
Message: 9         
   Date: Tue, 19 Jul 2005 05:52:36 -0000
   From: "n5kzw" <n5kzw@arrl.net>
Subject: EXIF Comparison (Apples & Apples)

Renato, I called it Apples & Oranges because I was comparing the
d70reader output from a .nef file to the IEXIF output from a .jpg
file.  I couldn't be sure whether the differences I was seeing were
due to the readers or the .jpg conversion.

This morning I took a shot in RAW+BASIC mode.  I also ran the .nef
file through Nikon Capture to generate a second .jpg file.  I then
used d70reader and IEXIF to look at the files (.jpg only for IEXIF). 
The total results are in an EXCEL file in the FILES section named
"EXIF Fields.xls".

The interesting (to me) finds were:
1.  d70reader reports the maximum lens aperature as "5", while IEXIF
reports it (correctly) as 5.6.

2.  Nikon Capture apparently tosses the Flash Setting data when saving
a .jpg file.

3.  d70reader does not report any Flash Compensation data for a .jpg
file saved by Nikon Capture, but IEXIF does.

4.  d70reader correctly reports the Lens Type as "G" while IEXIF
reports it as "Nikon Series D Lens".

5. d70reader does not return a value for ColorSpace and 4 other
fields) in .nef files that are found in .jpg files.  This could be
because the data is only valid for .jpg files, I don't know.

6.  When saving a .jpg file, Nikon Capture does not save data for
about a dozen fields that are saved in a BASIC .jpg file.

7.  IEXIF reports about 18 fields more than d70 (with all fields
enabled in the d70reader configuration file).  Admittedly none of the
fields are particularly useful and some of them may be fields that are
being reported by d70reader under different field names.

I chose these two programs to compare as they both seemed to report a
lot EXIF information.  d70reader is the best of the two for printing
the EXIF information, but it looks like IEXIF has the edge in  ease of
use and accuracy (except for the Lens Type).  CTL-A does not work in
IEXIF, so screen captures are the only way to print the output.

Regards,
Ed


