Need Help in Understanding Colour Rendering

[shootme]

I can set on my camera the colour choice of sRGB or Adobe RGB does either make a difference when printing? For me it seems I get a better colour rendition when printing when the camera is set to sRGB rather than Adobe RGB? Some clarity around this would be helpful and how this interacts (or doesn't) with printer settings, thanks, S

[freygr]

The color mode makes no difference as long as the display and printer drivers are set to the same setting. Now if there are set to different color spaces then you will never get the color balance correct. The color balance is main reason for the color calibration programs.

[another view]

If you're not doing your own printing, you probably want to stick to sRGB. Printing in the wrong color space (such as an Adobe RGB file printed in sRGB) will make the colors "off" by a fair amount, and most labs will only print in that color space (always used to be true, but I haven't checked it out in awhile). Adobe RGB has its fans, but I've stayed with sRGB and not felt like I was missing anything.

[shootme]

AV I think you are right, I've switched back to sRGB, thanks for the input. S

[Medley]

I wouldn't, but that's just me. If you have Photoshop, click on the color-picker. Now check the "only Web Colors" box. THAT"S sRGB. The colors you see are the colors you're limiting your photographs to.

Now check the "only Web Colors" box again, to turn it off. THAT'S Adobe RGB, and it has a much greater range of colors. In techno-geek terms, it's a 'larger' color space.

The question is, which set of colors would you rather use to create your images? To me, Adobe RGB seems that it would give a much truer color rendering. Therefor, I shoot almost exclusively in Adobe RGB.

Can this cause color shifts? You betcha! You see, the printer uses neither sRGB OR Adobe RGB. It uses a color space called CMYK. CMYK stands for Cyan, Magenta, Yellow and Black. Sound familiar? Those are the ink cartridges in most printers.

So at some point, BOTH sRGB and Adobe RGB are going to have to be converted to CMYK to print. But here's the deal: when switching from a smaller color space to a larger one, color shifts are seldom necessary, because the larger color space can already duplicate most, if not all, of the colors of the smaller color space. But the exact opposite is true when converting from a larger color space to a smaller one- some colors will need to be converted to fit into the smaller space.

See, that's the reason you don't get color shifts in sRGB. You've already limited yourself to such a small amount of colors that CMYK doesn't NEED to change them. It can already reproduce all those colors and more! But Adobe RGB is a larger color space than CMYK, and contains many possibilities that CMYK can't reproduce. So at some point, those colors need to be changed into something that CMYK CAN reproduce.

So saying that you use sRGB to eliminate color shifts is kind of like saying you don't shoot in Raw mode because the printer won't print 16 bit images. Yes, a conversion will be necessary, but most image processors give you the tools you need to take charge of that conversion and do it in a way that allows you to control the process without sacrificing color quality.

- Joe U.

[shootme]

Joe, good explanation, it explains why when I printed I didn't get the colour rendering I usually do. I had switched to Adobe RGB because of what I had heard and read that it was better for colour rendering. If I was to send a photo to a professional printer would it be better than to have the photo taken with Adobe RGB (and yes I use Photoshop CS4). I might check with the local photo shop and see what they say/advise. Stay tuned. Cheers S

[OldClicker]

Mpix asks for sRGB. - TF

[Medley]

Which is precisely why I don't use Mpix TF. Don't get me wrong- I understand exactly WHY a printing business would ask for sRGB. It makes good business sense. No color shifts mean no unhappy customers. Can't you just hear it? "You screwed up my prints! They were fine when I sent them to you, and now the colors are all wrong!"

Think about it TF. Some of the members of this forum didn't understand why the color shift was happening, and most of the members here are more knowledgeable than the average shooter. I guarantee you that the average shooter is Mpix's target market, because that's where most of the money is. So why NOT make things as foolproof as possible?

