see what each possible colorspace is clipping in whatever color channels.

[Dinarius]

I'm not clear what is being recommended.

In the camera there is a choice of either sRGB or Adobe RGB.

There is no other option that I can see. So, are you saying that I should set it to sRGB?

Thanks.

D.

[Jack Flesher]

Whatever you set on the camera is only applied to jpeg images during in-camera conversion.  If you shoot in RAW mode and convert out of the camera, you choose the colorspace at that time and what you have set in the camera is ignored.

FTR I set my cameras to sRGB since when I shoot jpeg it saves me conversion time on the processing end. If I'm shooting jpegs the images are intended as snapshots -- and I don't care about maximizing colorspace for snapshot prints -- or web which cannot use the extra colors anyway.  In this fashion I save time by not having to convert the A-RGB images to sRGB later for web/email purposes.  

Lastly, to be entirely accurate the sensor in your camera does not see any color at all: It is applied during the de-bayering process.  However once converted that space is quite large,  essentially as large as Profoto-RGB which is a huge colorspace.

Cheers,
Jack

[Jack Flesher]

No, use Adobe Colour space. But this only applies, in camera, if you are shooting JPEG.

Thanks.

I process using DPP.

In Tools/Preferences/Colour management should I set the Default settings of Work colour space to sRGB, Adobe RGB or Wide Gamut RGB?

D

If you follow that advice, make darn sure you convert to sRGB before posting on the web or emailing, or your images will look like crap.

[Jack Flesher]

So, I take it from what you are saying that if I am burning to CD, which I tend to do, I should stick with Adobe RGB?

D.

It depends on how your images are going to be viewed...

If they are going to be viewed in a "color-space aware" program like Photoshop, then A-RGB is fine.  Moreover, if you are going to print them, most ink-jet printer color-spaces closely match that of A-RGB, so it is a preferred color-space to print from.

However, web browsers can only "see" sRGB -- A-RGB contans colors that fall outside of web vision, and therefor just get dropped out, leaving your image without about 25% of its original colors.  This will in turn make these images look "flat".  Hence the A-RGB image must first be CONVERTED TO (not assigned) sRGB for proper web view.

[Ray]

Any comments on the issue of A-RGB yellow versus PP-RGB yellow? I'm using Bill Atkinson profiles with the Epson 7600.

[steve45]

I know the 20D will convert the raw file to either sRGB or Adobe RGB, but I am interested if any one has seen the colour space for the sensor itself?
Cheers
Steve

[kaelaria]

The sensor space is larger than both.  aRBG is larger than sRGB, so it's the best you can do.

[steve45]

Thankyou folks.
That is exactly what I was after.
Cheers
Steve

[DaveLon]

No, use Adobe Colour space. But this only applies, in camera, if you are shooting JPEG.

Dave

[Ray]

I convert into ProPhoto RGB with ACR. I used to think Adobe RGB might be a better match for my printer's gamut, then one day I had problems with my Epson 7600 due to lack of use. Couldn't get a proper yellow despite repeated cleaning cycles. It was more like pea green. So I smashed open the yellow cartridge which was almost due for replacement anyway, and lightly painted some ink on a sample of lustre paper I was using at the time. After I'd fixed the problem with a series of power cleaning routines and things were back to normal, I discovered Adobe RGB could not produce a pure yellow (never had) whereas ProPhoto RGB could, or at least came closer to my sample of pure yellow pigment.

I don't expect there would be many images that would require that pure yellow, but you never know  

[Dinarius]

No, use Adobe Colour space. But this only applies, in camera, if you are shooting JPEG.

Thanks.

I process using DPP.

In Tools/Preferences/Colour management should I set the Default settings of Work colour space to sRGB, Adobe RGB or Wide Gamut RGB?

D

[Dinarius]

So, I take it from what you are saying that if I am burning to CD, which I tend to do, I should stick with Adobe RGB?

D.

[pminicucci]

Dinarius:

Here is what Ethan Hansen posted back to me regarding Wide Gamut RGB:

Wide Gamut is a slightly smaller color space than Pro Photo RGB. PP RGB was designed to contain every color E6 film can record. Wide Gamut truncates this range slightly, but has more sane RGB primaries. Wide Gamut has the additional advantage of being a gamma 2.2. space with a 6500K whitepoint. In practical terms, it doesn't really matter which one you use.

(Ethan runs Dry Creek Photo and I expect qualifies as an expert on color management.)

Separate from the definition of what the space actually is, is the conversation about what space you should use for work. As Jack and others have pointed out, most of today's ink jet printers max-out on color gamut somehere short of Adobe RGB, depending on paper. And, as Jack also points out, images purposed for the Web cannot use more than sRGB. However, printer gamuts are getting bigger. I've read reports that the Epson 4000 actually exceeds the Adobe RGB space, at least in cyan.

So the issue is one of what archival status do you want for your work. If you convert to Adobe RGB (from raw), you are throwing away color information that may be "printable" in next generation printers. While you can convert again, in a larger color space, you would have to rebuild the file from scratch. If you convert to the widest possible space (ProPhoto or Wide Gamut RGB) you have more color information than the present crop of printers can handle and you have to tweak any out-of-gamut colors. To some extent, it is pick your poison.

Personally, I now use ProPhoto as my working space and convert to Adobe RGB on a print-only file copy if necessary. For any Web or multimedia viewing, I convert to sRGB as Jack already noted.

[Dinarius]

So the issue is one of what archival status do you want for your work. If you convert to Adobe RGB (from raw), you are throwing away color information that may be "printable" in next generation printers. While you can convert again, in a larger color space, you would have to rebuild the file from scratch. If you convert to the widest possible space (ProPhoto or Wide Gamut RGB) you have more color information than the present crop of printers can handle and you have to tweak any out-of-gamut colors. To some extent, it is pick your poison.

Personally, I now use ProPhoto as my working space and convert to Adobe RGB on a print-only file copy if necessary. For any Web or multimedia viewing, I convert to sRGB as Jack already noted.

Phew!

Thanks guys. A lot to digest.

All my work involves passing on images via CD to designers for printing. I don't even own a printer, so no issue there. Also, web is not an issue for me.

On balance, I take it from what you are saying that I should convert into Wide Gamut in DPP and not Adobe RGB?

Secondly, you mention Pro Photo as being slightly bigger again than Wide Gamut. Pro Photo is not an option in DPP. What program does it come with?

Thanks for all the help.

D.