Editing Lens ID?

[sam_553817]

Hi,

My Tamron 28-75mm, used on a Sony a850, has (according to your Sony Tags page) a LensType tag of 24.6 which explains why it is showing up as " Minolta/Sony AF 24-105mm F3.5-4.5 (D) or Sigma or Tamron Lens ", which is LensType 24.  This is very annoying as DXO Optics won't let me apply the correction profile for the Minolta/Sony 28-75mm, all of which are more or less the same lens.  The LensType for the Minolta 28-75mm is 39.  Is there a way to change just this tag from 24.6 to 39?  Can it be done in a shortcut or do I need to use the command interface, and how do I do either?  I've read the documentation but I'm just not that knowledgable with this sort of thing.  Will changing just this tag fix this?

Thanks,
Sam.

[Phil Harvey]

Hi Sam,

It doesn't hurt to try:

exiftool -n -lenstype=39 FILE

or

exiftool -lenstype="Minolta AF 28-75mm F2.8 (D)" FILE

- Phil

[sam_553817]

Hi Phil,

Thanks for the quick reply.  That worked for changing the EXIF, DxO is happy but the images now open up in Lightroom with a pink colour cast?  ANy ideas on that?

[sam_553817]

Forgot to mention, I get a message saying:

"Warning: [minor] Entries in SubIFD were out of sequence. Fixed."

[sam_553817]

Comparing the exif of the modified and original files, the following changes have been made:

Original:  JpgFromRawStart: 155683
Modified: JpgFromRawStart: 98388

Original:  LensID: Sigma 18-50mm F2.8 or Sigma 20-40mm F2.8 EX DG Aspherical IF or Tamron SP AF 28-75mm F2.8 XR Di (IF) Macro
Modified: LensID: Minolta AF 28-75mm F2.8 (D)

Original:  LensType: Minolta/Sony AF 24-105mm F3.5-4.5 (D) or Sigma or Tamron Lens
Modified: LensType: Minolta AF 28-75mm F2.8 (D)

Original:  SR2SubIFDLength: 53248
Modified: SR2SubIFDLength: 53068

Original:  SR2SubIFDOffset: 36528
Modified: SR2SubIFDOffset: 41564

Original:  StripOffsets: 688128
Modified: StripOffsets: 608598

Original:  ThumbnailOffset: 32770
Modified: ThumbnailOffset: 94822

Does that help at all?  Sorry for all the q's.

Thanks,
Sam.

[Phil Harvey]

Yes.  This is a bug in Lightroom that has not yet been fixed (although I reported it to them back in January).  See the Known Problems section on the ExifTool home page for details.

It is somewhat ironic that DxO reads the edited NEF alright, but Lightroom doesn't because I have read a statement from one of the DxO programmers that said they only support reading of original RAW images.

- Phil

[sam_553817]

Thats annoying!

May have found a work around though, converting to dng first, then editing exif with the following:

exiftool -n -lenstype=39 -lens="Minolta AF 28-75mm F2.8 (D)" -lensinfo="28/1 75/1 28/10 28/10" -dnglensinfo="28/1 75/1 28/10 28/10" c:\users\sam\desktop\26

But with this I get a warning saying:

"Waring: Not a floating point number for ExifIFD:LensInfo
Waring: Not a floating point number for IFD0:DNGLensInfo"

It still changes the LensInfo tag to "28/1 75/1 28/10 28/10", but not the DNGLensInfo tag, which stays as "24-105mm f/3.5-4.5"

If I use exiftool -n -dnglensinfo= -lenstype=39 -lens="Minolta AF 28-75mm F2.8 (D)" -lensinfo="28/1 75/1 28/10 28/10" c:\users\sam\desktop\26

then I can just get rid of the tag, but I'd rather not do that.

What I am doing wrong here with the LensInfo and DNGLensInfo?

[Phil Harvey]

Both DNGLensInfo and LensInfo are converted the same way (so it shouldn't be writing LensInfo either as you suggested).  With the -n option, they expect 4 floating point numbers, ie. "28 75 2.8 2.8", as mentioned in the EXIF tag name documentation.

- Phil

[edit] Be sure you are using a recent version of ExifTool (8.17 or later, since the LensInfo conversions were improved in that version).

[sam_553817]

thanks for all your help.