Changing black level tag on .dng file

[liukis]

Hello,
I am on Mac and trying to change a Black Level tag on .dng file.
First I type: exiftool -h M23-1159_C0000_00411.dng
I get this information: <tr><td>Black Level</td><td>2047</td></tr>
Then I run: exiftool -Black Level=2048 M23-1159_C0000_00411.dng
I get following message:
File not found: Level=2048
======== M23-1159_C0000_00411.dng
    1 image files read
    1 files could not be read
What am I doing wrong? Can somebody please help me to change the Black Level on .dng file?
Thanks,
Richard Liukis

[ryerman]

Tag names have no spaces.
Try -BlackLevel=2048

And for future reference, file and folder names and paths must be in quotes if they contain spaces. Use single quotes on a Mac and double quotes with Windows.

[liukis]

When I try: exiftool -BlackLevel=2048 M23-1159_C0000_00411.dng
I get:
0 image files updated
1 image files unchanged

When I try: exiftool "-Black Level=2048" M23-1159_C0000_00411.dng
I get:
Warning: Tag 'Black' does not exist
Nothing to do.

When I try: exiftool "-BlackLevel=2048" M23-1159_C0000_00411.dng
0 image files updated
1 image files unchanged

I would really appreciate your help.

[Phil Harvey]

Use the -v2 option to see what is happening:

Code Select Expand

> exiftool -blacklevel=2048 -v2 image.dng
Writing SubIFD:BlackLevel
...


BlackLevel is written to SubIFD by default.  Nothing will happen if the DNG doesn't contain a SubIFD.

Use this command to figure out where BlackLevel is stored:

exiftool -G1 -blacklevel image.dng

then write it to the same place:

exiftool -GROUP:BlackLevel=2048 image.dng

- Phil

[liukis]

Dear Phil,

Thank you so very much. It worked. I really appreciate your help. It is a well written tool.

Richard Liukis