color mismatch when using HDR


#1

I have found that when using the HDR function in RT 5.4 the saved image does not match the color and contrast of the preview (see fig_1). When using other functions the matching between the preview and the saved image is good (see fig_2). Do I miss someting or is it a bug?


(Mica) #2

What color profile so you have assigned for your output image?


#3

The color profile for output is RT_sRGB. I have also tried other profiles for output, but it does not solve the problem.


(Ingo Weyrich) #4

grafik


#5

That’s really a shame. This tool works very well, but I need to control the effect by watching at the entire picture. Is there any trick to overcome this limitation?


(Ingo Weyrich) #6

Can you provide a file and your pp3 to reproduce the issue?


(Alberto) #7

what @heckflosse wrote is definitely true, but the difference here seems quite big. can you share a raw and pp3? also, are you using colour management consistently across your apps?


#8

Here is the raw file. The only applications used are RT 5.4 and Windows Picture Viewer to show the jpeg images; anyway, the same difference also appears in the thumbnails of the RT Navigator.

IMG_0564.CR2 (22.1 MB)


#9

Here is the Fig_1 pp3…

IMG_0564_1.jpg.out.pp3 (11.2 KB)


#10

…and here is the Fig_2 pp3.IMG_0564_2.jpg.out.pp3 (11.2 KB)


(Alberto) #11

Hi,
thanks for the files. I think you might want to check your colour management settings. Here is what I get:


There might be some differences, but (if any) they are way smaller than what you showed above…


#12

Hi,
thank you very much for your suggestion. I have now changed the monitor profile and it works much better. I have choosen a profile with the name of the device (ASUS_X540SAA_8086_AE0D15CA). However, since I calibrated the monitor using the Intel Graphic Control Panel, maybe there is another custom profile saved somwhere after this calibration?


(Alberto) #13

Hi,

maybe you know this already, but just in case: calibration and profiling are two different things. (see e.g. https://ninedegreesbelow.com/photography/monitor-profile-calibrate-confuse.html).
For profiling, you need a device (colorimeter or spectrometer). Anyway, the important thing for this thread (note, having a properly profiled screen is important, but that’s not the point here…) is to have consistent colour management settings across different applications. Otherwise, your pictures are going to look different depending on the viewer you use, which will quickly drive you crazy :wink:


#14

Hi Alberto,
thank you for the information and the link. I now undestand that monitor calibration does not matter for the present topic and the relevant point is that all applications should use the same color profile to show the same image with same appearance.
I have tryed to set different color profiles in the windows color menager, but none seems to affect the appearance of the image shown by Windows Picture Viewer. Thus I guess that this software is using the sRGB profile. So I set the output and the monitor profiles of RT to sRGB. Now, when the zoom is greater than 50%, the preview in RT looks substantially similar to the image shown in Windows Picture Viewer, but when zooming out the look is different. However, your result, Alberto, was quite good at 17%; maybe you have a different machine? For shure you have a larger monitor resolution (yours 1920x1080 vs mine 1360x768); could this indirectly change the behavior of RT, because it works on the picture currently shown on the monitor?


(Alberto) #15

yes, that’s definitely a factor. as @heckflosse wrote, only the 1:1 view ensures that the preview is fully accurate. with smaller sizes, you might get a preview that is slightly off. we had to make some compromises between accuracy and speed, and we optimized the trade-off for screens that are at least “full hd”. that said, I sometimes use my old laptop for editing, which has a lower res screen, and although I see some differences there, they are usually minor…


#16

OK, it’s clear. Thank you very much for you help.


(Morgan Hardwood) #17

I wanted to confirm that the preview is very close to the saved image when zoomed-to-fit. If you see significant differences, look for their cause in other tools and in color (mis-)management.


#18

I can’t find where the color management is wrong. I have checked: 1) windows color management/device; 2) windows color management/advanced; 3) RT output profile; 4) RT preview profile. Do I miss anything?


(Alberto) #19

I might be wrong, but I think the windows default viewer is not colour managed. to confirm, can you try using another viewer?


#20

I have tried using RT to view the jpg file and it differs from the raw preview. In the picture below: on the left the raw file, on center the jpg file in RT, on right the jpg file in Windows Viewer.
To consolidate my understanding: a non-colour-managed software shouldn’t use a sRGB profile?