Project

General

Profile

Bug #11131

Nikon D7000 multi-exposure raw handling

Added by Zoltan Balogh almost 3 years ago. Updated almost 3 years ago.

Status:
New
Priority:
Low
Assignee:
-
Category:
General
Target version:
-
Start date:
08/27/2016
Due date:
% Done:

0%

Estimated time:
2.00 h
Affected Version:
2.0.5
System:
all
bitness:
64-bit
hardware architecture:
amd64/x86

Description

Hi,

I'm a developer but never worked with imaging products. I found an interesting bug in the Ubuntu Unstable PPA packaged version (by Pascal de Bruijn) of Darktable. (I'm using Ubuntu 16.04.)

My guess without looking at the issue any further other than opening this ticket is that there's a linking problem/difference between whatever RAW-handling library is used between lighttable and darkroom modes? Maybe one of the libraries/versions cannot handle the multi-exposure Nikon D7000 RAW file I'm trying to edit?

I suspect building everything from source and linking dependencies manually would possibly fix the issue and possibly this error only exists in Pascal's package?

It would take me a few hours of reading the code as well as building everything manually to verify if my suspicions are correct, so I cannot tell at this point whether this is Pascal's problem or a problem with your code.

Maybe someone who has a fresh dev build of the product could verify this for me? Attached are JPEGs of the symptoms and the RAW file.

Then I can see if I need to open a different ticket against the Ubuntu PPA?

Much appreciated,

Zoltan

(Looks like for example RawTherapee handles the RAW file OK both for opening and exporting so there are libraries available that could fix this issue.)

dt2.jpg (63.2 KB) dt2.jpg Zoltan Balogh, 08/27/2016 10:30 AM
dt.jpg (60.6 KB) dt.jpg Zoltan Balogh, 08/27/2016 10:30 AM
_DSC2761.NEF (17.4 MB) _DSC2761.NEF Zoltan Balogh, 08/27/2016 10:40 AM

Related issues

Related to darktable - Camera Support #11241: Pentax K-70 multi exposure rawNew10/16/2016

History

#1 Updated by Roman Lebedev almost 3 years ago

  • System changed from Ubuntu to all
  • Target version deleted (Candidate for next minor release)
  • Category changed from Darkroom to General
  • Subject changed from Nikon D7000 multi-exposure raw handling broken --> RAW library linking problem? to Nikon D7000 multi-exposure raw handling

Zoltan Balogh wrote:

Hi,

Hi.

I'm a developer but never worked with imaging products. I found an interesting bug in the Ubuntu Unstable PPA packaged version (by Pascal de Bruijn) of Darktable. (I'm using Ubuntu 16.04.)

My guess without looking at the issue any further other than opening this ticket is that there's a linking problem/difference between whatever RAW-handling library is used between lighttable and darkroom modes?

No.
In lighttable you are seeing the thumbnail, embedded by camera.
In darkroom - darktable tried to load the image, and for some reason it did not bailout in process.

Maybe one of the libraries/versions cannot handle the multi-exposure Nikon D7000 RAW file I'm trying to edit?

Nikon multi-exposure raw is not supported in the first place, so this is not a bug.
However, we should either not load that completely, or load only one of the exposures? (did not look at the image yet)

I suspect building everything from source and linking dependencies manually would possibly fix the issue and possibly this error only exists in Pascal's package?

No, and no.

It would take me a few hours of reading the code as well as building everything manually to verify if my suspicions are correct, so I cannot tell at this point whether this is Pascal's problem or a problem with your code.

Maybe someone who has a fresh dev build of the product could verify this for me? Attached are JPEGs of the symptoms and the RAW file.

I don't remember any changes that would fix this, so i'm pretty sure this is still valid for git master.

Then I can see if I need to open a different ticket against the Ubuntu PPA?

No need, this is the right place.

Much appreciated,

Zoltan

Roman.

(Looks like for example RawTherapee handles the RAW file OK both for opening and exporting so there are libraries available that could fix this issue.)

#2 Updated by Ralf Brown almost 3 years ago

It's just an incorrrect white balance. As near as I can tell, the camera is "baking in" the white-balance multiplication while it's doing the other data manipulation to merge the multiple exposures. If you set the RGB multipliers to 1/1/1 in the White Balance iop, you get correct color.

Looking at the ExIF, it appears that software which correctly displays multi-exposure NEFs is using the RedBalance and BlueBalance values instead of the Red/Blue components of WB_RBLevels. On a regular NEF, these have identical values, but on the multi-exposure NEF, RedBalance and BlueBalance are 1.0.

#3 Updated by Zoltan Balogh almost 3 years ago

Hi Ralf,

I can confirm that your observation about the white balance is indeed correct. Is it worth seeing how other Nikon cameras store this information? I could have access to a D700 soon if that helps. Cheers

#4 Updated by Ralf Brown almost 3 years ago

I just tested on my D7200, and the multi-exposure NEF displays correctly by default.

Checking the ExIF, not only are RedBalance and BlueBalance 1.0 for the multi-exposure image, so are the red and blue components of WB_RBLevels.

Single-exposure image:
WB_RBLevels: 2.08203125 2.89453125 1 1
BlueBalance: 2.894531
RedBalance: 2.082031

Multi-exposure under same lighting:
WB_RBLevels: 1 1 1 1
BlueBalance: 1
RedBalance: 1

#5 Updated by Roman Lebedev almost 3 years ago

Ralf Brown wrote:

I just tested on my D7200, and the multi-exposure NEF displays correctly by default.

Doing very different things in every different version/model seems like the modus operandi for nikon, nothing surprizing.

Checking the ExIF, not only are RedBalance and BlueBalance 1.0 for the multi-exposure image, so are the red and blue components of WB_RBLevels.

Single-exposure image:
WB_RBLevels: 2.08203125 2.89453125 1 1
BlueBalance: 2.894531
RedBalance: 2.082031

Multi-exposure under same lighting:
WB_RBLevels: 1 1 1 1
BlueBalance: 1
RedBalance: 1

#6 Updated by Zoltan Balogh almost 3 years ago

So are you guys going to add special rules for the D7000? Thank you very much for looking at this.

#7 Updated by Ralf Brown almost 3 years ago

Roman Lebedev wrote:

Doing very different things in every different version/model seems like the modus operandi for nikon, nothing surprizing.

In this case, it looks to me more like a bug in the D7000 that silently got fixed in later models (since the white-balance multipliers needed to render the data correctly are in fact 1/1/1 rather than what is stored in WB_RBLevels by the D7000). It would be interesting to see how the D7100 stores the info.

#8 Updated by Roman Lebedev almost 3 years ago

Ralf Brown wrote:

Roman Lebedev wrote:

Doing very different things in every different version/model seems like the modus operandi for nikon, nothing surprizing.

In this case, it looks to me more like a bug in the D7000 that silently got fixed in later models

That would not be surprising even a little bit.

(since the white-balance multipliers needed to render the data correctly are in fact 1/1/1 rather than what is stored in WB_RBLevels by the D7000). It would be interesting to see how the D7100 stores the info.

#9 Updated by Roman Lebedev almost 3 years ago

Also available in: Atom PDF

Go to top