Color spaces: processing, exporting, printing

[xpatUSA]

How long [do] you think monitors with only sRGB will be manufactured? I just recommend that everyone keep their files and PP efforts in a colour space that is reasonably future proof.

+1 to that recommendation.

As a Sigma camera user (SD9 to SD14) it is better for me to keep the raw X3F files. Thus they remain in camera space for which the term "color space" is less appropriate.

Some camera raw values can actually be out of ProPhoto's gamut !! (As are some cyan shades in the CIE color model, BTW). In other words, even the mighty ProPhoto does not encompass all visible colors, in spite of claims to the contrary.

Importantly, in Sigma's converter, the development adjustments can be saved embedded in the raw file, without affecting the original parameters such as white balance. The original parameters can be restored, if necessary.

As to lack of future support, there are many third-party converters for my early X3F files (pre-SD15) including good old Dave Coffins' open-source DCraw. And a typical X3F file is 6Mb whereas a 16-bpc TIFF made from it is 19Mb. No contest.

Not a exhortation to buy Sigma who have next to no third-party support for their latest creations (Merrill & Quattro) and whose converter runs like molasses for those files.

[ajohnw]

+1 to that recommendation.

As a Sigma camera user (SD9 to SD14) it is better for me to keep the raw X3F files. Thus they remain in camera space for which the term "color space" is less appropriate.

Some camera raw values can actually be out of ProPhoto's gamut !! (As are some cyan shades in the CIE color model, BTW). In other words, even the mighty ProPhoto does not encompass all visible colors, in spite of claims to the contrary.

Importantly, in Sigma's converter, the development adjustments can be saved embedded in the raw file, without affecting the original parameters such as white balance. The original parameters can be restored, if necessary.

As to lack of future support, there are many third-party converters for my early X3F files (pre-SD15) including good old Dave Coffins' open-source DCraw. And a typical X3F file is 6Mb whereas a 16-bpc TIFF made from it is 19Mb. No contest.

Not a exhortation to buy Sigma who have next to no third-party support for their latest creations (Merrill & Quattro) and whose converter runs like molasses for those files.

Conservators seem to prefer tiff image files Ted - last time I looked. There are views expressed on that aspect in various august places on the web. DNG make some sense too - if Adobe is about and probably if not too but doesn't include any processing the "artist" may have applied. Sidecar processing files might not be supported over time.

There are all sorts of problems about gamuts not least of which is 3 colour mixing as in prophoto for instance some aren't colours at all so wont be seen by us even if they were mixed. Then there is the eyes sensitivity curve against colour. This generally means putting out higher levels of blue than we see in nature. There are also huge gamuts about that use 3 real colours. I'd guess that there is a problem producing them but have no idea. TV and film people seem to be more interested in that area

I feel any improvements need a step change - just as true colour was and the culprits who do it might be the same. The HP MS memo on including gamma correction to fix it used to be kicking about on the web.

Jpg's move on with more to come

https://en.wikipedia.org/wiki/JPEG

What style of jpg that can be loaded into an application is entirely dependent on the software used. They are already tagged.

Other things kicking about and probably active

https://en.wikipedia.org/wiki/JPEG_XR

Some might notice the reason that is supposed to have kicked jpg off as a standard - free software. Bit of a simplistic view in my opinion other than it saved some areas a lot of work.

John
-

[xpatUSA]

Conservators seem to prefer tiff image files Ted - last time I looked. There are views expressed on that aspect in various august places on the web. DNG make some sense too - if Adobe is about and probably if not too but doesn't include any processing the "artist" may have applied.

Yes, those are indeed the standard views, however not shared by me as a Sigma user. As to DNG, Adobe's raw-to-DNG converter does an inferior job with X3Fs, compared to Sigma Photo Pro. I've tested DNG in the past and have been roundly trounced elsewhere for suggesting that DNG is even 'good enough' for X3Fs.

The kicker for me is that both TIFF and DNG formats are controlled by Adobe a.k.a. the elephant in the room; whereas sRGB, ProPhoto and JPEG are not

Sidecar processing files might not be supported over time.

Sigma doesn't use side-car files.

There are also huge gamuts about that use 3 real colours.

<>

I didn't fully understand that, especially "3 real colors", could you expound a bit, perhaps with examples or illustrations? Ta!

[ajohnw]

Yes, those are indeed the standard views, however not shared by me as a Sigma user. As to DNG, Adobe's raw-to-DNG converter does an inferior job with X3Fs, compared to Sigma Photo Pro. I've tested DNG in the past and have been roundly trounced elsewhere for suggesting that DNG is even 'good enough' for X3Fs.

The kicker for me is that both TIFF and DNG formats are controlled by Adobe a.k.a. the elephant in the room; whereas sRGB, ProPhoto and JPEG are not



Sigma doesn't use side-car files.



