Monitor Color Space vs. Photoshop Color Space

[Abitconfused]

If we photograph using Adobe RGB and output to a printer or file from Photoshop using Adobe RGB but our monitor displays "only" the sRGB color space, is the output then constrained to sRGB?

[dje]

If we photograph using Adobe RGB and output to a printer or file from Photoshop using Adobe RGB but our monitor displays "only" the sRGB color space, is the output then constrained to sRGB?

No the display color rendering is quite separate to the editing and output space.

Dave

[Abitconfused]

That's what I have believed also. But I am reading a Lightroom book by a very prestigious author who asserts that a print is constrained by the color space of the display.

[Manfred M]

That's what I have believed also. But I am reading a Lightroom book by a very prestigious author who asserts that a print is constrained by the color space of the display.

That is 100% garbage.

The print is constrained by the printer / paper / inkset properties and has nothing to do with the screen colour space.

The only issue is that the print and the screen might not show the same image if the gamut of the paper is wider than the screen gamut.

Your computer screen will be limited by its gamut, regardless of what colour space you are working in.

[george013]

That's what I have believed also. But I am reading a Lightroom book by a very prestigious author who asserts that a print is constrained by the color space of the display.

Always tricky to respond to something one thought to read. But I think it said something as: the result is constrained by the output device.
A digital image doesn't have colors, or sizes, or contrast or whatever. It contains digital values telling the output device at what power they should show these channels. Color managment is the traject that deals with the changing of those values so the output will be as true as possible.

George

[DanK]

+1 to what Manfred wrote. When you display on a monitor, one of two things happen: the software will either map to the color space of the monitor, or (in rare cases) it won't. Neither has any effect on a print because neither alters the data file. The only way a monitor would constrain a print is if you converted the image itself to sRGB to match the monitor.

[Manfred M]

That's what I have believed also. But I am reading a Lightroom book by a very prestigious author who asserts that a print is constrained by the color space of the display.

Who is the author and what book are you reading?

Assuming you are working with raw data, a colour space will be assigned when you create an image file. Just going from memory, I believe ProPhoto RGB can reproduce around 90% of the visible colours, Adobe RGB is around 65% of visible colours and sRGB can reproduce around 30% of visible colours. At a high level, the wider colour spaces can handle more saturated colours than the narrower ones.

When the colour is outside of the capabilities of the device, the computer will apply a rendering intent to take care of out of gamut (OOG) colours. For the computer screen, the OOG colours will be mapped to the hull of the colour space, i.e. taken to the closest value that is in gamut using the relative colorimetric rendering intent. As Dan pointed out, the data has not changed at all, just what the display hardware / software does with it.

Both Lightroom and Photoshop have a function called "soft proofing" which is used to emulate the gamut of the output device. While this is normally used in printing, it can also be used to show some of the things written about here.

In the following examples, I have used soft proofing to show how the different colour spaces can handle the colours in a very specific image I picked because I knew it would demonstrate this well. Note: the gray areas in soft proofing show the out of gamut colours for each of the colour spaces as well as the printer / paper combination I used.

Image 1 - ProPhoto RGB - everything appears to be in gamut.






Image 2 - Adobe RGB - we are starting to get some OOG areas






Image 3 - sRGB - a screen that is compliant with this colour space shows a lot of areas that are OOG






Image 4 - Soft Proof using Epson Stylus Pro 800 on Epson Glossy Photo Paper (glossy and luster papers will have a wider gamut than matte ones). Note that the printer / paper / ink set combination approach what the ProPhoto RGB colour space can reproduce, even though there are no ProPhoto capable computer screens. I did print this image on a luster paper and the emulation is quite close to what I see when I hold the print in my hands.





Just one more comment. This image has colours that fit quite nicely in the sRGB colour space - there are no OOG colours even in sRGB.

[Abitconfused]

OK, I read the applicable part of the book again and the author seems to be saying that when photographs use an sRGB monitor they make editing changes based upon sRGB information which then results in a less than optimal print. Whereas, if the photographer was using an Adobe RGB capable monitor better image editing choices would be apparent resulting in a higher quality print. Does this ring true?

[xpatUSA]

OK, I read the applicable part of the book again and the author seems to be saying that when photographs use an sRGB monitor they make editing changes based upon sRGB information which then results in a less than optimal print. Whereas, if the photographer was using an Adobe RGB capable monitor better image editing choices would be apparent resulting in a higher quality print. Does this ring true?

It rings true, Ed, but the "very prestigious" author is stating the obvious - by which I mean that if someone actually did edit for printing based upon the color appearance from an sRGB monitor, they would be acting out of ignorance and should not be surprised at less than optimum results (slight head-wobble).

[george013]

OK, I read the applicable part of the book again and the author seems to be saying that when photographs use an sRGB monitor they make editing changes based upon sRGB information which then results in a less than optimal print. Whereas, if the photographer was using an Adobe RGB capable monitor better image editing choices would be apparent resulting in a higher quality print. Does this ring true?

