Adobe RGB or sRGB?

[Scorpion]

Digital SLRs and Raw converters offer a choice of sRGB or Adobe RGB as an output colour space. Adobe RGB having wider colour gamut than sRGB may lead some to assume Adobe RGB is the better choice.

This may be correct if you make your own prints and follow a colour-managed workflow through to the printed output.

For display on a Monitor, Projector, or the Internet which is what PicturesToExe is all about, then sRGB is a better choice.

Not my advice, I don't claim to be qualified, but gleaned from the web site of Ken Rockwell who is. http://www.kenrockwell.com

If you would like to know more visit the site, do a search on sRGB, then follow his reasoning.

Incidentally the site is a mine of information on all things photographic, an entertaining read, well worth a visit.

[davegee]

Scorpion,

Good advice.

All that's necessary to prove the point is the put two jpegs from the same source image into a PTE show - firstly in RGB mode and then after converting the profile to sRGB (or vice versa).

DaveG

[lathompson]

I'm no expert, however I'm going to stick my 2 cents into this. I think as long as you don't make a photographic print on paper, the difference is going to be negligible to most eyes. After all, our computers and television monitor settings are less than perfect without a lot of tweaking with specialized software and hardware involved. And even if we are tweaked to perfection, it would be likely that every time the show is seen on a different monitor or projected, you are going to get something slightly different.

Where the setting is most important, is when you prepare an image for making a paper print using the Adobe RGB color space and the printing machine that prints it is optimized for sRGB images. There is a very large difference in this case. I recently found this out when an assistant changed my Photoshop settings. The images looked great on the monitor, but printed with very blue skin tones. As I said, I'm not a calibration expert, I'm simply passing on an experience. sRGB is a much better choice. In this case, I'm talking regular photographic prints, not inkjet or offset printing. That's a completely different subject and I definitely know nothing about those!

larry

[Maureen]

Ken Rockwell's article http://www.kenrockwell.com/tech/adobe-rgb.htm

This subject is not as simple as just choosing one or the other.

I feel there is a better explanation given at

http://www.cambridgeincolour.com/tutorials...dobeRGB1998.htm

with clearer gamut diagrams.

Lots of Photoshop books also cover this topic in greater depth.

As someone who works with prints and projected images,

I usually use the old general rule of deciding if the images are for

AV work = projecting = set camera to sRGB

prints = set camera for RGB

Convert the image in Photoshop if necessary.

Worked so far for me, my work has been projected across different monitors, big screens, etc in many different venues and countries without problems, and printing has been consistant without colour problems and good enough for International Salons, etc

Often calibration is a far more important issue.

[kessi]

Hi Maureen,

I read your post with interest. I am part of a tiny photographic club and I often do short presentations using Pic2Exe. One of the factors I find incredibly frustrating is calibration of the LCD monitor and the projector. I have been to so many sites to look at HOW To's, but just cannot get it right. I know one can use instruments like Spyder, etc, but the price is quite heavy. Are there any hints or tips you could possibly have on calibration of monitors. I'm sorry if this is not the correct forum to ask this question, but I have been reading a lot of your comments and thought you might be able to help.

Kind regards,

Irmgard Kaiser

[fh1805]

For what it might be worth, I show PTE sequences to audiences several time each month and have NEVER calibrated any of my equipment. My camera is set to sRGB, my PC is set to sRGB, my projector is set to sRGB. What I see on my LCD monitor looks like what I saw before I pressed the shutter release. What I see projected on the screen looks like what I saw on the monitor.

As far as I am concerned, if it looks right, then it is right. Nobody has ever commented on any colour bias in my projected images - and at least one audience each month is a camera club or photography club. I have posted some of my sequences to this and other forums and nobody has commented adversely about the colour rendition.

In the days when images were digitised by scanning from slide or film and so could have come from different emulsions I suspect that calibration might have been essential. But today, where I suspect most users are uploading from either a single camera or from mutiple bodies from the same manufacturer, then I suspect the need for calibration is lower.

I also suspect that the need for calibration is lower when using LCD technology comapred to the old CRT monitors.

I may be wrong in all that so I'll watch with interest as this discussion develops.

regards,

Peter

[Maureen]

I have opened a new thread about hints and tips on calibration.

Hopefully many can add advice for Kessi and others on this topic.

Best Wishes

Maureen

[davegee]

I agree with what Peter said 100% and would ADD just one thing:

IF you normally shoot in RGB then CONVERTING THE PROFILE to sRGB is ESSENTIAL when the images are used in PTE.

You have to try a side by side comparison to judge for your self.

DaveG

[Peter S]

Colour calibration of monitors is in my view absolutely essential if you want to see colours consistently.

I have two monitors sitting next to one another. Before the second monitor was calibrated it displayed colours that were significantly different from those on the first monitor.

If you view images at different times in different lighting conditions you may well think that they were the same but try the side by side test and you are likely to get a surprise.

