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04-04-2012, 07:05 PM   #1
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vivitar 90mm 2.5 bokina + 1:1 adapter infinity focus?

So I know that with the dedicated 1:1 macro adapter the lens can not focus to infinity. What I am wondering is how much focus range you loose? Does it turn it into a hard core macro lens like long extension tubes do to some lenses or can you do medium range work with it? Are you just loosing distant infinity focus or are you loosing your whole focus range except closeups?

04-04-2012, 07:28 PM   #2
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I have neither the lens nor adapter, but here's an educated guess: The adapter is probably about 50mm long. I put 50mm of tubes on a 105mm lens. Far focus is under 35cm. That's probably about your limit.
04-04-2012, 07:28 PM   #3
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I have this lens plus adapter--on full frame it gives infinity to m=0.5 w/o adapter and 0.5 to 1.0 w/ adapter. I haven't used it in several years and only rarely with the adapter--so maybe it is not exactly theses values--but if not it very close--and is (was) advertised that way.
04-04-2012, 07:31 PM   #4
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QuoteOriginally posted by dms Quote
I have this lens plus adapter--on full frame it gives infinity to m=0.5 w/o adapter and 0.5 to 1.0 w/ adapter. I haven't used it in several years and only rarely with the adapter--so maybe it is not exactly theses values--but if not it very close--and is (was) advertised that way.
Thanks for the help. So just to clarify, basically your furthest focus distance with the adapter on is a meter or so?

04-04-2012, 07:34 PM   #5
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QuoteOriginally posted by RioRico Quote
I have neither the lens nor adapter, but here's an educated guess: The adapter is probably about 50mm long. I put 50mm of tubes on a 105mm lens. Far focus is under 35cm. That's probably about your limit.
It is a 3 element adapter so I wasn't sure if the glass just corrected for macro distortion or something or if it changed focal distances in some manner. I wasn't sure if it would behave similar to a similar length macro tube.
04-04-2012, 07:40 PM   #6
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If you are considering it--a bit more info.

The fact that the adapter has a tripod mount is really nice--on the other hand it is very heavy, so backpacking/etc. is a problem. Actually the need to add the adapter, but then it does not work for near distance and infinity makes it less versatile.

I generally carried a regular 2x TC and thus got m=.5 to 1, and infinity focus with it--but lost the len's tripod mount--and likely slightly less IQ. (But I find a regular 2X TC with a good macro lense is superb anyway.)

It is a beautifully made lens and very heavy--but having owned it and Nikon Micro 55mm f3.5 and f/2.8, and Pentax K50mm f4, I personally would not use it for anything outdoors any more--instead I would use a standard macro + 2x TC
04-04-2012, 07:50 PM   #7
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The closest distrance is 15.5 inch w/o and 13.9 inch w/ adapter--but that is from film plane. The lens is about 3.5 inch long and adapter is 1.9 inch--plus add the lens base to film plane (about 1.5 inch)--so you have about 7 inches from front of lens to subject at m=1.
04-04-2012, 07:53 PM   #8
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Thanks a bunch for the info. I have the lens in canon fd mount in nice condition but haven't got around to figuring out how to use it (its been sitting on the shelf for a few months). I could sell it and get a k mount one but k mount ones sell for a lot more than fd mount ones. I could convert it but I'm Leary of tearing up such an expensive lens (if all else fails I might). I was thinking about converting the dedicated adapter but it sounds like that would work for macro only (I don't have one yet but they are a lot cheaper than the lens). I guess an ebay fd-pk adapter would work but the Chinese glass is going to hurt image quality. I'm also working on modifying teleconverters into fd-pk mount adapters with better glass but thats been on hold for a while waiting on tools I can not get locally and haven't got around to ordering.

I'm just kind of fishing for ideas. It's kind of annoying having such a nice piece of glass yet I can not use it. If nothing else I might make a glassless adapter soon so I can use it for macro. Thanks again for the info.

04-04-2012, 08:02 PM   #9
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I am unable to mount another lens on the adapter, and yet I can mount the lens on camera w/o adapter! I never looked very closely at how/why this is. Maybe particular to nikon Ai mount version, or maybe I never properly had/read directions on it's use (I got 2nd hand from B&H)--but that suggest converting the adapter may be tougher than usual (?).
04-04-2012, 08:22 PM   #10
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QuoteOriginally posted by dms Quote
I am unable to mount another lens on the adapter, and yet I can mount the lens on camera w/o adapter! I never looked very closely at how/why this is. Maybe particular to nikon Ai mount version, or maybe I never properly had/read directions on it's use (I got 2nd hand from B&H)--but that suggest converting the adapter may be tougher than usual (?).
I gather you are using a nikon version one on a pentax camera? I did just find one thing that might be promising. I have a doi 1.5x teleconverter in canon fd mount and I just realized, the mount seems to be screwed on (most fd teleconverters have the mount as a single unit with the body so they have to be cut back). That might make mount replacement a lot easier if it is in fact that way.
04-04-2012, 08:36 PM   #11
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No--I am mounting it on Nikon (FM2). Never tried and (from what I heard) unlikely AI mounts on Pentax.
04-04-2012, 09:01 PM   #12
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QuoteOriginally posted by dms Quote
No--I am mounting it on Nikon (FM2). Never tried and (from what I heard) unlikely AI mounts on Pentax.
I bet there is a clearance issue or something like that on the adapter that prevents some lenses from mounting. that is one thing that concerned me converting one is that on some mounts the glass protruded a lot from the back and some don't. These were apparently very much custom designed for the lens and perhaps custom designed for each lens mount.
04-04-2012, 09:10 PM   #13
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Just my luck. I tried to unscrew the mount on the doi teleconverter and damaged 2 of the screw heads (and didn't get them loose). the third made a nice loud crack noise when the screw broke free. Those are some tight screws...
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