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Wetpixel Live: Color Spaces for Underwater Image-Makers

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Many image-makers find that the colors in their images are not faithfully reproduced when they share images online or in print. @Alex_Mustard and @adamhanlon discuss the cause of this and go on to talk about how selecting the correct color space for a given purpose when exporting files can help ensure that our work is faithfully represented when it is displayed.
 

 

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Posted (edited)

This is a very interesting video adressing the notorious problem of color accuracy between different devices. My personal experience is in line with the video that the transition from display on a monitor (even when a high quality one) and printing is the most problematic.

When using LR and/or PS (or similar software), I wonder why it is it not possible to export a photo in the CMYK color space to send to a printing service and get the same colors in a (calibrated) print as one can see on a (calibrated) monitor in sRGB or aRGB. Is it just because the software engineers did not yet identify this very important problem (and instead create endless amounts of filters and other gimmicks), or is there an intrinsic, technical, problem that makes an export in CYMK impossible?

Wolfgang

Edited by Architeuthis

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1 hour ago, Architeuthis said:

This is a very interesting video adressing the notorious problem of color accuracy between different devices. My personal experience is in line with the video that the transition from display on a monitor (even when a high quality one) and printing is the most problematic.

When using LR and/or PS (or similar software), I wonder why it is it not possible to export a photo in the CMYK color space to send to a printing service and get the same colors in a (calibrated) print as one can see on a (calibrated) monitor in sRGB or aRGB. Is it just because the software engineers did not yet identify this very important problem (and instead create endless amounts of filters and other gimmicks), or is there an intrinsic, technical, problem that makes an export in CYMK impossible?

Wolfgang

When you are talking about a printing service - producing a print of one of your images, this is different to printing in a book or magazine.  Books and magazines print CMYK images with a fairly standardised set of CMYK inks.  Printing a photo to hang on your wall is a an RGB process for most types of printers - designed to print RGB images and with modern inkejets you can print the entire Adobe RGB gamut and sometimes more..

Matching print to monitor is problematic - the monitor is backlit and capable of quite a bigger range of brightness than a print viewed in reflected light.  It is indeed possible to do quite good matching from print to screen, by soft proofing.  You need:

  • A calibrated monitor, set at the right brightness (~100-120 cd/m2)
  • An ICC colour profile for the printer/paper combination you are printing on.
  • All the settings in the printer driver you used to print the target if you are printing yourself
  • An application such as photoshop that allows you to soft proof the image

The colour profile is downloadable from good quality labs or if you have your own quality inkjet printer you can print a calibration target on your chosen paper and have the target scanned an ICC profile produced.

In Photoshop you go to View +> Proof setup  => custom  and select the chosen printer profile and the rendering intent.  Click OK and it will simulate your image.  Crtl Y clicks back and forth between normal view and soft proof view.  Sometimes the changes are subtle sometimes not depending on the capability of the printer.

Some articles that are useful:

https://imagescience.com.au/knowledge/why-your-prints-are-too-dark

https://imagescience.com.au/knowledge/guide-to-managing-colour-space-in-print-files

https://imagescience.com.au/knowledge/using-icc-output-profiles

 

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3 hours ago, adamhanlon said:

Many image-makers find that the colors in their images are not faithfully reproduced when they share images online or in print. @Alex_Mustard and @adamhanlon discuss the cause of this and go on to talk about how selecting the correct color space for a given purpose when exporting files can help ensure that our work is faithfully represented when it is displayed.
 

 

Hi Adam and Alex,

you mention that sometimes posting images on social media results in problems, one of the issues is that Facebook strips the EXIF data and colour profile from your image when it uploads and they may compress it some which can results in subtle changes.  If you converted the image to sRGB in most cases this should not be a problem as browsers generally assume an image is sRGB in the absence of any other information.  Many browsers these days but not all will read and honour a image tagged with a colour space - where you run into trouble is when a non s-RGB image is loaded into a non-colour managed browser and it displays it assuming the image is sRGB -that is where the image will look really bad. 