Besides what a "higher quality print" is,this is also depending on the gamut of the printer. It's easier to go from a wide gamut to a narrower, the other way is more difficult.

George

[DanK]

yes, it rings true in the sense that good printers have a wider gamut than sRGB, and editing based on sRGB doesn’t allow you to make use of that wider range of colors


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[george013]

yes, it rings true in the sense that good printers have a wider gamut than sRGB, and editing based on sRGB doesn’t allow you to make use of that wider range of colors


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To be sure. It's depending on the gamut of the printer.

George

[billtils]

This reminds me of discussions in the early days of "HD" monitors, when everyone said 1080 was so much better than 720, but forgot that it doesn't matter if the display is not calibrated correctly. So ... if anyone following this is an instructor and has access to a reasonable number of reasonably knowledgeable students could you please photograph something suitable with the camera set to Adobe and again with it set to sRGB, then process each identically for printing and print several copies of each. Code them and pass to the students and ask for their preferences.

If you wish and are able, you could also add another variable - don't print from Photoshop, use the printer manufactuer's S/W or print from another PP program.

I have no idea what the answer would be but it's what happens in the real world that counts ...

[Manfred M]

OK, I read the applicable part of the book again and the author seems to be saying that when photographs use an sRGB monitor they make editing changes based upon sRGB information which then results in a less than optimal print. Whereas, if the photographer was using an Adobe RGB capable monitor better image editing choices would be apparent resulting in a higher quality print. Does this ring true?

It seems to me that the author is likely not a particularly good or experienced printer. The part that he (oe she?) is forgetting about is that what we see on the screen is an additive colour, transmitted light, RGB image. A print is a subtractive colour, reflected light, CMYK product. What we see on the screen is at best an emulation of the printed image and if we want to judge. Even with soft proofing, we can probably get between 85% - 95% of the way there. In cases where we are dealing with image with a fairly limited colour range, it will be a the lower end of this and an image that has less vibrant colours will likely be at the higher end.

Any decent printer I know uses test prints to to fine tune his or her prints and does NOT rely on the screen to make calls on the colour. In general colour should be judged using lighting conditions that are close to those that the print will be displayed under.

An Adobe RGB compliant screen will certainly be better than an sRGB screen (in theory, for an image with colours outside of the sRGB range), but I do know a couple of master printers that use late model Apple hardware (100% sRGB compliant) screens to do their work. They also tend to use a fairly restricted set of papers and understand how they take up colours from their printers.

I generally do between 4 and 6 test prints before I "nail it" on a print. Problem images, I've done even more before I was happy. This makes perfect sense to me as that is how I did colour printing in the wet darkroom (lots of test prints).

[Manfred M]

To be sure. It's depending on the gamut of the printer.

George

A printer does not have a gamut. The gamut is a combination of both the printer (and ink set) AND the paper being used.

[Manfred M]

This reminds me of discussions in the early days of "HD" monitors, when everyone said 1080 was so much better than 720, but forgot that it doesn't matter if the display is not calibrated correctly. So ... if anyone following this is an instructor and has access to a reasonable number of reasonably knowledgeable students could you please photograph something suitable with the camera set to Adobe and again with it set to sRGB, then process each identically for printing and print several copies of each. Code them and pass to the students and ask for their preferences.

If you wish and are able, you could also add another variable - don't print from Photoshop, use the printer manufactuer's S/W or print from another PP program.

I have no idea what the answer would be but it's what happens in the real world that counts ...

Bill - we are getting into a whole wide ranging discussion here.

When it comes to printing, we have the same range of quality as we do in photography; anything from a selfie or snapshot right through to a high end commercial image or fine art photo. Printing goes much the same way; low end stuff where anything goes, middle of the road prints where the photographer has done a few of the basics to high end work that has many hours of work to get it right.

And yes, an experienced photographer / printer will pick up on something that has been well done right away. These subtleties are definitely something that one sees. It is much like when any of us look back into the archives and see work we did five or ten years ago and thought these were great images. Looking at them again, we see how much our work has improved. The same goes for printing; prints I thought were well done that I printed 7 or 8 years ago have a lot more flaws that I would care to admit and I can spot these right away.

The problem is that unless you print a lot, you simply will not see the subtleties between a mediocre print, a good print and a great print.

That brings me the the "real world" question that you ask and unfortunately the answer is that it depends on the knowledge and expertise of the person examining the print.

[george013]

A printer does not have a gamut. The gamut is a combination of both the printer (and ink set) AND the paper being used.

Mister Difficult, what does that change. The result is a print. Colors on a paper. And thus a gamut.
By the way, I'm quoting Dan's post.

George

[billtils]

... That brings me the the "real world" question that you ask and unfortunately the answer is that it depends on the knowledge and expertise of the person examining the print.

Manfred, I understand what you say in the part of your post not quoted here, but that was not my point.

