Beyond frustrated with colour print settings. Would SO appreciate advice. Thanks!

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Originally Posted by Colin Southern

Hi Tim,

No. No conversion necessary; the software will adjust the data correctly when the correct printer profile is selected as part of the printing process (ie one doesn't go Edit -> Convert to profile when doing one's own printing).

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Sorry if you may have misunderstood this step, Myra. Colin is certainly correct: you don't go 'Edit -> Convert to (printer) profile' at any stage. I didn't intend to give you that impression.

If you were printing for yourself, you would "let Photoshop manage colours" - or "apply a printer profile" (depending on what software you were using) as the last step before printing. That is the step in which you ask the software convert your image data to the profile expected by your printer.

In the same way, if you're using an external print lab, it's at this very last step, (after you've made any/all image adjustments in ProPhoto), as part of exporting/saving your file to send to the print lab, that you would convert the image data to sRGB. Indeed this option is usually part of the SAVE (or EXPORT) dialog in most software.

Tim

PS There's been so much rain here in our part of the world today, I fear we'll float to Canada shortly!

Even though my colours are better, I'm still not seeing in the prints what I'm seeing on my old monitor. The yellows and magentas do not seem as apparent. I'm just going to sit down, photograph the same thing about 6 times and then try all the possible combinations.

I did miss that bit and thought I had to have everything, including the ICC conversion when Saving As set to ProPhoto. Sometimes this feels like trying to learn another language from a textbook without being able to hear the correct pronounciation of the words:)

You'd have a long sail ahead of you, Tim!

EDITED: I had written I like the idea of using ProPhoto and converting at the last moment. Then I read Colin's reply in Bobo's thread that stated editing in ProPhoto is not a good thing. Scratch that experiment off the list!

OK, let's see if I've understood what's normal procedure:

1 - device profiles(a) are exactly that: device profiles and should stay with the device => never convert an image to a device profile
(they will be applied by the device when needed, cf. screen calibration profile)

2 - if you send your images to be printed somewhere else, as a final step make sure they are converted to sRGB colour space

3 - editing can be done in any colour space, as long as you stay aware of the pitfalls (out-of-gamut colours) and know how to avoid them

(a) a device profile is any profile you (could) create by measuring the difference between what your image should show
and what it actually shows, and specific for that device (in printing, the device is the printer+ink+paper!)

That said, the advantages of working in any space other than sRGB if you only work for screen or prints to be done by someone
else aren't clear to me.

Remco

Hi Remco

Looking at your points:

1 Almost exactly right.
Except if you're printing for your self using Photoshop, or Lightroom or Aperture or whatever, you'd want to control the conversion to the printer profile (a device profile, as you say) in the application. It isn't done automatically. (Even though the dialog in Photoshop says, weirdly, "Let Photoshop Manage colors" what it means is, you have to make the choice of profile)

2 Always convert to sRGB before sending an image to a lab.
Yes, if you are not sure they know what they're doing. As Colin pointed out earlier, there's no reason why the software at labs couldn't be built to read the colour profile attached to an image and correctly interpret the data. But they don't.

3 Yes


The main advantages of working in a bigger space than sRGB are twofold:
First: Any DSLR in the world captures more colours than are in sRGB (or Adobe RGB for that matter) The general rule is don't throw those colours away unnecessarily. There are many monitors on the market with gamuts wider than sRGB and the number of these is growing and prices are coming down. Most Quality inkjet printers show lots of colours that are outside of sRGB.
As these technologies continue to improve, more highly saturated colours in your images will be able to be reproduced accurately.

Second: (this is more subtle) Changes that you may make to your image in processing, shift tone and colour values along a gradient. The wider the working colour space is, the smoother those changes may be. Steepening the gradient, and especially confining to a small space like sRGB, risks introducing artifacts like posterisation into areas of subtle tonal gradation in your photograph.
This is why modern photographic applications like Lightroom and Aperture don't give you any opportunity to choose a tiny color space like sRGB as its working/editing space. Lightroom uses a variant of ProPhotoRGB by default.

The short answer is, when you need to have your final image in sRGB (for display on the lowest common denominator monitor, to send to the web, or to send to a 'normal' lab) control that conversion yourself, at the last possible minute.

Cheers

Tim

Hi Tim,

Quote:

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Originally Posted by Macmahon

The main advantages of working in a bigger space than sRGB are twofold:
First: Any DSLR in the world captures more colours than are in sRGB (or Adobe RGB for that matter) The general rule is don't throw those colours away unnecessarily. There are many monitors on the market with gamuts wider than sRGB and the number of these is growing and prices are coming down. Most Quality inkjet printers show lots of colours that are outside of sRGB.
As these technologies continue to improve, more highly saturated colours in your images will be able to be reproduced accurately.

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Yes, it is a general rule -- and in theory it makes sense, but I don't think that many folks have a good feel for this in practice. If you mixed 50 sRGB prints where any out of gamut colours had been properly handled by an appropriate rendering intent in with 50 Adobe RGB Prints with the slightly wider gamut and asked folks to sort them into their respective piles, the results would be a lottery. In reality, the differences are very VERY subtle. Most folks just can't see the differences.

Quote:

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Second: (this is more subtle) Changes that you may make to your image in processing, shift tone and colour values along a gradient. The wider the working colour space is, the smoother those changes may be. Steepening the gradient, and especially confining to an 8-bit colour space like sRGB, risks introducing artifacts like posterisation into areas of subtle tonal gradation in your photograph.