I didn't fully understand that, especially "3 real colors", could you expound a bit, perhaps with examples or illustrations? Ta!

I did try to do just that Ted but failed. There is one gamut where all 3 colours are within the span of human vision and the green point is more central than others. One I have found is rec 2020 which I believe is bigger than aRGB but the points made concerning bit depth here are pertinent.

http://wolfcrow.com/blog/say-hello-t...of-the-future/

All 3 colours used are real. Where as ProPhoto's aren't.


https://en.wikipedia.org/wiki/ProPhoto_RGB_color_space

The "green" and blue points are outside of what is reckoned to be the span of human vision.

The one I can't find puts green near to 520nm.

The other aspect of rec2020 is that it scarcely moves the blue from current positions.and avoids going into areas that our eyes are not very sensitive to. Enormous levels of what is really near UV would have to be emitted if it did. Too much blue is known to cause eye problems.

John
-

[ajohnw]

Here is one but not the similar one I was looking for.

https://en.wikipedia.org/wiki/Wide-g...GB_color_space

The choice of the blue probably makes it unfeasible.

Go far into the red and people could cook there toast on it - maybe that is why prophoto doesn't.

John
-

[xpatUSA]

I did try to do just that Ted but failed. There is one gamut where all 3 colours are within the span of human vision and the green point is more central than others.

All 3 colours used are real. Where as ProPhoto's aren't.

Thanks, that's what I was looking for. Here's one which also shows "Adobe Wide Gamut" and, for interest, a Real World gamut:



Drifting further off-topic, you'll know that the CEI xyY diagram exaggerates greens a bit and, when we look at Adobe RGB (1998) in the L*a*b* or the L*uv models, it ain't as big as wot people fink it is

[ajohnw]

My calibration software shows the gamut in several forms so yes I am aware that the size and shapes change. Also that a 3D map is really needed to really show them. That can show that colours go out of gamut as the go "up" too. One of the features used to show how wonderful so called prophoto printing is. I'd like to see these imaginary bottles of ink.

I don't all together hold with real world gamuts or pointers. Who ever comes up with them has bias - something to prove - what ever it is that they think..

I can't see things changing much other than if it is a fairly large jump such as REC-2020 appears to be.

John
-

[pnodrog]

t doesn't confuse me at all - just others including you by the sound of it.

I only output sRGB images so am well aware of the fact that aRGB images can look different when colour managed into sRGB.in a browser as they are posted at times. If I printed images myself, or at all I would be aRGB capable. ------


John
-

John you seem to be preoccupied with the difference between sRGB and aRGB. Most people on this site will not be confused and are already fully aware of the differences between sRGB and aRGB. However if you carefully read what I have written nowhere do I even refer to aRGB and it was not the point of my post.

I actually have more productive things to do now than to make any further response.

[ajohnw]

John you seem to be preoccupied with the difference between sRGB and aRGB. Most people on this site will not be confused and are already fully aware of the differences between sRGB and aRGB. However if you carefully read what I have written nowhere do I even refer to aRGB and it was not the point of my post.

I actually have more productive things to do now than to make any further response.

Maybe you should spend more time answering questions from people who don't understand the basics of what is going on in some PP packages under the surface. Also people who find this answer helpful which in real terms is just a snide comment aimed at me on the face of it.

John
-

[pat3pee]

Mark,

I have watched a you-tube video by X-RITE Photo (attached below ) and in the latter part of the video there is quite a good explanation to your question of using different color spaces. Below is a screen shot of how the aRGB and sRGB show up over the internet and another of this person's preferred work flow.





I hope this helps. I have myself mistakenly sent aRGB photos to the internet for years


https://www.youtube.com/watch?v=gfSVv-f0h70

[xpatUSA]

. . . I have myself mistakenly sent aRGB photos to the internet for years

Not to worry. As we all know, most apps are 'color-managed' these days. Curiously though, the catalog function on Sigma's proprietary Photo Pro converter (SPP) has yet to catch up with the rest of the imaging world:



Interesting to compare:

The sRGB image looks OK. The Adobe a little washed out in the yellows. The ProPhoto less saturated and a bit darker. The Apple also darker. (darker because each of those two have gamma = 1.8).

This comparison is posted just for information - not for responses telling me why they look different ;-)

P.S. I never use Adobe RGB (1998) a.k.a. 'aRGB' . . . . a) it's another Adobe bastard child, like it's cousin 'Melissa'. Rumor has it that sRGB was a mistake - someone got the red and blue but the green was mistakenly taken from a different space. b) it has less color resolution in JPEG. c)it's Adobe

Even if I bought a fancy monitor or a real printer, I wouldn't use it.

rant over.

[Downrigger]

Yes - that's a pretty helpfully done, basic treatment. Thanks. One needs to see this different ways over a period of time to acquire some "bit depth" in comprehension.