If I recall correctly, you are a recognized judge (photographic, not law!) and if things are the same in Canada as they are here, step 1 in the assessis something along the lines of "do I like this image and why", followed by step 2, "how could it be improved". The real world issue addresses the first part - are there discernable differences that impact on the overall impression of the viewer? If the answer is "Yes" then that's that. If it is "No" then we go to the subtleties part, which is a perfectly valid but different matter.

(And I'm not sure that I agree with you that "subtleties" would be major factors in the difference between mediocre, good and great. Maybe between very good and great ...?).

[Manfred M]

If I recall correctly, you are a recognized judge (photographic, not law!) and if things are the same in Canada as they are here, step 1 in the assessis something along the lines of "do I like this image and why", followed by step 2, "how could it be improved". The real world issue addresses the first part - are there discernable differences that impact on the overall impression of the viewer? If the answer is "Yes" then that's that. If it is "No" then we go to the subtleties part, which is a perfectly valid but different matter.

Under CAPA (Canadian Association for Photographic Art) Standards images are judged on three separate criteria. The current approach to judging is to start with full points and to subtract 1/2 point for a minor flaw and a full point for a major flaw. The judging criteria are:

1. Was the image executed well from a technical standpoint. The main items considered are the use of colour, light, exposure, sharpness (or lack of sharpness) and overall photographic technique.

2. How has the photographer organized the elements in the image - are there distracting elements? How well was the space in the image used (which includes the effective use of negative space) and how well is the image composed?

3. What is the emotional impact on the viewer - Does the image create a strong mood? What is the emotional impact on the viewer? Does the subject matter make an emotional impact with the viewer? How imaginative was the photographers approach to the image?

As much as possible judges are trained to leave their own opinions at the door when judging an image, but that being said, that is not the easiest thing to do. A judge that has a phobia for insects is likely to view an image of an insect less favourably than one who is interested in them.

(And I'm not sure that I agree with you that "subtleties" would be major factors in the difference between mediocre, good and great. Maybe between very good and great ...?).

We are splitting hairs here, but I do understand where you are coming from. CAPA judging is generally done on a score of 1 -10. In general there are three judges looking at every image. I have seen a 5 point spread between the lowest and highest score assigned to a specific image. When there is a spread of 4 or more points in a score, the chair of the judging competition will stop the judging and will ask the judges to discuss their scoring. Sometimes they will change their score, but at other times they will not.

[Manfred M]

Mister Difficult, what does that change. The result is a print. Colors on a paper. And thus a gamut.
By the way, I'm quoting Dan's post.

George

George you continue to comment on aspects of photography that you have an incomplete knowledge of. When someone points out the errors in what you have said you come out and attack the response instead of learning about a subject that you have limited knowledge about. Normally when one quotes someone else's comments, we either put show a quote box or reference what they have written using quotation marks. Dan knows printing and does a fair bit of it. Do you have any significant experience in making photo quality ink jet prints?

There are a number of processes used to create high quality digital photographic prints; chromogenic, dye sublimation, digital offset and inkjet. For high quality prints, especially for people that do their own, the preferred process is an ink jet photo printer. The rest of the processes are largely confined to industrial scale operations with the exception of dye sublimation where both Canon and FujiFilm make small printers for home use.

There are two key variables that impact the gamut of a print. The printer (and associated ink set used) and the print medium (usually paper). Let's look at both of these to understand why one has to look at both of these when discussing the gamut of a print.

1. The printer - has a significant impact on gamut it can reproduce. Dye based inks tend to have a wider gamut than pigment based inks (but they bleed more and have a lower longevity than pigment based inks). The number of colours that a printer uses, generally defined as the number of ink cartridges also influence the gamut; more colours give a wider gamut. Consumer quality printers will deposit four colours (cyan, magenta, yellow and black) whereas higher end photo printers will have 6, 9 and up to 12 specific colour cartridges. People will use OEM (original equipment manufacturer) ink sets or might buy third party inks (for instance by using a continuous feed printer) which will produce a different gamut. A few other factors like dot size also play a role here.

2. Paper is the other variable. When we have a print, we are viewing it under reflected light conditions which is controlled by the print substrate quality and surface finish. In general, we print on paper, but other materials like metal, resin or canvas can also be used. Paper surfaces have different finishes. In general a matte paper scatters the reflected light more and will have a lower gamut than a lustre or glossy finish. The specific surface finish as well as paper components affect how the colours are reflected. The inclusion of optical brightening agents (OBA) affect the colour and quality of the light that is reflected and hence also the gamut.

If you look at any specific photo quality paper and photo quality ink jet printer, the paper manufacturer will provide specific ICC profiles which allow the printer or print software to adjust for paper characteristics and reproduce the colours in the image accurately. A print on a baryta paper with a lustre finish will have a totally different gamut than a rag based paper with a matte finish. This will be obvious to even a casual observer, not just an expert.