Canon 24mm f3.5 tilt-shift - ebay return request

jerry12953

jerry12953

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Jeremy Moore
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I bought one 2nd hand last summer and used it a few times with seemingly OK results. However I decided to move it on and I have now had a return request from ebay, with the following explanation -

Aperture only opens to f:4 and not to f:3.5 as it should. EXIF data shows the lens is a 17mm which is incorrect. (the Canon 17mm TS-E is a f:4). This 24mm had likely been repaired with 17mm parts - some components are common to both lenses. This will cause problems when trying to stitch photos together as the software won t function correctly if it thinks the photos were taken at 17mm.

This doesn't make much sense to me. Is the buyer just trying it on?

 
Do you still have any images taken with it that you can check the exif?
 
Did you buy it from a dealer or was it a private sale?
 
jerry12953 said:
Private unfortunately. But the previous owner had had it repaired by Fixation just prior to selling it. 22nd June last year......:(
Click to expand...

Well worth raising the issue with him, especially as in this case Fixation did a repair.
 
The Exif tag for the TS-E 24/3.5 is"95" whilst that of the TS-E17/4 is "94".......swap the least significant bit and the 24mm becomes the 17mm as far as the body is concerned and that's a more likely scenario than the wrong parts having been used.
I suspect that the lens can be reprogrammed to reflect its true status.

Bob
 
Canon Bob said:
The Exif tag for the TS-E 24/3.5 is"95" whilst that of the TS-E17/4 is "94".......swap the least significant bit and the 24mm becomes the 17mm as far as the body is concerned and that's a more likely scenario than the wrong parts having been used.
I suspect that the lens can be reprogrammed to reflect its true status.

Bob
Click to expand...

Bob,

That sounds really useful and interesting but I don't really understand it. Any chance you could elaborate?
 
Each lens has a binary coded embedded so that the body is able to understand what's it's "wearing". The code is transferred during the initial communication and the body then controls accordingly. There is only one binary bit different between the two lenses and I'm hypothesising that this bit is miissing in the coded message/internal lens id. I would expect that a Canon service centre can reprogramme the lens to reflect its true type.

Bob
 
Canon Bob said:
Each lens has a binary coded embedded so that the body is able to understand what's it's "wearing". The code is transferred during the initial communication and the body then controls accordingly. There is only one binary bit different between the two lenses and I'm hypothesising that this bit is miissing in the coded message/internal lens id. I would expect that a Canon service centre can reprogramme the lens to reflect its true type.

Bob
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That really is useful to know, Bob. I'm very grateful.
 
Bob,

i've just phoned Fixation and they have looked into it. While the 24 mm lens does share some parts with the 17mm, it looks like when they repaired it just before I bought it they probably programmed it incorrectly. They have offered to reprogramme it FoC. :)

Many thanks again.
 
jerry12953 said:
Bob,

i've just phoned Fixation and they have looked into it. While the 24 mm lens does share some parts with the 17mm, it looks like when they repaired it just before I bought it they probably programmed it incorrectly. They have offered to reprogramme it FoC. :)

Many thanks again.
Click to expand...

Great result ... thumbs up to Canon Bob (y)
 
jerry12953 said:
Bob,

i've just phoned Fixation and they have looked into it. While the 24 mm lens does share some parts with the 17mm, it looks like when they repaired it just before I bought it they probably programmed it incorrectly. They have offered to reprogramme it FoC. :)

Many thanks again.
Click to expand...
That's good news, Jerry, and a gold star for Fixation for accepting their error (or potential error).

Bob
 
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