Focus way way off

jamin-b

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Jul 20, 2013
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What does it mean when a lens' focus is so way off that it can't focus beyond a few meters?

I just received a Supper Rokkor 50mm F2 LTM lens that is in decent shape but with great optics. I took it out for a test on my Nex 7 with an LTM adapter I use and the photos are truly sharp, contrasty and with an interesting rendering BUT, then I realized that for close portraits the lens was showing a distance near 30ft - infinity. Thinking it might be the adapter, I slipped it onto my M8 with a LTM to M adapter, and indeed the focus is way way off. I've read about slight incompatibility between rangefinder and lens but this is off the charts, and basically means the lens is unusable (1) on a rangefinder or (2) on a mirrorless beyond say 3m. Is this something even worth considering for repair (which may mean self-repair)? Or do i just ship it back? Appreciate your thoughts...

I do like the look of his lens a lot:

https://www.flickr.com/photos/96319283@N08/17224066502/

https://www.flickr.com/photos/96319283@N08/17039601419/in/photostream/

<a href="https://www.flickr.com/photos/96319283@N08/17224066502" title="super rokkor 50mm f2 ltm -9 by Ben Sandler, on Flickr"><img src="https://farm8.staticflickr.com/7615/17224066502_5e020a3ddc.jpg" width="500" height="500" alt="super rokkor 50mm f2 ltm -9"></a>

<iframe src="https://www.flickr.com/photos/96319283@N08/17224066502/player/" width="500" height="500" frameborder="0" allowfullscreen webkitallowfullscreen mozallowfullscreen oallowfullscreen msallowfullscreen></iframe>
 
If the glass is clean and you like the lens, have it repaired. Unless you paid over 200 for it. Then send it back. Don't try to do it yourself, somebody already did that, and ran into a problem. I've only had one, 5cm 2.8 but it seemed like it was was pretty tightly put together. I wasn't going to try taking it apart. You have an expensive hobby, lenses matter so put your money there..
 
Well if the lens has produced sharp images under certain conditions it is probably safe to assume the optical components are up to scratch. It sounds to me like someone may have stripped it and re-assembled it at the wrong start on the helical thread, or incorrectly assembled other parts such as the distance scale ring and perhaps, hence, where it stops at infinity. Not having any first hand experience with this lens, I can't offer more specific suggestions. If you're reasonably handy with repairs and have the patience you may be able to correct this but only you know your skill levels etc.
Cheers
Brett
 
Thanks for replies - seller has agreed to take it back for a repair or refund, so either way should be fine. It does have very nice optics, and at $150 was reasonably priced. I think it would make a great lens for a vintage color look, but may be "too" contrasty for the type of black and white photography I like.

The more I dabble in the older lenses the more I prefer them over more modern alternatives, such as CV lenses, that are truly well made and for my needs beyond reproach, but somehow seem to lack a certain spark...
 
Lenses are definitely magic. Keep it! Your other options for this focal length/speed are the canon, the jupiter, and the rest go up in price quickly.

:)
 
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