Some Tags values are not shown

[siamak]

I am using Exiftool 8.17 on mac 10.6. and Image files are NEF Software 1.0 Nikon D50
when I use exiftool filename all tags values are return including the below tags. Yet when tags specifically selected values are not returned.
these are the only tags so far I have problem:
WBRGGB Levels
Depth Of Field
Field Of View
using flag -f with these tags also return "-"

[Phil Harvey]

It sounds like you may be confused between tag names and descriptions.  If so, I think reading FAQ number 2 may help.

Please let me know if this doesn't solve the problem.

- Phil

[siamak]

thanks.
my mistake, I assumed tags name are same as description but without spaces between the words.
It may be true on some tags but not for all the tags.(e.g. FOV not FieldOfView)