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Darkening of the uploaded pics

Posted by Łukasz Kruszewski  
Łukasz Kruszewski April 20, 2017 08:53PM
Hi. I've uploaded a few photos today and I am sure that the "Mindat upload system" makes them darker than they are. I am especially conerned about this one: https://www.mindat.org/photo-816793.html. Is there any bug within?


Luke K.
AM Mizunaka April 20, 2017 09:37PM
Had an issue with this image as well. Darker and off color.

It looks ok when viewing in Chrome. Problem appears when viewing the image in Firefox.
Martin Rich April 21, 2017 12:34AM
Not long ago, there was a discussion on mindat about this. If I remember correct it has to do with the adjustment of the camera or photo editing software. If the adjustment is set on AdobeRGB instead of sRGB this could be cause a colour shift.
Keith Compton April 21, 2017 12:38AM
Hi Lukasz

I have noticed a few very dark ones uploaded in the last few days - So dark I would not have approved them in the first place.
I use Windows, Chrome and Firefox as an alternate.

I cannot say that I have noticed Mindat making them darker. I think I would have to upload a photo personally to check this. I'll try on the when I am planning to take some photos.


Uwe Kolitsch April 21, 2017 08:16AM
816793: can you post the original photo also in this thread, just to see if it appears brighter then?
Łukasz Kruszewski April 21, 2017 11:16PM
Uh, uh, which one was it.... (-; Maybe this one:

sorry - will try to convert to JPG and upload it later.

I am sure the pics I have are way more bright that here on Mindat (or, rather/maybe, the Chrome/Firefox etc.?); I am uploading them also to Facebook, and they are OK.

P.S.: same problem today.
Ralph Bottrill April 24, 2017 02:55AM
Some of my photos have come up a bit darker than set in the past, though my adjustments are usually pretty basic: cropping, brightness and contrast, never noticed an Adobe option.
Ronald J. Pellar April 26, 2017 08:26PM
Don't worry about the AdobeRGB or sRGB options. Both Windows and Apple have color management built in and will properly convert between color spaces. When the image is converted to a particular format, e.g., JPEG, the format usually has a predefined color space that the color management software will convert to. I have always used JPEG to upload and have never noticed this problem. It seems to be a recent problem that has popped up during the recent bug fixes that Jolyon is working on. I suspect that when he is done these problems will go away.
Łukasz Kruszewski May 02, 2017 05:47PM
Just tried with Mozilla Firefox - same story. Mindat is doing sth wrong with pictures while uploading. Please fix it.
Jolyon & Katya Ralph May 02, 2017 07:03PM
Left is the mindat photo page, right is your original image as viewed in the browser.

Jolyon & Katya Ralph May 02, 2017 07:06PM
The problem appears to be your image has been uploaded without an embedded color profile, so the system assumes it is sRGB. If you have been editing your files in AdobeRGB, ProPhoto or any other different profile then your image WILL look darker when viewed in a browser that has to guess what your image profile should be.

Make sure that you are including the embedded profile and mindat should handle it fine.

Łukasz Kruszewski May 02, 2017 08:52PM
Jolyon, agreed, but I am uploading pics to Mindat for some years and I didn't have this problem before. Also, I've compared today pics with the ones opened in my computers' Windows Photo Viewer, and there is a large difference...


Łukasz Kruszewski May 02, 2017 10:24PM
Btw, the pics I do are not edited in any of such programmes like Adobe P. They are exactly the same as they were before the problem started appearing. So I assume sth must have changed rather here on Mindat.
Jolyon & Katya Ralph May 03, 2017 07:36AM
Well, as I showed, the original photo + the photo page appear identical to me, so I am really not sure what we are doing wrong!
Łukasz Kruszewski May 03, 2017 05:12PM
This is really strange... My comparison shows a large reduction of brightness when compared between Mindat-uploaded and Windows-opened file(s)...
Jolyon & Katya Ralph May 03, 2017 06:25PM
Open your image in Chrome and see what it looks like
Ronald J. Pellar May 03, 2017 07:05PM
Uploading photos in JPEG do not present any problems that I can see. The JPEG format has a predefined color space and needs no embeddec profile. You might try converting one of your photos to JPEG and uploading to see if you still have the problem.
Jolyon & Katya Ralph May 03, 2017 07:20PM
Ok, that's interesting but not what we see in practice.

Here I have taken the same image and saved it twice, both times without any embedded profile.

FIrstly, this is the image when the working colour space in Photoshop is sRGB.

Now, exactly the same image, except in Photoshop I have converted the image to the AdobeRGB profile, and again saved it with no embedded profile

So, as you can see, it DOES make a difference what color space you're working in if you save JPEG files without an embedded proifile.
open | download - profileAdobe.jpg (353.7 KB)
Łukasz Kruszewski May 03, 2017 11:04PM
These pics look almost exactly the same to me...
Ronald J. Pellar May 04, 2017 07:16PM

The sRGB color space has a smaller gamut than AdobeRGB and converting sRGB to AdobeRGB should have NO effect whatsoever. (This is why I recommend that the DSLR space within the camera should be AdobeRGB) When converted to JPEG, the color space is also converted to YCrCb color space which is an old TV transmission color space and has a gamut similar to sRGB but is a smaller gamut than AdobeRGB. There should be no change in image appearance in the test you conducted and I do not see any difference on my monitor.

I suspect the lightness/darkness problem may be related to gamma. The sRGB and YCrCb color space are for a gamma of 2.2. Some older Mac displays used a gamma of 1.8. The color values adjusted for a gamma 1.8 display will look darker when viewed on a gamma 2.2 display. This was a major problem for the early projection displays used with a Mac, but it is my understanding that the newer Macs have changed their gamma to 2.2 and should no longer have this problem.

Edited 1 time(s). Last edit at 05/04/2017 07:20PM by Ronald J. Pellar.
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