[Originally posted by bogdan on 2008-07-27 15:11:10-07]
Hi Phil,
It's about Makernotes tag 0x0101 -ExposureLevelIncrements (for Canon 450D).
If on camera, EVinc stepping is set to 1/3 (but no exposure comp. is used!), then
exiftool -Makernotes:ExposureLevelIncrements xxx.CR2
-gives:
Exposure Level Increments =1/3-stop set, 1/3-stop comp.
Resulting tag has value 0 (zero) and first part ("1/3-stop set") is correct. I'm not sure what second part ("1/3-stop comp.") mean... because, as said, when taking photo, actual exposure compensation was set to zero (not used).
Now I've changed EVinc stepping to 1/2 and again, no exposure compensation was used when taking photo. Now exiftool shows:
Exposure Level Increments =1-stop set, 1/3-stop comp.
Resulting tag has value 1 (one) and the first part should be "1/2-stop set" ("/2" is missing). Again, meaning of second part ("1/3-stop comp.") is unknown for me.
And another (but related) question:
exiftool -Makernotes:ExposureLevelIncrements xxx.CR2
-gives results shown above.
But using:
exiftool -Canon:ExposureLevelIncrements xxx.CR2
-gives nothing(?). Can you explain, please? Thank you :-)
Greetings,
Bogdan
PS: Using exiftool v7.37
[Originally posted by exiftool on 2008-07-27 15:39:49-07]
Hi Bogdan,
It appears that Canon changed the definition of some
custom functions for the 450D. I will look into this.
For other models, the custom function sets the
exposure increments for setting Tv, Av, etc
(the "X-stop set"), separately from the increments
used when applying exposure compensation
(the "X-stop comp"). So even if you don't apply
exposure compensation, the "X-stop comp" will
be non-zero. But perhaps the wording is different
in the 450D owners manual. I will have to download
the manual and update the custom functions
accordingly.
All custom functions are in the CanonCustom family
1 group, so use -CanonCustom:ExposureLevelIncrements,
not -Canon:ExposureLevelIncrements.
- Phil