Fortunately, I try never to let business decisions get in the way of my photography. My concern is the highest quality color rendering I can achieve- not the business model of the print shop.

shootme, to answer your question, here is my file format preference for farmed out prints:

1) the printer's downloaded icc color profile, if available
2) CMYK
3) Adobe RGB

The icc profile is really nothing more than a very specific CMYK format, tuned to the specific printer that will be printing your images. A CMYK format is best for printing because you can convert the image early on, before doing any color correction. That way, when you DO those corrections, the results will still be printable without color shifts, because your still using the same color space the printer uses. So you can not only take a lot more control over the conversion from Adobe RGB to CMYK, but you can edit the colors IN CMYK after the conversion takes place.

Does that make sense?

IF I absolutely MUST submit images in Adobe RGB, then I essentially do the above, but switch back to Adobe RGB when I'm done. Remember, Adobe RGB is the larger color space, so no color shifts ( or loss of information) should take place when reverting to that format. And since the colors are all compatable with CMYK, there should be no color shifts when printing.

- Joe U.

[shootme]

Joe, thanks again I'm getting a great education here, the more time I spend with my favorite hobby the more precise I want things to be and the more knowledgeable I want to be to ensure I get the most out of what I'm doing. I don't print that much but when I do it has to be the best it can be with the possibilities I have at my disposal. Cheers, Peter

[shootme]

Feedback from the printing shop for what it's worth. Adobe RGB better as it has a wider colour space. That said if publishing just for Internet sRGB if printing on your home computer sRGB unless you want to tweak the setting, bump up colour levels (i.e. via vivid control) the Adobe RGB can give great results. For the print shop they can do more with it if you use Adobe RGB. Shootme

[Anbesol]

AdobeRGB has much better reds and greens, SRGB has better blues. Try taking a picture of a bright green plant, then take a picture of the bright blue sky, almost every time you will immediately notice a much more pleasing look in the corresponding profiles. That said, I prefer AdobeRGB's colorspace, but find that sRGB is a much more convenient and easy profile to work in. I use them both, I mainly stick with sRGB just for the convevience, but use adobeRGB for all other shots. Course - if you use Raw, you don't have to pick one over the other.

[Medley]

Feedback from the printing shop for what it's worth. Adobe RGB better as it has a wider colour space. That said if publishing just for Internet sRGB if printing on your home computer sRGB unless you want to tweak the setting, bump up colour levels (i.e. via vivid control) the Adobe RGB can give great results. For the print shop they can do more with it if you use Adobe RGB. Shootme

Yeah, about the only time I can get away with submitting in CMYK is for magazine publishers and such. That's why I use printers that have a downloadable icc printer profile. It lets you switch to the exact set of colors the printer uses, before you make any edits. Then there can be no color shift.

- Joe U.

[Skyman]

The other side of the coin is what your computer monitor is doing as this affects how you adjust your pictures colour and this will most likely be different from how you print the photos. Having a calibrated monitor will help you a lot, either with adobes built in calibration or with a third party calibration tool such as a spider. Monitors use an RGB colour space as they are mixing wavelengths of projected light where as it said earlier printers use a CMYK colour space as they are mixing absorbtion rates in inks. The colour from an in comes from what light the ink absorbes rather than what light it creates as opposed to the light that is projected from a screen. If your lab is kind enough to give you the icc profiles for its printers you can calibrate your monitor to display them very accurately. For most people simply calibrating their monitor is good enough. Some of the more advanced calibration tools can calibrate your monitor and your printer so your results will be very accurate. either way it is all about developing a workflow that suits you. Many people will opt for RAW and adobe RGB simply because they have been told that is the best way. Others will use sRGB as it gives them a consistency for very little effort. The colour rendering software that drives most printers and screens is good enough that only the practiced eye would notice the difference (unless perhaps you held the print up to the screen) The choice is always personal but i comes down to a mix of Accuracy, Vibrancy, Consistancy and Time. Incidentally in theory using one of the better brands of printers with photo papers and inks is supposed to give an archival life superior to a chemical print from a lab, so other than cost printing at home is a great option if you want to control your prints more, especially as effective colour calibration is more affordable than it was a few years ago.