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Gray pixels appear cyan on screen, primarily in midtone areas.


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I am trying out Affinity Photo, and a lot of my photographic work is in black and white. Oddly, in Affinity, darker midtone areas have a cyan cast to them on screen. Using the color picker, I can confirm that Affinity believes that the pixels are gray, and when I save the image and open it in another program, the pixels appear gray there. This is frustrating because it makes me not trust the appearance of images in Affinity Photo.

To further debug, I zoomed in very close and took a screenshot and opened that screenshot in Photoshop. Photoshop's color picker confirms that the pixels are somewhere in the cyan range, definitely not the gray that they are saved as.

Since the underlying image is correct, this is some kind of display bug. I have tried changing the RGB color profile in preferences, but that seems to have no effect at all. I normally use ProPhoto RGB, which is the same profile I use in Lightroom and Photoshop where (obviously) this glitch does not occur.

Here is the image zoomed in somewhat in Affiniti, where you can see that the color picker registers a gray tone:

affiniti-original.thumb.png.a8ebdc74db8920e0a367f5e07c94957c.png

And here is a screenshot of a much closer zoom opened in Photoshop demonstrating that there is a cyan cast:

affiniti-zoom-in.thumb.png.c94fe1ff447a37bcf105760848f740aa.png

If there are some additional debugging steps I can perform, or other information I can gather let me know.

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Welcome to the Serif Affinity forums, Aaron.

That sounds like it could be an issue with your Windows Color Management settings, specifically with the color profile assigned to your monitor.

Here are a couple of links that may help:

https://affinityspotlight.com/article/display-colour-management-in-the-affinity-apps/

https://forum.affinity.serif.com/index.php?/topic/99523-faq-the-apps-canvas-is-not-white-whats-happening/&tab=comments#comment-532512

 

-- Walt
Designer, Photo, and Publisher V1 and V2 at latest retail and beta releases
PC:
    Desktop:  Windows 11 Pro, version 23H2, 64GB memory, AMD Ryzen 9 5900 12-Core @ 3.00 GHz, NVIDIA GeForce RTX 3090 

    Laptop:  Windows 11 Pro, version 23H2, 32GB memory, Intel Core i7-10750H @ 2.60GHz, Intel UHD Graphics Comet Lake GT2 and NVIDIA GeForce RTX 3070 Laptop GPU.
iPad:  iPad Pro M1, 12.9": iPadOS 17.4.1, Apple Pencil 2, Magic Keyboard 
Mac:  2023 M2 MacBook Air 15", 16GB memory, macOS Sonoma 14.4.1

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Thanks for the reply, Walt.

I'm skeptical of your suggested approach because a screenshot should not contain colors managed by the output profile of a monitor; if I take a screenshot with a wildly crazy monitor profile and send it to you, it should not appear wildly crazy on your monitor (although that's an experiment we could carry out).

All of that said, I do have a custom color profile applied in Windows, which I generated with my Spyder colorimeter, and which I have used in Lightroom and Photoshop for ages. I'm definitely aware of the ins and outs of color management and have faced no small amount of frustration with how Windows handles it, but my setup is solid and works everywhere else.

I think this is a legitimate Affinity Photo bug.

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16 minutes ago, aaronbieber said:

All of that said, I do have a custom color profile applied in Windows, which I generated with my Spyder colorimeter, and which I have used in Lightroom and Photoshop for ages. I'm definitely aware of the ins and outs of color management and have faced no small amount of frustration with how Windows handles it, but my setup is solid and works everywhere else.

Affinity manages color differently from most other applications, and problems in the monitor color profile will show up in Affinity when they don't show up in other applications. I think the Spotlight article addresses that. In particular, yes, Affinity uses the monitor's profile in generating the display that you see, and thus I believe it will affect screenshots that you take.

The simplest way to check might be to set your monitor to sRGB and see if the problem in Affinity goes away. That will confirm whether it is related to the monitor color profile.

I'm not saying that there isn't some Affinity problem, but your report is similar (not identical, though) to other reports that have been solved by the links I provided.

-- Walt
Designer, Photo, and Publisher V1 and V2 at latest retail and beta releases
PC:
    Desktop:  Windows 11 Pro, version 23H2, 64GB memory, AMD Ryzen 9 5900 12-Core @ 3.00 GHz, NVIDIA GeForce RTX 3090 

    Laptop:  Windows 11 Pro, version 23H2, 32GB memory, Intel Core i7-10750H @ 2.60GHz, Intel UHD Graphics Comet Lake GT2 and NVIDIA GeForce RTX 3070 Laptop GPU.
iPad:  iPad Pro M1, 12.9": iPadOS 17.4.1, Apple Pencil 2, Magic Keyboard 
Mac:  2023 M2 MacBook Air 15", 16GB memory, macOS Sonoma 14.4.1

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I see, that's interesting, thanks for the additional information.

I switched my display back to the basic sRGB profile and I can definitely still see a noticeable cyan cast in these areas in Affinity and not in Photoshop.

Apart from my strong belief that this is a fairly significant color display bug, I think Serif needs to get their eyes on this because I have followed all of the instructions in the article you linked; I have a custom profile generated by a mainstream colorimeter company and it is applied in Windows at the system and user levels. If anything, the concept that Affinity "manages color differently from most other applications" is the problem: Lightroom and Photoshop do not exhibit this behavior. Photoshop remains, for better or worse, the gold standard for this stuff.

I hate to keep comparing to Photoshop, but that's the software I'm trying to replace, and as it stands, I can't do it, I just can't trust what my eyes are seeing in Affinity Photo.

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Thanks for trying it, Aaron.

