Confused - Canon 6D with 24-70mm f/4 IS USM L lens appearing as an APS-C lens in exif data.

Dave Hornby

Suspended / Banned
Messages
1
Name
Dave
Edit My Images
Yes
Hi there. New user, first question!

I've been out and about today with the equipment mentioned above.
Looking at the data after downloading my (not all that impressive) efforts, the lens length is showing as 64mm, even though I know the images I looked at were taken at the full 70mm length of the lens.
The 6D is a full frame body, the lens is designed for it.
What gives? Any suggestions please?
 
Hi there. New user, first question!

I've been out and about today with the equipment mentioned above.
Looking at the data after downloading my (not all that impressive) efforts, the lens length is showing as 64mm, even though I know the images I looked at were taken at the full 70mm length of the lens.
The 6D is a full frame body, the lens is designed for it.
What gives? Any suggestions please?
Can you post the exif data or the picture with exif data.
Incidentally if it had exif data based on APS-C data the lens length reported would, I think, be quoted as 1.6 times the actual length but I'll be honest I though the exif data just reported the actual focal length used to take the shot not the "equivalent" length, I could be wrong though, I'm on FF so I just assumed exif data reported the actual length. It isnt that unusual for lens manufacturers to quote focal length that are slightly incorrect, after all 600mm sounds a whole lot better than 550/560 etc. So maybe your 70mm is actually 64mm.
Matt
 
Last edited:
APS-C 70mm equivalent would be approximately 105mm.

I've seen on a YouTube review that Sigma Art 50mm lens is actually somewhere closer to real 48.5mm focal length. I think 24-70mm focal length could be an approximation too at certain zoom levels. My guess is - works as intended.
 
PS it's also very easy to zoom back slightly from maxed out zoom range so getting 64mm when you thought you were fully zoomed.
 
Hi there. New user, first question!

I've been out and about today with the equipment mentioned above.
Looking at the data after downloading my (not all that impressive) efforts, the lens length is showing as 64mm, even though I know the images I looked at were taken at the full 70mm length of the lens.
The 6D is a full frame body, the lens is designed for it.
What gives? Any suggestions please?

Doesn’t sound out of the ordinary, I’d say working as intended.
 
It's only a few MM difference so would most likely be accurate.

Where is the EFS / APS-C reference in the exif data?
 
It's nothing to do with APS-C as the tag doesn't exist so I expect that what you're seeing is down to one of two possibilities
1). The focal length range (24-70) is specified for the lens when focussed at infinity. As you focus on closer subjects then the maximum focal length reduces (as it does with most modern internal focus lenses).
2) The lens' zoom encoder is not set up quite correctly.

Bob
 
This got me mildly curious. Just fired one off using the same lens on a FF body. Had the lens set to its max focal length and it clearly shows 70mm focal length in the image details.

24-70 test.jpg
 
Back
Top