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09-04-2011, 12:32 PM   #16
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It is sideways movement. I did buy a pinch cap from B&H. It just seems wisest to keep the lens as long as I can since there is no optical problem with it. If it gets worse before the year is up, I will warranty it.

10-12-2011, 02:16 PM   #17
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Lateral Lens Barrel Movement.

I bought a Silver AIV 31mm last week and it had horrendous lateral movement of the inner lens barrel. It was also soft wide-open so I replaced it and actually met the sales rep' in the store for the swap. The replacement was a black AIV unit which still had some movement (still more than I'd like) but much less than the silver one had. Without having touched any other 31mm LTD lens I cannot say for sure what the 'norm' is although one person here has stated that their lens has absolutely no lateral movement in the barrel. I have a MIJ 77LTD that I bought used a few months ago and that lens has none of these issues. Both the sales rep' and the store salesman told me that there's nothing wrong with the degree of movement in the second lens but that the 1st was definitely not right. It seems to me that any lateral 'tilt' of the lens is going to translate in the edges of the field being out of focus in critical shots so I tend to disagree with them on that point. If I return this lens it will be for a refund and not another swap out as there's no more stock of this lens in Australia.

Maybe we should start a poll to determine just how common these issues are?
10-12-2011, 06:56 PM   #18
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My black AIV has no issues at all. Very sharp lens. Less than a year old.
Joe
10-12-2011, 07:13 PM   #19
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Mine is still very sharp even at f/2.


Last edited by miltona580; 10-13-2011 at 07:23 AM.
10-13-2011, 03:57 PM - 1 Like   #20
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I have a black AIV FA31 that has absolutely no wobble or movement of the barrel or hood at all, although it does make a faint whiring noise during focusing (off camera). My copy is very sharp right from wide open.
10-13-2011, 04:29 PM   #21
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Thanks for the replies.

Would any of you have accepted a 31mm LTD with a slight wobble or 'play' in the barrel? The salesman and the rep I spoke to kept bringing up Leica saying that even their most expensive lenses had some 'slop'. I can't imagine any tilting of the optics being good for the focal point of the lens.

It'd be interesting to see some pic's from the lenses you guys mentioned (the ones without issue) wide open and with bright lights or specular highlights in the field of view as I'm still not convinced my copy of the lens is how it should be for the money. The lens I have has no longitudinal movement apart from focal movement (and seems very sharp as well) but I have no idea as to the degree of any shift in the focal point position on the sensor due to the lateral movement. I think I'll give a local lens tech a look at the lens for an opinion.
10-13-2011, 05:19 PM   #22
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I guess the majority of FA31 wobble to some degree based on my experience, my current sample included, slightly but definitely has impact on optical alignment. I managed to realign it almost perfectly for landscape orientation, but one of the corners will suffer in portrait orientation depends how it is rotated. It's not that bad really but the difference is there when inspected carefully wide open. Then again, I suppose the majority of production lenses aren't perfect of any brand. To give you an idea how sharp this lens can be wide open, I have taken a shot on 40D and converted by LR with default setting, no extra sharpening. Be aware that the lack of sharpness in some areas may be due to shallow DOF. The only reason it wasn't taken with my K-m is due to Pentax AF deficiency near infinity (I am certain some would call me a troll because of this ).

FA31 wide open 2 photo - Alan Chan photos at pbase.com
10-13-2011, 06:08 PM   #23
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Thanks for the links. It's a pity they are not available for download as it'd be nice to load them up with lightroom to do a side-by-side compare to my own stuff.

Cheers

10-13-2011, 06:21 PM   #24
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See if this works. Email me if you want the original raw file to play with.

10-13-2011, 06:29 PM   #25
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Thanks Alan.. I grabbed that fine and will take a closer look.

Cheers.
01-17-2013, 03:32 AM   #26
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QuoteOriginally posted by bossa Quote
I bought a Silver AIV 31mm last week and it had horrendous lateral movement of the inner lens barrel. It was also soft wide-open so I replaced it and actually met the sales rep' in the store for the swap. The replacement was a black AIV unit which still had some movement (still more than I'd like) but much less than the silver one had. Without having touched any other 31mm LTD lens I cannot say for sure what the 'norm' is although one person here has stated that their lens has absolutely no lateral movement in the barrel. I have a MIJ 77LTD that I bought used a few months ago and that lens has none of these issues. Both the sales rep' and the store salesman told me that there's nothing wrong with the degree of movement in the second lens but that the 1st was definitely not right. It seems to me that any lateral 'tilt' of the lens is going to translate in the edges of the field being out of focus in critical shots so I tend to disagree with them on that point. If I return this lens it will be for a refund and not another swap out as there's no more stock of this lens in Australia.

Maybe we should start a poll to determine just how common these issues are?
Our FA31, bought from B&H, was very, very soft, but like 'Bossa' I've since then given up and moved on to Nikon-
01-17-2013, 04:05 AM   #27
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QuoteOriginally posted by bossa Quote
Would any of you have accepted a 31mm LTD with a slight wobble or 'play' in the barrel? The salesman and the rep I spoke to kept bringing up Leica saying that even their most expensive lenses had some 'slop'. I can't imagine any tilting of the optics being good for the focal point of the lens.
Well if we had a more recent pentax meet for us Adelaide pentaxians we could have compared notes on the FA31mm f/1.8 ASPH Limited - my copy is an exceptionally good MIJ copy, no wobbles of any sort and optically about as good as it gets.

01-21-2013, 03:26 AM   #28
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I know this is an old thread that Tord has started again.

Just to mention i have a AIV copy from bhphoto (close to 2 years). There is no wobble and optically one of the best lenses i have.
03-28-2013, 02:28 PM   #29
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I just bought another FA31 from a Pentax Australia website that was running a special over Easter.. I guess I'll find out soon enough whether it will have any wobbles.
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