The other point is that of calibration.  The combined system of computer/monitor/image processing software/colour profiles assumes that the monitor will display a colour a certain way.  This seems to be less of a problem than it used to be as LED illuminated monitors are much more stable and higher end monitors are much closer to calibrated out of the box, but cheaper monitors can often have significant colour shifts.  If you have a calibrated monitor you have a much better chance of having the image display the same or as close to the same as is possible given hardware differences on some one else's device. Ideally everything would be calibrated - but that is not going happen of course.  But at least if you are running a calibrated system you can be more confident of contest judges, printing services and other people with calibrated systems etc. seeing the same image you prepared on your system.

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On 6/6/2021 at 2:04 PM, ChrisRoss said:

Hi Adam and Alex,

you mention that sometimes posting images on social media results in problems, one of the issues is that Facebook strips the EXIF data and colour profile from your image when it uploads and they may compress it some which can results in subtle changes.  If you converted the image to sRGB in most cases this should not be a problem as browsers generally assume an image is sRGB in the absence of any other information.  Many browsers these days but not all will read and honour a image tagged with a colour space - where you run into trouble is when a non s-RGB image is loaded into a non-colour managed browser and it displays it assuming the image is sRGB -that is where the image will look really bad. 

The other point is that of calibration.  The combined system of computer/monitor/image processing software/colour profiles assumes that the monitor will display a colour a certain way.  This seems to be less of a problem than it used to be as LED illuminated monitors are much more stable and higher end monitors are much closer to calibrated out of the box, but cheaper monitors can often have significant colour shifts.  If you have a calibrated monitor you have a much better chance of having the image display the same or as close to the same as is possible given hardware differences on some one else's device. Ideally everything would be calibrated - but that is not going happen of course.  But at least if you are running a calibrated system you can be more confident of contest judges, printing services and other people with calibrated systems etc. seeing the same image you prepared on your system.

I produce sRGB 2048 pixels wide images for facebook and 1080 wide for instagram I also print on sRGB actually and to be frank I never had an issue of loss of quality or color. While in some cases the issue was the brightness when you go and print compared to what you had on the screen

As long as you proof your images in sRGB and use decent equipment I do not see major issues for the average home user that occasionally sells a print (I do and nobody complained ever)

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2 hours ago, Interceptor121 said:

I produce sRGB 2048 pixels wide images for facebook and 1080 wide for instagram I also print on sRGB actually and to be frank I never had an issue of loss of quality or color. While in some cases the issue was the brightness when you go and print compared to what you had on the screen

I am a bit stingier with my pixels, more like 640 to 800 on the long axis. As well images are watermarked. Most folks seem to be using their phones to look at these sites so why bother with more rez, that is what my website is for.

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3 hours ago, Interceptor121 said:

I produce sRGB 2048 pixels wide images for facebook and 1080 wide for instagram I also print on sRGB actually and to be frank I never had an issue of loss of quality or color. While in some cases the issue was the brightness when you go and print compared to what you had on the screen

As long as you proof your images in sRGB and use decent equipment I do not see major issues for the average home user that occasionally sells a print (I do and nobody complained ever)

It really depends on what type of monitor you have - wide gamut monitors will display 100% of Adobe RGB and you can actually see the difference particularly in the blues when you convert to sRGB for the web.  If you have a standard gamut monitor , they usually only display sRGB and you can't tell the difference between the two colour spaces and ignorance is bliss!  :)

If you are having issues with print brightness this is down to setting your monitor at the correct luminosity for printing and to a lesser extent have the right sort of room lighting - in bright room lighting you need to brighten your display a little to compensate for the room lighting.    This also assumes you'll be viewing the print under appropriate luminosity lighting.  When you calibrate your monitor the first step is setting the luminosity.  This can be a problem as some gaming monitors for example are difficult to turn down enough to achieve the recommended luminosity.  If your monitor is too bright you will adjust the image such that it prints too dark.

