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06-09-2012, 02:13 PM   #1
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Location: Winnipeg, Canada
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Question about 645 300 f4 EDIF and I'm new here.

I'm looking at a 645 A* 300mm f4 EDIF, and I notice it focuses past infinity. Infinity is right on the mark, the lens is in excellent condition as well. No slop, no dings or dents, just a couple of fine scratches on the barrel.

Is this going past the infinity mark normal on the manual focus model?

Other than that, I do my own film processing inc C41 and print it in the darkroom as well.

06-09-2012, 04:28 PM   #2
Pål Jensen's Avatar

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It is normal on all longer telephoto lenses. It is for compensating for thermal expansion/contraction.

Last edited by Pål Jensen; 06-09-2012 at 04:42 PM.
06-09-2012, 04:53 PM   #3
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Original Poster
I know it's a feature of the newer AF lenses and the manual focus 400mm EDIF, I just haven't found anything definitive regarding the 300. It sure is a nice lens from the one test roll I've shot. Plus it is very insistent about enforcing proper hand holding technique.
06-10-2012, 09:52 AM   #4
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Location: Beach Haven, NJ
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I also have the 300mm A lens, along with 10 other MF and AF 645 lenses. One lens I bought as "New Old Stock" came with the official 645 lens instruction book, which covers all the MF lens offered at the time. It states that (actual quote): "powerful telephotos SMC A645 300mm f4 ED (IF), and SMC A645 600mm f5.6 ED (IF)" are specially designed to rotate slightly past infinity. The reason given is to allow for temperature conditions such hot and cold weather.
BTW it is a lovely lens, and so is the matched 1.4X converter which I found as new old stock. I use them on a 645D.
Good luck
Dave in NJ

06-10-2012, 01:21 PM   #5
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Thanks Dave, and please don't twist my arm any more to buy the TC as well, I am doing that very well already.

I just measured mine, it goes a hair over 5mm past infinity and 6mm past the 3m mark.Well as close as I can measure with a $2 plastic ruler.

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