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07-07-2007, 07:34 PM   #1
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Join Date: Apr 2007
Location: Gainesville, Fl
Posts: 103
no infinity focus?

So, I bought a Pentax F SMC Zoom 1:3.5-4.5 35-70 lens from a user on here. I love it! Finally, an auto focus lens! (everything else I use is MF) But, I noticed something after taking some shots with it: if I zoom past about 50mm, I lose infinity focus. Any further away than few feet becomes very soft. So in essense, I have a 35-50mm zoom lens. Why is this? All of my Ricoh glass from Sears is sharp, the $25 mystery lens from B&H is sharp (it's a Dejur...) and the only other lense I don't have infinity focus on is my 500mm Five Star M42, and that's because the screwmount to K adaptor isn't one of those that mounts flush to the body.

I'd really like to be able to use this lens, but if everything is so extremely soft, it's practically pointless. Can anyone help, or should I try to recoup the $40 I paid for the lens?

07-09-2007, 04:46 PM   #2
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Join Date: May 2007
Location: Singapore
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From your description, my guess is the lens could have been opened up and serviced and when re-assembled, wasn't collimated and adjusted for infinity focus.
07-09-2007, 04:58 PM   #3
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Join Date: Sep 2006
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The package wasn't damaged when you got it was it?

Why not write a Private Message to the member you bought this lens from JahJahwarrior, there might just be some little secret that you haven't discovered yet.

I'm of course hoping that he used it and found a way to work around this flaw.

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