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Bug #11857

Darktable applying some lense deformation by default

Added by Rafael Linux User almost 2 years ago. Updated almost 2 years ago.

Status:
Closed: invalid
Priority:
Low
Assignee:
-
Category:
General
Target version:
Start date:
12/15/2017
Due date:
% Done:

0%

Estimated time:
Affected Version:
2.2.5
System:
openSUSE
bitness:
64-bit
hardware architecture:
amd64/x86

Description

First, I must say this issue is happening with Darktable too with Panasonic GX8 RAW files, but I'm guessing both applications are using some middleware where is located the issue.

I'm using a Panasonic DMC GX8 camera and taking photos in RAW. When I view RAW images (with Gwenview or Digikam) the picture showed if fine, cause their are showing the embedded JPEG. However, if I open to edit the RAW file with Darktable or even Digikam, some lense is applied, distorting the photo (like with a wide angle lense).

I attach an example comparing the exported TIFF (only velvia filter applied on Darktable) and the RAW file. You can notice clearly the effect in upper and lower stairs.

That is happening in all GX8 RAW files. I haven't this issue with my previous Sony A700 with RAW files.

Please, could you give some orientation about how to solve this problem or where is the problem located?

Thank you

darktable distontion on raw GX8 files.jpg (138 KB) darktable distontion on raw GX8 files.jpg Rafael Linux User, 12/15/2017 03:39 AM
darktable - no camera found.png (15.6 KB) darktable - no camera found.png Rafael Linux User, 12/31/2017 06:30 PM

History

#1 Updated by Tobias Ellinghaus almost 2 years ago

  • Status changed from New to Closed: invalid

It is actually the other way round. Your camera seems to apply lens correction to the generated JPEG files. What darktable is showing you is the actual image captured by the sensor without such processing applied. You can however have lens correction in darktable, too, by using the module of the same name in the correction group. As long as you are not touching any controls in it (don't set camera, lens, aperture, focal length, ... manually) you can even store it as a preset that gets auto applied to all your images.

#2 Updated by Roman Lebedev almost 2 years ago

  • Target version set to 2.4.0

#3 Updated by Rafael Linux User almost 2 years ago

Well, it's a fact than the same is happening editing from Digikam these Panasonic RAW files. However, I think the "middleware" that reads the data should apply that lens filter, cause there are no lens correction filters for Darktable (there is no any selectable lenses, but for Sony there was a lot).

Who can make that lense correction? Who are the "middleware" (or decoder, I don't know the real word) developers to ask them for help?

Thank you

#4 Updated by Tobias Ellinghaus almost 2 years ago

For lens correction darktable uses lensfun. See this page for how to create the lens correction profiles and a way to ask for help: http://wilson.bronger.org/lens_calibration_tutorial/

#5 Updated by Rafael Linux User almost 2 years ago

Thank you!! That's what I need to know!

Go on with you AWESOME DARKTABLE!!

#6 Updated by Rafael Linux User almost 2 years ago

Sorry, but after trying to get work my camera/lens asking to exiv2 group and creating ".exiv2" file, I discovered that Darktable is not recognizing that the camera is a GX8. However, exiv2 is showing correctly DMC-GX8, as you can see:

exiv2 -pa _1000731.RW2 | grep -i 'lens\|model\|make'Exif.PanasonicRaw.Make Ascii 10 Panasonic

Exif.PanasonicRaw.Model Ascii 8 DMC-GX8
Exif.Image.Make Ascii 10 Panasonic
Exif.Image.Model Ascii 8 DMC-GX8
Exif.Photo.MakerNote Undefined 28904 (Binary value suppressed)
Exif.MakerNote.Offset Long 1 1320

I don't know now what to do. Please, any help on this?

#7 Updated by Roman Lebedev almost 2 years ago

Rafael Linux User wrote:

Sorry, but after trying to get work my camera/lens asking to exiv2 group and creating ".exiv2" file,

I discovered that Darktable is not recognizing that the camera is a GX8.

darktable or lens correction module (which is lensfun)?

However, exiv2 is showing correctly DMC-GX8, as you can see:

exiv2 -pa _1000731.RW2 | grep -i 'lens\|model\|make'Exif.PanasonicRaw.Make Ascii 10 Panasonic

Exif.PanasonicRaw.Model Ascii 8 DMC-GX8
Exif.Image.Make Ascii 10 Panasonic
Exif.Image.Model Ascii 8 DMC-GX8
Exif.Photo.MakerNote Undefined 28904 (Binary value suppressed)
Exif.MakerNote.Offset Long 1 1320

I don't know now what to do. Please, any help on this?

#8 Updated by Rafael Linux User almost 2 years ago

Sorry, I should explain me bad. I expect that darktable applies some automatic corrections, like "orientation" or "base curve". But "lens correction" is not applied automatically, so I go to "Lens correction module" and the camera combo selector is void and when I click on that combo, nothing happens. In the lens combo, appears "Lumix G Vario 12-35/F2.8" (is not my X Vario, but is not so important), and below this combo, Darktable says "camera/lens didn't find. Please, select it manually".

#9 Updated by Roman Lebedev almost 2 years ago

Rafael Linux User wrote:

"camera/lens didn't find. Please, select it manually".

So lensfun does not know about that camera, report that to lensfun.
https://sourceforge.net/p/lensfun/bugs/ https://github.com/lensfun/lensfun

#10 Updated by Roman Lebedev almost 2 years ago

Rafael Linux User wrote:

Sony A700 with RAW files.

Also, if you still have that camera, please contribute the full sample set, see https://discuss.pixls.us/t/raw-files-opened-in-dt-start-way-off/6272/18?u=lebedevri

#11 Updated by Rafael Linux User almost 2 years ago

I don't know if the problem was lensfun/exiv2/system related, however, Maik Qualmann gave me the solution. He suggested me in Digikam bugs forum, to copy the files from the directory "$HOME/.local/share/lensfun/updates/version_1/" one directory higher. Then, DigiKam and even DarkTable not only detect my GX8, but they show the exact model on the lens mounted.

So really, I don't understand which where was the problem, but the fix from Maik was perfect.

About my previous Sony, I'm sorry, but I sold it 2 months ago.

Thank you any way.

#12 Updated by Roman Lebedev almost 2 years ago

Rafael Linux User wrote:

DarkTable

Why do you all write that all of the sudden?
The only correct spelling is: darktable.

#13 Updated by Rafael Linux User almost 2 years ago

Maybe cause English is not my native language, as you noticed for sure, so I did presume there was not difference. For me, is more understable "DarkTable" (as concatenating words), but I'll try not to rename it's correct spelling ;)

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