Panasonic DMC-GX7 - Difficult sunrise image for RawTherapee

I have just tried to process an image of a sunrise from the top of a mountain. I already noticed that similar images are a problem for RawTherapee but this one looks really bad.

Here are two crops of the sun, processed by RawTherapee and by Adobe Camera Raw. I did not make any correction in both the images.

Here is the RawTherapee one:

RT

and here is the Camera Raw one:

ACR

The image becomes even worse if I process it to make the clouds lighter.

Is there a way to make the sun look better with RawTherapee?

If anybody is interested the original raw file is available from here:

www.fsoft.it/temp/P1130719.RW2

I think that it would be nice to be able to make RawTherapee able to handle well such images.

Fulvio Senore

a-P1130719

What you need is an input profile. edit: and for all your photos.
As there is no dcp shipped with RT for this camera, you can:

Using just Defringe in RT:

Edit: as @gaaned92 said using the right DCP profile is best.

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@fsenore
You can get better:
In Exposure module-> check “Highlight reconstruction” and put method: Luminance Recovery.

Greetings.

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Thank you for your help. I did not think about Defringe but it worked very well.
This saved the image: The upper part of the sun is burned and it shows grey after image correction, but it will be easy to clone the grey away.

BTW, do you know where I can find some documentation about this tool? I have read the Rawpedia entry but it does not explain very much.

Thank you, I did not think to try different highlight reconstruction algorithms. CIELAB blending worked best for this image.

Thank you for your help. May I ask you how you created the sun image in your post? It looks very good.

About input profiles I have built one photographing a colorchecker passport and using the included X-Rite software. Using it made only a minimal change to the look of the image, so I was believing that RawTherapee included a profile for the GX7.
In Camera Raw using my profile made the image look much better, instead.

Anyway, selecting the profile did not change the sun appearance. Do you think that it ought to? I was believing that input profiles are about the general color response of the image.

If RawTherapee does not contain a GX7 profile I can shoot and submit the requested images, even if finding a tungsten lamp will not be a simple task. Again, using the profile created by the X-Rite software did not make a significant difference.

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If you use Luminance recovery, you will get a white, burned region.
It can be used here as the overexposed region(sun) is very small in the photo.
The result is very different from CR1 result and quasi identical RT result using an appropriate input profile.
I would not advise to use luminance recovery on photos where the overexposed region is larger (and I don’t like it).

edit:

the list of profiles shipped is located in <RTinstalldir>/dcpprofiles.
@Morgan_Hardwood is the specialist here. As he is picky on the quality of images and use of tungsten lamp, he can help you to take the photos. With the photos he generates the DCP with Dcamprof I think. See for instance Adding Support for New Raw Formats : RICOH GR III

Procedure used:

  • first as No GX7 profile is shipped with RT, I extracted from Adobe DNG converter Panasonic DMC-GX7 Adobe Standard.dcp, and put it in some directory.

  • after opening your photo, I go to color/color management I check custom and I select the file in the directory. check only base table and look table.

  • then as the sun is overexposed, in exposure tab check highlight reconstruction/color propagation. You can use highlight compression to get back the overexposed pixels (in the top of sun).

  • auto matched tone curve doesn’t hurt.

P1130719-2.jpg.out.pp3 (12.2 KB)

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Again, thank you very much for your help. I used the Adobe profile for the GX7 and the result is very good: adding some defringe gave me an almost perfect result.

I didn’t think that an input profile could solve such problems, since the ones I created with the x-rite software did not help. On the other hand the Adobe profile is so much larger than mine that it can contain tons of information for the raw converter…

@fsenore you can help not only yourself but also others by sending me daylight + StdA shots of the target, as described in the RawPedia link you received above.

I have uploaded the requested images for the profile creation. Sorry for the delay but finding an incandescent bulb was not easy.
As requested I opened a Github issue.

Thank you.

Fulvio Senore

Panasonic DMC-GX7 dual-illuminant DCP created and added, will be part of RawTherapee 5.8, or get it now from:
https://github.com/Beep6581/RawTherapee/blob/dev/rtdata/dcpprofiles/Panasonic%20DMC-GX7.dcp

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