Decreasing numerical tags

[herb]

Hallo Phil,

with version 8.61 of ExifTool you introduced the new feature that allows to increase and to decrease numerical tags.
Thanks for this feature.

I played with it, selected (accidentically) FNumber for my tests and found the following:
   exiftool -exif:fnumber+=-3.0 d:\t1.jpg
   Warning: Must be a positive number for FNumber - d:/t1.jpg
       1 image files updated

In my case ExifTool really decreased the value from 8.0 to 5.0, but the warning could be misunderstood.
I suggest that this warning is always given in case of decreasing a number (with a negative value).
This is done also in cases where the resultvalue is a valid positive value.
Is this an error?

Thanks in advance
Herb

[Phil Harvey]

Hi Herb,

Yes, thanks.  This looks like a bug in my validation.  I'll fix this.

- Phil

[herb]

Hello Phil,

thanks for the correction in version 8.62.

Best regards
Herb