Problems editing Maker Notes

[Larry McWhorter]

I have a Sigma 18-200 F3.5-6.3 II DC OS HSM which I use on my Pentax K-3.  Its my daily lens and for some reason the Maker Notes LensType reads Unknown (8 33) and DXO PhotoLab which uses maker notes to determine a lens correction module will not read the LensType Correctly it reads all my other Sigma and Tamron and Pentax Lenses correctly.  I am trying to use an argument file saved in a directory along with ExifTool.exe.  I have created a shortcut on my desktop so as to be able to drag and drop my image files that need correction.  Here are the arguments in the txt file  -MakerNotes:LensType=Sigma 18-200 F3.5-6.3 II DC OS HSM  -overwrite_original_in_place  the argument file is named Sigma_18_200.txt   I have appended the Exiftool Shortcut Icon properties to read C:\ExifTool\exiftool(-k).exe -@ Sigma-18-200.txt.  When I drag and drop a DNG file on to the icon ExifTool is invoked and a routine is run but the MakerNotes are not over written.  ExifTool returns this message "0 Image Files Updated" "1 Image File Unchanged".  I tried substituting LensType=8 33 which is the correct numeric designator for my 18-200 still the same response for ExifTool.  Where am I going wrong???

Larry

[Phil Harvey]

Hi Larry,

Could you send me a sample so I can test this myself?  My email is philharvey66 at gmail.com

- Phil

[Larry McWhorter]

A sample DNG?

[Phil Harvey]

Sure.  My mail can take it if yours can.  Otherwise you could upload it to a filesharing server somewhere.

- Phil

[Phil Harvey]

I got the file, thanks.

Very odd.  I was confused because ExifTool should recognize lens type "8 33", and in fact it does (LensType and LensID are correct).  The LensModel, however is written as the literal string "Unknown (8 33)", which is causing your problem.  Perhaps you copied LensID to LensModel using an older version of ExifTool?  It looks to me like this DNG has been edited by ExifTool previously.  To fix this, the following command should work as long as you use a recent version of ExifTool:

exiftool "-lensmodel<lensid" FILE

- Phil

[Larry McWhorter]

Thanks Phil,

I ran a test this morning using my Sigma 70-300 as well as my Sigma 18-200.   For the 70-300 ExifToolGUI reported the correct Lens Type as Sigma Lens (3 255) but still reported the 18-200 as Unknown (8 33).  The EXIF was read straight off the SD card image.  I am using DXO PhotoLab and the program gets its lens data from the Maker Notes LensType so I need to know the proper coding to write the data to LensType in maker notes. 

You are correct about that file being edited by ExifTool, my apologies for sending the wrong DNG file.  I am sending you two files via email from this morning, one file IMGP9118.DNG is a file taken with my 70-300 which reports the correct LensType value of Sigma Lens (3 255) and the second file IMGP9119.DNG which reports the lensType value as Unknown (8 33).  I suspect that my camera firmware is not reporting the proper LenType values. 

Larry

[Phil Harvey]

Hi Larry,

I'll take a look at the new files when I get a chance.  But as I said, LensType "8 33" is known by the current version of ExifTool.  What version are you using?

- Phil

[Larry McWhorter]

Hi Phil the version I am using is 10.6.5.0 to write to the Maker Notes, Lens Type, value.  I'm not too proficient with command line processing and I have been using ExifToolGui  to read the EXIF data.  I discovered that ExifToolGUI was using an outdated version of ExifTool, now I'm getting the proper information from ExifToolGui in the Maker Notes, however, I think DXO PhotoLab is looking for the following in the Maker Notes, Lens Type, value section:  Sigma 18-200 F3.5-6.3 II DC OS HSM because it still will not recognize the lens. I assume Lens ID is the same as what I'm now seeing as lens type in ExifToolGui.  My question is how do I properly write an argument file to reflect the needed text string that would allow the DXO module to read EXIF and render the desired lens module.

Thanks

Larry

[Phil Harvey]

Hi Larry,

The MakerNotes LensType is stored as a numerical value.  There is nothing you can do to help DxO recognize this value.  The only thing you might be able to do is to write EXIF:LensModel, which is stored as a string, so you can write anything you want:

exiftool -lensmodel="Sigma 18-200 F3.5-6.3 II DC OS HSM" FILE

- Phil

[Larry McWhorter]

So maker notes numeric values can not be changed with ExifTool?  I think I have found the correct numeric value for DXO to recognize the lens.  The value is listed in your Pentax Notes info as  "8 27 Sigma 18-200 F3.5-6.3 II DC HSM"  since Pentax lenses aren't stabilized the "OS" is left out of the description.  This particular lens is about four years older than my "8 33" model. Can anything be done with this information?

What I am trying to do is write the arguments to an arguments text file to be placed in the same folder as ExifTool so that ExifTool will reference the arguments text file and execute the arguments when a DNG file is dragged to the ExifTool shortcut. 

What is the proper syntax for an argument placed in a text file

sorry to be such a bother

Thanks

Larry

[Phil Harvey]

Hi Larry,

Sure ExifTool can change the numeric value.  Either this

exiftool -lenstype="Sigma 18-200 F3.5-6.3 II DC HSM" FILE

or

exiftool -n -lenstype="8 27" FILE

should work.

The argument file would be

Code Select Expand

-n
-lenstype=8 27

- Phil

[Larry McWhorter]

Thanks Phil,

That worked like a charm!  DXO recognized the photo and applied the module!  Now I need to start dragging and dropping files!

Many Many thanks

Larry