Author Topic: White balance problem in Capture One PRO as a result of writing IPTC data  (Read 8824 times)

Offline crunge

  • Newcomer
  • *
  • Posts: 12
    • View Profile
I have an interesting problem that I need assistance with. Sorry for the long post, but it is complicated.

I was starting a workflow that consisted, in brief, of the following:
(1) Ingest photos from CF card into Photo Mechanic, renaming and applying basic IPTC data (note that IPTC/XMP preferences were at their defaults)
(2) Further apply IPTC tags
(3) Convert selected RAW files using Capture One PRO 3.7.4

At this stage I noticed a number of problems with white balance in C1Pro. These included: incorrect white balance information, selecting "As Shot" white balance changing the white balance to 4750K and -200 tint for every image (really bad), and white balance changes not being kept across C1Pro program restarts.

So I reported the problem to Phase One, thinking it their problem.

However, I discovered through trial and error that photos from the same camera that have not had IPTC information applied using PM do not exhibit this problem.

I've discovered that for future imports I need to disable adding the IPTC-NAA resource (in PM) when writing IPTC. When I do this I can still apply IPTC info in PM and C1Pro works as it should.

But I have problem with a large number of photos that had IPTC information applied where adding the IPTC-NAA resource was selected. I need to recover these to a state where C1Pro doesn't have the WB issues. I can do this to a certain extent by selecting "Revert TIFF-based RAW to Original" in PM. If I do this then the images are stripped of their IPTC information and C1Pro works as it should with white balance. But as soon as I try to re-write any IPTC data (even with adding the IPTC-NAA resource deselected in the Preferences panel) the problem reoccurs, whereas newer images that never had the IPTC-NAA resource added work fine. Even clearing the resource fork on the problem images doesn't solve the problem. For some reason if the add IPTC-NAA resource option was ever enabled on an image I can't get it back to a state where I can write IPTC information and have C1Pro still work with the white balance correctly.

Here's like I desperately need: a way to revert these problem images to a state where I can add IPTC information and have C1Pro read it, without white balance problems.

The camera is a Nikon D2x (I'm not sure how much this matters).

PM version is 4.4.3

P.S. I would have never thought that writing IPTC information such as copyright, keywords, etc. would affect white balance. Very strange!

Offline crunge

  • Newcomer
  • *
  • Posts: 12
    • View Profile
My apologies for some misleading information posted thus far.

After some additional testing it appears that, in my case, the problem is exclusively caused by (1) using Auto White Balance and (2) writing IPTC data of any form (outside of an XMP sidecar file that isn't picked up by Capture One PRO anyway) to the raw file.

To test this I shot the the same image three times with three different WB settings, the first one Auto. I then applied IPTC data to all three images and then brought them into Capture One PRO. The image with Auto WB had the problem; the other two (one shot with Sunny and the other with Cloudy +3) didn't.

I still have the challenge of what to do with all of the Auto WB images that I already imported and tagged with IPTC data using PM.

Offline Kirk Baker

  • Senior Software Engineer
  • Camera Bits Staff
  • Superhero Member
  • *****
  • Posts: 22681
    • View Profile
    • Camera Bits, Inc.
My apologies for some misleading information posted thus far.

After some additional testing it appears that, in my case, the problem is exclusively caused by (1) using Auto White Balance and (2) writing IPTC data of any form (outside of an XMP sidecar file that isn't picked up by Capture One PRO anyway) to the raw file.

To test this I shot the the same image three times with three different WB settings, the first one Auto. I then applied IPTC data to all three images and then brought them into Capture One PRO. The image with Auto WB had the problem; the other two (one shot with Sunny and the other with Cloudy +3) didn't.

I still have the challenge of what to do with all of the Auto WB images that I already imported and tagged with IPTC data using PM.

It sounds like C1 Pro doesn't parse your RAW files properly and is expecting certain data to be in an exact location.  They likely need to fix their parser.  You ought to send them some samples for them to use to fix their parser.

-Kirk

Offline oreixa

  • Newcomer
  • *
  • Posts: 15
    • View Profile
    • www.rallyes.net
Nikon D2x white balance is proprietary, thus C1 and other have to do reverse engineering to get the WB. If you use Nikon's software get the same problem?


Offline dennis

  • President
  • Camera Bits Staff
  • Sr. Member
  • *****
  • Posts: 429
    • View Profile
    • Camera Bits, Inc.
Chris,

If you need to embed IPTC/XMP data INTO a RAW file (rather than use an XMP sidecar), then Photo Mechanic needs to relocate the TIFF table so it can insert the IPTC and/or XMP tag(s).  Some software cannot properly parse these modified RAW files even though they logically follow the TIFF spec.  That is why we added the Revert TIFF based RAW files tool which restore RAW files to their original state (although there may still be Photo Mechanic preferences appended to the end of file).

I suspect that C1 is using some software from Nikon (called a "mini SDK") for reading the encrypted white balance for the D2X (and D2Hs etc), and because of the way this software was written it cannot propery parse the modified TIFF file.  We identified this problem when 4.4 was released and notified Nikon about the problem since it was affecting the Adobe ACR plug-in as well.  There is a very simple workaround to make this work and Adobe has fixed their ACR plug-in as we suggested (which is to simply patch the IFD table pointer to its original offset of 8 after the first part of the NEF file is read into memory and before handing this off to Nikon's mini SDK).  If C1 isn't using Nikon's mini SDK then they just need to fix their own parsing to allow for the TIFF table to be anywhere in the file.

Hope that helps!

--dennis

Offline crunge

  • Newcomer
  • *
  • Posts: 12
    • View Profile
Thanks for all of the replies. As of Capture One Pro 3.7.3, it supports the Nikon encrypted WB (I don't know the implementation being used) but it does appear C1Pro still has a problem with Auto WB (at least when changes are made to the NEF). I'm working in parallel with Phase One to find a solution to this problem and will pass along the information that Dennis provided.

As I look at this more and more, I agree this is less of a PM problem and more of a C1 problem since Nikon Capture and Adobe Camera Raw do not have problems processing the same files.