It is somewhat difficult to compare a print with a screen image but before I knew anything about colour management I was shocked to see how different the colours on my prints were from those on screen. Calibrating my screen with a Spyder made a great improvement. At least I can be fairly confident now that my print will be very close to what I intended.

AdobeRGB or sRGB? What about ProPhoto RGB?

If you shoot RAW and if you use Lightroom you will be working in ProPhoto RGB. You can however export a file in any of these colour spaces. If you do this and view them in Lightroom the colours look pretty much identical. If you look at them in PTE the ProPhoto versions will look much less colourful. The Adobe and sRGB versions may not look much different but they will not be identical.

So why would you want to use ProPhoto? If you want to make changes to your image it is best to start with the maximum amount of information and a wide colour space. That means RAW files and ProPhoto. When you have completed all your manipulations then you can change to sRGB to use the image in PTE.

Older and cheaper monitors show a narrower range of colours than newer and more expensive (wide gamut) monitors so you may gain little by using the widest gamut available but printing is a different issue.

Adobe has an intersting paper at:

http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf

As Maureen points out many Photoshop books provide information on this topic. There are also specialist books on colour management.

If you only shoot in RAW it makes no difference whether you set your camera to sRGB or AdobeRGB.

Kind regards

Peter

[Ken Cox]

buy a macbeth colour card

go to the macbeth site -- i have posted the url elsewhere

does your colour card match the sample of the colour card

when you go on a shoot place the macbeth colour card in a position that will be representative of the lighting and take a picture or several if you want to take them under variuos settings

compare the results to your colour card vs what is on the monitor

ken

[davegee]

With the greatest respect, I fear that Peter S is missing the point here.

We are (most of us anyway) here because we are interested in AV and not because we are printers.

My experience and my eyes tell me that when I use sRGB images in PTE they look richer and display more depth and look correct when displayed alongside the eqivalent RGB images.

The test I advise is:

Take an image shot in RGB in-camera and put it through your system making sure that the colour mode/profile is not changed by your RAW converter or Photoshop/Lightroom (whatever) without your knowledge.

Save a JPEG without changing the profile as version 1.

Change the profile to sRGB and save a JPEG as version 2.

Now display both images side by side in a PTE show in Preview.

The sRGB version is going to be the "correct" version showing more depth and saturation.

A shot taken at the same time in the same lighting conditions as the previous (RGB) version but this time in sRGB and put through an sRGB process (RAW converter / PS / Lightroom etc) is going to look exactly like the version 2 image without the hassle of having to change its colour mode before saving as a JPEG.

By all means have your monitor(s) correctly calibrated but that is not relevant to the RGB/sRGB discussion in PTE.

Peter's point about ProPhoto is an interesting one, but since my camera does not offer that colour space I don't see how it fits into this discussion. It seems to be something which, once again, printers need to consider and not something which we need for AV.

If I want prints from my sRGB images I simply change the colour profile to Fuji_DP2_ProAm, change the resolution to 402 ppi at the size I want, whack them onto a CD, send the CD to ProAm and within a couple of days I get perfect prints delivered to my door at a price I can afford. (And they look exactly the same as my on-screen versions).

Best wishes,

DaveG

[Peter S]

No Dave I have not missed the point!

I agree that you should save all your images in sRGB for use in PTE. If you want simplicity set your camera to jpeg and sRGB and do no manipulation other than cropping.

BUT.... If you want to manipulate your images in Lightroom and/or Photoshop you will achieve the best results by shooting in RAW. If you shoot in RAW it is IRRELEVANT what setting you use on your camera for colour space.

Colour gradation, amongst other things, is much better if you use RAW and manipulate images in a colour space larger than sRGB whatever you use as a presentation medium.

Kind Regards

Peter

[davegee]

Peter,

I shoot exclusively in RAW and my workflow includes Nikon NX2 and Photoshop.

I do not believe that it is irrelevant what colour space you shoot in if you shoot in RAW (it is included in the Metadata). If it were irrelevant the logical thing would be that the option to change from RGB to sRGB would not be available in the camera menu when RAW is set?

I have never experienced any colour gradation problems when editing 16 Bit NEF files shot in sRGB and processed in sRGB throughout whether for PTE or for printing.

Best wishes,

DaveG

[keffs]

....I do not believe that it is irrelevant what colour space you shoot in if you shoot in RAW (it is included in the Metadata). If it were irrelevant the logical thing would be that the option to change from RGB to sRGB would not be available in the camera menu when RAW is set?....

Sorry, if you shoot RAW, the colour space is irrelevant. That is the whole point of RAW. The data, straight of the sensor with no onboard manipulation. Choosing colour space can still make a lot of sense, for example with simulataneous capture of RAW and jpg.

In general, unless a monitor is adjusted "correctly" and the viewing application supports ICM colour management then colour control is hit and miss.

Steve