Someone from Serif will be around to ask more questions sometime. It's after office hours there now, and I'm never sure what kind of staffing they have after hours and over the weekend. It's usually pretty good, but some kinds of problems may be handled by certain staff members, and they prioritize the handling of bug reports based on order of creation, so sometimes it takes a few days for a response depending on what's in the queue and who's available.

-- Walt
Designer, Photo, and Publisher V1 and V2 at latest retail and beta releases
PC:
    Desktop:  Windows 11 Pro, version 23H2, 64GB memory, AMD Ryzen 9 5900 12-Core @ 3.00 GHz, NVIDIA GeForce RTX 3090 

    Laptop:  Windows 11 Pro, version 23H2, 32GB memory, Intel Core i7-10750H @ 2.60GHz, Intel UHD Graphics Comet Lake GT2 and NVIDIA GeForce RTX 3070 Laptop GPU.
iPad:  iPad Pro M1, 12.9": iPadOS 17.4.1, Apple Pencil 2, Magic Keyboard 
Mac:  2023 M2 MacBook Air 15", 16GB memory, macOS Sonoma 14.4.1

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Hi, Gabe.

I am attaching the full version of the file I am looking at, saved as an .afphoto. However, please note that as I described in my original post, there is no sign of this cyan cast in the file itself. Affinity's own color picker sees the off-color pixels as gray, though they appear to me as bluish or greenish.

The above attached screenshot actually captures that precise color, and shows how Photoshop identifies those pixels.

I will be happy to provide more system information, etc., if it will help:

Windows 10 Pro, version 10.0.18362 Build 18362
nVidia GeForce RTX 2060, running the official nVidia driver version 26.21.14.4187
Output to a LG 4K monitor @ 3840x2160, 32-bit color

I am also attaching my custom display profile, which I generated with a Spyder 2 colorimeter.

Affinity-sample-photo.afphoto

LG 4k.icm

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The document looked the same to me when using the standard sRGB profile in Windows.

Can you let me know what the right solution here would be? Based on what Walt said up above, the way to set this up in Affinity may differ from what I am used to, so I'm trying to make sure that I get the most accurate appearance on-screen but also the best possible color depth and accuracy in the file itself.

I did one more experiment, which I think is very interesting. I opened the original 16-bit TIFF in Photoshop, which looks perfect. I choose Edit -> Convert to Profile, and I select ProPhoto RGB and "Perceptual" intent. If I check "Preview," the document takes on a very subtle color cast. This is the same effect, although much less obvious than what I see in Affinity. However, when I click "OK," the color cast disappears and it still looks perfect.

How should I proceed?

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What concerns me is that Lightroom specifically suggests that 16-bit ProPhoto RGB be used to preserve color details:

Lightroom-color-space-tip.png.23d84f89b832ae5da037acc2d689cd0b.png

And Photoshop does a very good job of mapping those non-displayable colors into colors that appear as one would expect (grays look gray, in this case).

To map non-displayable colors for a particular monitor space into that space simply so that things look accurate, rather than maintaining those color values for future edits seems like a destructive way to do this, and that worries me if Affinity is going to overtake Photoshop for professional use.

On the other hand, failing to map them perceptually leaves people like me wondering how much of what I'm seeing is "true." I completely understand that color science is a deep and challenging field, but I think this is a hurdle that Affinity will have to get over if it is to compete.

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  • Staff

You're not converting the file in file in Affinity, but you do in Photoshop, so that's probably where the difference is coming from. 

If you open the same TIFF with the embedded ProPhoto ICC in any app that reads the ICC profile, you will see the same result (a cyan cast). It's not a bug or an issue, but just a consequence of having using a profile that your monitor cannot fully display the document profile. 

As a test, open the attached file in both Photoshop and Photo. You will notice the same cyan/blue cast. 

On 1/21/2020 at 1:44 PM, aaronbieber said:

What concerns me is that Lightroom specifically suggests that 16-bit ProPhoto RGB be used to preserve color details:

That's just a standard message. Lightroom does not know what you're going to do with the image. There is no reason in your case to work in ProPhoto RGB for a grayscale image. Export as 16bit Grayscale and you will have a grayscale image. Why do you use ProPhoto in the first place? Your monitor profile does not come even close to the whole ProPhoto RGB spectrum, so there is no advantage in using it. I suggest you stick with sRGB unless you require ProPhoto for a specific workflow. 

image.png

The big spectrum is ProPhoto, next one down is your 4K profiled monitor, and the smallest one is sRGB. 

Affinity-sample-photo.tiff

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Thanks for that reply, Gabe! I now understand a lot more about how to think about color profiles and color management thanks to your detailed and practical responses here.

Since my images usually end up either on the web or in print, and both of those scenarios are essentially standardized on sRGB, the only "concern" that I have is that manipulating an image with more color data should lead to (at least in my naive understanding) less artifacts, like banding, or similar. For grayscale images it certainly doesn't matter either way.

Simply using the grayscale image as a test because the cast is easier to see, exporting with Adobe RGB (1998) seems to completely solve the problem, so I'll be more mindful of which color space I use when I export from Lightroom in the future.

Again, thanks so much for your patience and detailed replies here!

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  • Staff

Your screen cannot fully display AdobeRGB, so you will probably not be seeing any difference.

image.png

A colour profile does not help to eliminate banding, but a greater bit depth. For web, you should be using sRGB as nothing ever gets colour managed and it's treated as-is, so things will look different if you're using AdobeRGB.

 

Take this for example. This is an sRGB photo.

PDI_Target_sRGB.jpg

And this is the exact same but with a WhackedRGB profile (red is swapped with green, green swapped with blue, blue swapped with red)

PDI_Target_WhackedRGB.jpg

Because this is not colour managed, it looks completely wrong. If in doubt, load this image tagged with Whacked RGB where you want to upload your image. If it shows purple, you know they don't colour manage, and your AdobeRGB will look different :)

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