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Um, no and no. The bigger the space the greater the greater the variance in colour (for a smaller gamut) a minimum increment must represent. I think you may be confusing colourspace sizes with 8 -v- 16 bit processing. Think of a staircase that has 100 steps and is 100 feet high (Prophoto); if you need to get to somewhere that's 100 feet high then that's the right staircase for the job, but the difference between levels (ie each step) is going to be one foot. If you only need to go up 10 feet - and you have a staircase that's 100 feet tall, then each step is going to represent 10% of the journey. Instead - if you use a smaller staircase that still has 100 steps - but is only 10 feet high - then each step is only 1%. Also, sRGB can be 8 or 16 bit ... it's only formats like JPEG that are 8 bit only (although an 8 bit jpeg can still be in sRGB, Adobe RGB, or even ProPhoto).

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This is why modern photographic applications like Lightroom and Aperture don't give you any opportunity to choose a tiny color space like sRGB as its working/editing space. Lightroom uses a variant of ProPhotoRGB by default.

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Um, no -- I think you'll find that the reason is that they want to ensure that no colours are clipped (many photographers get a bit "upset" at the thought of that). But it's not really an issue in LR as I understand that they'll get converted to sRGB by default.

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Originally Posted by Colin Southern

Hi Tim,

Um, no and no. The bigger the space the greater the greater the variance in colour (for a smaller gamut) a minimum increment must represent. I think you may be confusing colourspace sizes with 8 -v- 16 bit processing. Think of a staircase that has 100 steps and is 100 feet high (Prophoto); if you need to get to somewhere that's 100 feet high then that's the right staircase for the job, but the difference between levels (ie each step) is going to be one foot. If you only need to go up 10 feet - and you have a staircase that's 100 feet tall, then each step is going to represent 10% of the journey. Instead - if you use a smaller staircase that still has 100 steps - but is only 10 feet high - then each step is only 1%. Also, sRGB can be 8 or 16 bit ... it's only formats like JPEG that are 8 bit only (although an 8 bit jpeg can still be in sRGB, Adobe RGB, or even ProPhoto).

Um, no -- I think you'll find that the reason is that they want to ensure that no colours are clipped (many photographers get a bit "upset" at the thought of that). But it's not really an issue in LR as I understand that they'll get converted to sRGB by default.

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Colin
You're right to draw attention to the particular difficulties with an 8 bit encoded data file. Undertake adjustments on a JPEG with much care! I didn't want to get too technical, but the staircase argument doesn't account for gamma. The colour distribution is not linear.

Lightroom never, at any part of its workflow, converts anything to sRGB by default. Nothing is done inside Lightroom in sRGB at all. Lightroom converts all imported images to ProPhoto and in its editing workspace uses a shallow gamma version of ProPhoto for the reasons I described. Unlike in Photoshop, the user has no control over this default at all.

You can deliberately use Lightroom's export routine to convert to sRGB when exporting a copy of an image for one of the purposes discussed above. The original image data, ProPhoto encoded, in LR's catalog, is not affected by that.

As well as importing RAW files you can also choose to import into Lightroom a TIFF or JPEG image whose colour range had been previously limited to sRGB. Lightroom immediately converts such an image to ProPhoto for editing, even though the prior conversion to sRGB 'clipped' the range of colours the camera may have recorded. This is a very sub-optimal thing to do, of course. From time to time it's necessary when someone brings along an sRGB encoded JPEG for printing. My heart sinks. But we do our best. :)

Cheers

Tim

Hi Tim,

Quote:

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Originally Posted by Macmahon

Colin
You're right to draw attention to the particular difficulties with an 8 bit encoded data file. Undertake adjustments on a JPEG with much care!

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Yup - but - that's not why I mention it. I'm just trying to draw attention to the fact that sRGB isn't 8 Bit as you mentioned; it's a colour space, and as such, can be any bit depth. It's when you start working in 8 bit that you can have issues with graduations; it's a bit depth issue, not a colour space issue.

Quote:

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I didn't want to get too technical, but the staircase argument doesn't account for gamma. The colour distribution is not linear.

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It doesn't need to - my point is that the bigger the colour space - the greater (not less) the chances of issues with smooth graduations. Thus the "advantage" you mentioned for Prophoto is actually the exact opposite - it's a disadvantage.

Quote:

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Lightroom never, at any part of its workflow, converts anything to sRGB by default. Nothing is done inside Lightroom in sRGB at all. Lightroom converts all imported images to ProPhoto and in its editing workspace uses a shallow gamma version of ProPhoto for the reasons I described. Unlike in Photoshop, the user has no control over this default at all.

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I'm talking about when files are exported - not how they're handled internally.

Quote:

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Originally Posted by Maritimer1

Even though my colours are better, I'm still not seeing in the prints what I'm seeing on my old monitor. The yellows and magentas do not seem as apparent. I'm just going to sit down, photograph the same thing about 6 times and then try all the possible combinations.

I did miss that bit and thought I had to have everything, including the ICC conversion when Saving As set to ProPhoto. Sometimes this feels like trying to learn another language from a textbook without being able to hear the correct pronounciation of the words:)

You'd have a long sail ahead of you, Tim!

EDITED: I had written I like the idea of using ProPhoto and converting at the last moment. Then I read Colin's reply in Bobo's thread that stated editing in ProPhoto is not a good thing. Scratch that experiment off the list!

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Hi Myra

Did you ever get to the bottom of the sRGB ProPhotRGB wrangle? Are you happy with your screen print match?
Here is another good discussion of this issue. http://photo.net/digital-darkroom-forum/00ZA7Q?start=0

Cheers

Tim

Hi Tim,

Yes, I have to put everything in the sRGB settings and make sure the image is only 8 bit when I send it to the printer. Kind of seems a waste, but that's what has worked. Thanks for the link to the other discussion.

Myra