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jdirelan87
10-05-2006, 01:44 PM
I was just browsing through some of my shots and noticed something strange. With my 75-300 lens I almost without expection shoot at f/8. However, according to the EXIF datated, the computed f stop is something like f/4.1 or f/4.4 even thought I know I shot it at f/8. Anybody know what is up with this?

fullreversal
10-17-2006, 12:49 AM
http://www.railpictures.net/forums/showthread.php?t=4068

Mgoldman
10-17-2006, 04:34 AM
Slightly off the topic, but anyone working for the EXIF man -
what's with a Shutter Speed listing as 2/1000 verus a simpler
1/500th? And why not an apeture simply stated as 8 or 16?

/Mitch

alan-crotty
10-17-2006, 11:48 AM
John,

Check out the contacts between the camera and lens, I had some issues last month where the EXIF showed the wrong focal length, I cleaned the contacts on the lens and all was ok.

Alan

alan-crotty
10-17-2006, 11:50 AM
Hi Mitch,

The EXIF data (as you know) is computer produced and you expect it to be sensible! :grin:

Alan

Mgoldman
10-18-2006, 12:09 AM
Hi Mitch,

The EXIF data (as you know) is computer produced and you expect it to be sensible! :grin:

Alan

You mean that applies to all computer produced output??? I thought it was specific to Microsoft!

/Mitch

Islander
11-05-2006, 02:33 PM
With my 75-300 lens I almost without expection shoot at f/8. However, according to the EXIF datated, the computed f stop is something like f/4.1 or f/4.4 even thought I know I shot it at f/8.

Perhaps this comes close.
Looking back through some of mine, it appears to be the max apature for the lens at the focal length of the shot. So on your 75-300 it would probably be between 4 and 5.6 (just guessing).
This may be the starting point the camera "computed" the exposure from.
I wonder what it would say if you used an old manual lens that doesn't communicate. Could anyone point out an EXIF like that?

alan-crotty
11-05-2006, 04:33 PM
I was just browsing through some of my shots and noticed something strange. With my 75-300 lens I almost without expection shoot at f/8. However, according to the EXIF datated, the computed f stop is something like f/4.1 or f/4.4 even thought I know I shot it at f/8. Anybody know what is up with this?


I have had this problem with my 100-400 lens, it reported the wrong focal length. :confused:

The cure, clean the contacts on the lens an camera, the result good data. :D

Alan