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It really depends on what type of monitor you have - wide gamut monitors will display 100% of Adobe RGB and you can actually see the difference particularly in the blues when you convert to sRGB for the web.  If you have a standard gamut monitor , they usually only display sRGB and you can't tell the difference between the two colour spaces and ignorance is bliss! 
If you are having issues with print brightness this is down to setting your monitor at the correct luminosity for printing and to a lesser extent have the right sort of room lighting - in bright room lighting you need to brighten your display a little to compensate for the room lighting.    This also assumes you'll be viewing the print under appropriate luminosity lighting.  When you calibrate your monitor the first step is setting the luminosity.  This can be a problem as some gaming monitors for example are difficult to turn down enough to achieve the recommended luminosity.  If your monitor is too bright you will adjust the image such that it prints too dark.

I don’t want to make my monitor look like paper. It is just a matter if understanding how the print will come out
Paper has less DR than the screen so it is normal to have some compression. I had only one or two occasions where the iMage came a tad dark but in general is not an issue


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1 hour ago, Interceptor121 said:


I don’t want to make my monitor look like paper. It is just a matter if understanding how the print will come out
Paper has less DR than the screen so it is normal to have some compression. I had only one or two occasions where the iMage came a tad dark but in general is not an issue


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The idea is not to make your monitor look like paper, it is to set the right maximum luminance to suit your editing environment.  The images will look every bit as vibrant as they do on a monitor that is set too bright, but they are a much better match for printing.  Soft proofing simulates the lower DR of paper but you only turn that on briefly when getting ready to print - it's a very good system and I use it for inkjet printing on my Epson printer it works remarkably well.

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The idea is not to make your monitor look like paper, it is to set the right maximum luminance to suit your editing environment.  The images will look every bit as vibrant as they do on a monitor that is set too bright, but they are a much better match for printing.  Soft proofing simulates the lower DR of paper but you only turn that on briefly when getting ready to print - it's a very good system and I use it for inkjet printing on my Epson printer it works remarkably well.

I use soft proofing of sRGB however if you wanted to be really precise you needed to press simulate paper and ink however that option is usually greyed out unless you load printers profiles
Soft proofing only shows out or in gamut and out or in display gamut for sRGB displayp3 and adobergb however doesn’t really simulate paper unless you tick the option
Consider that the mid point should not really move after proofing but when the paper has less DR than the sRGB space (which mostly it does) it looses on the bright tones. So in effect you should adapt the editing accordingly to consider 6-7 stops.
On images with a lot of DR you should try and do some tone mapping to fit it. You can of course try do reduce your display brightness but this is not very effective
In the majority of cases I have had no issues in some shots with a lot of DR it struggles a bit


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8 hours ago, Interceptor121 said:


I use soft proofing of sRGB however if you wanted to be really precise you needed to press simulate paper and ink however that option is usually greyed out unless you load printers profiles
Soft proofing only shows out or in gamut and out or in display gamut for sRGB displayp3 and adobergb however doesn’t really simulate paper unless you tick the option
Consider that the mid point should not really move after proofing but when the paper has less DR than the sRGB space (which mostly it does) it looses on the bright tones. So in effect you should adapt the editing accordingly to consider 6-7 stops.
On images with a lot of DR you should try and do some tone mapping to fit it. You can of course try do reduce your display brightness but this is not very effective
In the majority of cases I have had no issues in some shots with a lot of DR it struggles a bit


Sent from my iPhone using Tapatalk

I am talking about using paper profiles and I have them loaded for the papers I print with.  When you do that it is surprisingly good at showing what the image will look like and also at printing the image.  Simulate paper white needs to be used with caution - for it to be effective you can't have any white in your field of view and it used not so much to preview as to check whether the print will show shadow/highlight  detail or not.  This link gives a good discussion on their use:  https://imagescience.com.au/knowledge/using-icc-output-profiles

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I am talking about using paper profiles and I have them loaded for the papers I print with.  When you do that it is surprisingly good at showing what the image will look like and also at printing the image.  Simulate paper white needs to be used with caution - for it to be effective you can't have any white in your field of view and it used not so much to preview as to check whether the print will show shadow/highlight  detail or not.  This link gives a good discussion on their use:  https://imagescience.com.au/knowledge/using-icc-output-profiles

