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04-23-2019, 07:10 AM   #1
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Focal length sensor on the Tamron 17-50?

Hello,

I noticed recently that my Tamron 17-50 no longer reports correct focal length in EXIF. It's always 45mm no matter what real focal length I choose. I don't know since when did it happen, but I suspect something is wrong with the "focal length sensor" of the lens. This error, in my knowledge, doesn't really affect the operation of the lens, except for in-body stabilization since the camera no longer knows the true focal length, however in term of photos organization it's quite annoying since I can no longer sort my photos by focal length, therefore and I'm wondering whether I can fix it.

With my 50-135, for example (which also had that problem before), I can find the metal piece that was responsible for focal length detection right under the zoom ring rubber band. This time, I got no luck after rolling out the zoom rubber band of the Tamron, since nothing is under it.

Do you have any idea where I can find this thing without too many disassembly activities? I'm quite clumsy and whenever I try to open up a lens I risk damaging it :-)

Thank you.

04-23-2019, 07:55 AM   #2
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I assume you have tried cleaning all the contacts on lens and mount?

When you first turn on the camera does it prompt you for a manual focal length input for the SR ?
04-23-2019, 08:17 AM   #3
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QuoteOriginally posted by Bui Quote
Do you have any idea where I can find this thing without too many disassembly activities? I'm quite clumsy and whenever I try to open up a lens I risk damaging it :-)
How it is done varies by lens and usually would involve disassembly to access. A greater concern might be whether there is physical damage to the lens somewhere.


Steve
04-24-2019, 01:51 AM   #4
Bui
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QuoteOriginally posted by pschlute Quote
I assume you have tried cleaning all the contacts on lens and mount?

When you first turn on the camera does it prompt you for a manual focal length input for the SR ?
I already tried cleaning all contacts, both on the lens and on the camera. It doesn't ask for a focal length when I turn it on, I guess for some reasons, the focal length is always reported as 45mm.

---------- Post added 04-24-19 at 01:52 AM ----------

QuoteOriginally posted by stevebrot Quote
How it is done varies by lens and usually would involve disassembly to access. A greater concern might be whether there is physical damage to the lens somewhere.


Steve
Could be, but I don't remember any incident happened with it, and from the look, it's like new.

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