Here's another twist on the question, though. When I am editing in Lightroom (in whatever AdobeRGB-ish space it is) and take the image to NIK's Viveza I have the option to work there in ProPhoto, aRGB, or sRGB. I used to do my NIK editing in ProPhoto, 16-bit but now do not see the sense in it and guess that I should simply work in aRGB, 16-bit from which I can get 16-Bit TIFF. That can be used for some printing (depends on printer/lab) but for the web should get dumbed down to sRGB/8bit.

On a slightly different note, with respect to the use of a color checker as illustrated in that nice video, I am surprised that more of the on-line ed for Lightroom doesn't put the color management issue/camera calibration more prominently in the basic educational modules. Maybe they do not want to scare folks off. I am impressed that a lot of the processing and posting work I have been doing over the past couple years of learning this hobby has missed the boat with respect to pretty fundamental steps to obtaining the best color results.

[Downrigger]

P.S. I never use Adobe RGB (1998) a.k.a. 'aRGB'. a) it's another Adobe bastard child, like it's cousin 'Melissa'.

Not sure what you mean by "use" - do you mean "use for export for any purpose"? I can get that. But for those of us processing in LR, we all have to "use" aRGB, I think, because I understand that some version of aRGB is the space Lightroom uses to show us our images as we mess with them.

[davidedric]

Hi Mark,

Actually, Lightroom's internal colour space is proprietary but I understand is close to ProPhotoRGB.

Dave

[xpatUSA]

Not sure what you mean by "use" - do you mean "use for export for any purpose"? I can get that.

Yes, as in never for any purpose.

But for those of us processing in LR, we all have to "use" aRGB, I think, because I understand that some version of aRGB is the space Lightroom uses to show us our images as we mess with them.

Not too sure about that, Mark, although I have been a dedicated non-user of LR since it first came out

Other experts here will know. If you're referring to LR's working space in the Development module, you might be thinking of Adobe's "Melissa", which is a weird version of ProPhoto, named after a lady development engineer, so the story goes.

[ajohnw]

Mark,

I have watched a you-tube video by X-RITE Photo (attached below ) and in the latter part of the video there is quite a good explanation to your question of using different color spaces. Below is a screen shot of how the aRGB and sRGB show up over the internet and another of this person's preferred work flow.





I hope this helps. I have myself mistakenly sent aRGB photos to the internet for years


https://www.youtube.com/watch?v=gfSVv-f0h70

I think that is a touch out of date in as much as browsers are mostly colour managed now so will try to convert. The amount of difference varies. Sometimes it's hardly noticeable but as several things vary they are still different.

John
-

[pnodrog]

Maybe you should spend more time answering questions from people who don't understand the basics of what is going on in some PP packages under the surface. Also people who find this answer helpful which in real terms is just a snide comment aimed at me on the face of it.

John
-

Sorry John saying preoccupied was a little unfair - just a response to one of your comments.

In essence I think we agree but are just putting a different emphasis on the present vs the future (very near future).

To sum up:-

1. At present sRGB is the only colour space that for most people provides a WYSIWYG (what you see is what you get) environment.

2. If you move from a larger colour space to sRGB there will be shifts in some colours. Colour management only tries to make these shifts acceptable depending on intent, it cannot completely solve the problem.

3. As sRGB is a restricted colour space it is prudent to keep your "master version" either as RAW or in the widest colour space available.

4. The work flow to best achieve a suitable outcome will depend on software, hardware, the intended use and type of photography.

[Macmahon]

[QUOTE=Downrigger;465362 When I am editing in Lightroom (in whatever AdobeRGB-ish space it is) and take the image to NIK's Viveza I have the option to work there in ProPhoto, aRGB, or sRGB. I used to do my NIK editing in ProPhoto, 16-bit but now do not see the sense in it and guess that I should simply work in aRGB, 16-bit from which I can get 16-Bit TIFF. That can be used for some printing (depends on printer/lab) but for the web should get dumbed down to sRGB/8bit.
[/QUOTE]

Mark

FWIW I always edit in ProPhoto as working colour space when using a Lightroom Plugin, be it Viveza, Silver Efex, or Photoshop CC to avoid unnecessarily clipping colours in editing. I am happy and confident that the conversion
from working space to output space (whether it be my monitor's space, sRGB for web, or my printer's output colour space) will be accurate and give me the best colour output that my chosen output device (is the web a device?) can support.

You might find this web site helpful in regard to working space -> output space. In particular:
here
here
here and
here

Hope this helps

Cheers

Tim

[Downrigger]

I am happy and confident that the conversion
from working space to output space (whether it be my monitor's space, sRGB for web, or my printer's output colour space) will be accurate and give me the best colour output

Thanks, Tim, for comments and supporting links. The consensus is calming me: work big and then when moving to smaller spaces, trust the software, trust the software, trust....