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Old August 3rd, 2006, 12:47 PM
Peter Ruevski Peter Ruevski is offline
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Join Date: Jul 2006
Posts: 39
Default Fun with ExifTool, mystery partially solved

Hi all,

So after Mike’s revelation that it might be the lens I just had to go back and check my combed photos. Being a geek - and lazy - I decided that it is too much work to do it by hand so I downloaded ExifTool by Phil Harvey (http://www.sno.phy.queensu.ca/~phil/exiftool/). What can I say… it is the mother of all EXIF utilities; the BFG of meta-data extraction; the Pan Galactic Gargle Blaster of EXIF tools;

the…
One Tool to rule them all, One Tool to find them,
One Tool to bring them all and in the darkness bind them

Did I mention I was impressed? :-) This thing will suck the last bit of metadata out of whatever image file you throw at it!

To make a long story short - after installing Perl; figuring out which of the endless ExifTool options will dump the data (from 775 raw files 215 of wich combed) the way I wanted it; some more batch files and some tinkering in Excel I can say this:

The combing is caused either by the lens, or a combination of the lens and a small aperture. ISO speed, shutter and exposure compensation do not matter it seems. My EF50mm f/1.8 and EF100mm f/2 USM "comb" quite often. My other lenses never do.

I have updated the web page with the full statistics and detailed conclusions as well as some of Mike’s combed 5D photos with the EF50mm f/1.4 USM. Look at the bottom.
http://www.pages.drexel.edu/~par24/r...histogram.html

Best regards,
Peter

Last edited by Peter Ruevski; August 3rd, 2006 at 12:54 PM.
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