I am aware of ICC profiles however in the case I had problems I was printing on cotton canvas through a lab. I very rarely print on paper as now all club competitions are PDI. I don’t think the el cheapo printer A4 I have at home has ICC profiles available but I can check


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Posted (edited)

Nowadays colour printers have accessible colour profiles that can be useful when soft proofing or printing. If your OS is Windows the ICC colour profiles are at this location: C:\WINDOWS\system32\spool\drivers\color and it is easy to select them in ICC aware printing application. For instance, the file names of the ICC colour profiles of my el-cheapo Canon P7200 look like these: CNBBAMB0.ICM; CNBBAMC0.ICM; CNBBADB0.ICM. 

Also, I usually ask the online printing services to have their ICC colour profile for the media I selected to print on and adjust the file accordingly. These additional adjustments never fail to deliver improved results.

 

 

Edited by scuba_d
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On 6/9/2021 at 11:13 AM, scuba_d said:

Nowadays colour printers have accessible colour profiles that can be useful when soft proofing or printing. If your OS is Windows the ICC colour profiles are at this location: C:\WINDOWS\system32\spool\drivers\color and it is easy to select them in ICC aware printing application. For instance, the file names of the ICC colour profiles of my el-cheapo Canon P7200 look like these: CNBBAMB0.ICM; CNBBAMC0.ICM; CNBBADB0.ICM. 

Also, I usually ask the online printing services to have their ICC colour profile for the media I selected to print on and adjust the file accordingly. These additional adjustments never fail to deliver improved results.

 

 

The print lab I use requires sRGB or Adobe and do the optimisation themselves to the printer you can switch it off if you prefer

I don't have  a canon prograf 2000 like they do and neither have the exact drivers but it has been working fine so far

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Posted (edited)

I am not quite sure, but the optimisations the labs do are mostly automatic –pre-sets. I believe you can do much better than that. If you would like to try next time, ask for the ICC colour profile of the Prograf, for the media they are going to print on, and copy/paste it in the location I pointed out earlier. Then open the file you are going to send to the lab in your favourite editing program and soft proof using this particular colour profile. This way you will see exactly how your file will be printed on this particular printer/media and also the colour gamut it has. Adjust the file so it looks pretty when you soft proof. I am sure you will achieve a better outcome, although your colour management needs to be well established, especially your monitor, viewing environment and the colour settings in your editing program.

Edited by scuba_d

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9 hours ago, scuba_d said:

I am not quite sure, but the optimisations the labs do are mostly automatic –pre-sets. I believe you can do much better than that. If you would like to try next time, ask for the ICC colour profile of the Prograf, for the media they are going to print on, and copy/paste it in the location I pointed out earlier. Then open the file you are going to send to the lab in your favourite editing program and soft proof using this particular colour profile. This way you will see exactly how your file will be printed on this particular printer/media and also the colour gamut it has. Adjust the file so it looks pretty when you soft proof. I am sure you will achieve a better outcome, although your colour management needs to be well established, especially your monitor, viewing environment and the colour settings in your editing program.

In particular you need a wide gamut monitor, a standard monitor that only displays sRGB you won't be able to see the additional colours and can only tell they are there but not visible using the gamut warning.

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I am not quite sure, but the optimisations the labs do are mostly automatic –pre-sets. I believe you can do much better than that. If you would like to try next time, ask for the ICC colour profile of the Prograf, for the media they are going to print on, and copy/paste it in the location I pointed out earlier. Then open the file you are going to send to the lab in your favourite editing program and soft proof using this particular colour profile. This way you will see exactly how your file will be printed on this particular printer/media and also the colour gamut it has. Adjust the file so it looks pretty when you soft proof. I am sure you will achieve a better outcome, although your colour management needs to be well established, especially your monitor, viewing environment and the colour settings in your editing program.

The optimisations of the lab I use relate to scaling/sharpening not color


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