FA 31 Owners - is there any play in the front of your lens?

LeRolls · 11-02-2015, 10:55 PM - **1 Like**

This was a concern for me as well when I first purchased my 31 as it has a little give. Thought about returning it to B&H during the first month but decided against it. I've never had a problem and I consider it a great lens.

Sandy Hancock · 11-03-2015, 02:14 AM - **1 Like**

Originally posted by LeRolls

This was a concern for me as well when I first purchased my 31 as it has a little give. Thought about returning it to B&H during the first month but decided against it. I've never had a problem and I consider it a great lens.

Yep. I have had mine for three years and I would only consider trading it if a mint MIJ silver copy came up to match my other Two Amigos. For now, it does everything I could possibly want except look purrrrty.

johnmflores · 11-03-2015, 07:19 AM

There is the slightest movement in mine if you grip the front securely and try to move it. I'm guessing that what you are feeling is the slight gap between the lens helicoids. You can feel it with other lenses too, but it's easier to reproduce with the longer FA31 vs. the DA21 which I happen to have on my desk.

Squirrel · 11-03-2015, 07:47 AM

Mine is AIV and has a slight wobble, but no effect on image quality. There was a very similar thread about 6 months ago, I would guess, and the responses were the same. Common problem unfortunately.

**UncleVanya** · 11-03-2015, 08:29 AM

Originally posted by Squirrel

Mine is AIV and has a slight wobble, but no effect on image quality. There was a very similar thread about 6 months ago, I would guess, and the responses were the same. Common problem unfortunately.

Thanks. I think my mind is more at ease with all of the superb photographers that use this lens telling me that theirs is similar. Thanks to all.

gda13 · 11-03-2015, 09:47 AM

Just the minutest amount of play with my MIJ copy, but quite a bit of force must be applied before that happens.

drypenn · 11-03-2015, 10:14 AM

Mine is AIV, argentine. No wobble or play. As tight as it can be. But yet, for manual focusing the 77 seems a lot easier.

**Just1MoreDave** · 11-04-2015, 12:39 PM

I remember (but can't find) a description of the FA31's complicated construction, which makes the wobble more likely. The other FA Limiteds have a more conventional build. One forum member was fairly critical of this wobble and construction. I can't find him either so maybe he moved on to something perfect.

**UncleVanya** · 11-04-2015, 02:00 PM

Originally posted by Just1MoreDave

I remember (but can't find) a description of the FA31's complicated construction, which makes the wobble more likely. The other FA Limiteds have a more conventional build. One forum member was fairly critical of this wobble and construction. I can't find him either so maybe he moved on to something perfect.

Now I'm intrigued - I would love to know more. Anyone?

**filoxophy** · 11-04-2015, 02:45 PM

Originally posted by UncleVanya

Now I'm intrigued - I would love to know more. Anyone?

Probably only the engineers know the true story, if there is one. I'm very happy with my 31. It's not perfect, but it's damn good for a film era lens.

**Just1MoreDave** · 11-04-2015, 04:24 PM

Originally posted by UncleVanya

Now I'm intrigued - I would love to know more. Anyone?

This diagram isn't easy to understand but does point out the parts he was complaining about.

http://www.pentax-manuals.com/manuals/service/fa31.pdf

**Digitalis** · 11-04-2015, 05:50 PM

Originally posted by Just1MoreDave

I remember (but can't find) a description of the FA31's complicated construction, which makes the wobble more likely. The other FA Limiteds have a more conventional build.

you're suggesting that there are FA31s that have different construction from the others? and that there is probably no way of knowing short of stripping the lens down to find out which is which?

**UncleVanya** · 11-04-2015, 06:38 PM

Originally posted by Digitalis

you're suggesting that there are FA31s that have different construction from the others? and that there is probably no way of knowing short of stripping the lens down to find out which is which?

I read this as tolerance differences in the 31's could result from n wobble and other FA limiters 77 and 43 have different designs that don't have this complex of a construction.

virusn3t · 11-04-2015, 06:39 PM

My 31 have a small woble on the lens group if i shake gently the lens a small "tick" sond can be heard, and if i put my finger on the lens where the mount is i can move the lens group (maybe 1mm or less, but you can feel it move) but regard at cosntruccion of the exterior is very solid, my copy is AIV

Aberrator · 11-05-2015, 12:52 PM

Originally posted by virusn3t

and if i put my finger on the lens

Just how many FA31 lenses now have fingerprints all over them or were destroyed completely by overzealous readers trying to reproduce this mystical "wobble"?

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11-02-2015, 10:55 PM - 1 Like	#16
LeRolls Pentaxian Join Date: Oct 2012 Location: PSL, FL Posts: 4,504	This was a concern for me as well when I first purchased my 31 as it has a little give. Thought about returning it to B&H during the first month but decided against it. I've never had a problem and I consider it a great lens.

11-03-2015, 02:14 AM - 1 Like	#17
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275	Originally posted by LeRolls This was a concern for me as well when I first purchased my 31 as it has a little give. Thought about returning it to B&H during the first month but decided against it. I've never had a problem and I consider it a great lens. Yep. I have had mine for three years and I would only consider trading it if a mint MIJ silver copy came up to match my other Two Amigos. For now, it does everything I could possibly want except look purrrrty.

11-03-2015, 07:19 AM	#18
johnmflores Veteran Member Join Date: Apr 2009 Location: Somerville, NJ Photos: Gallery \| Albums Posts: 5,361	There is the slightest movement in mine if you grip the front securely and try to move it. I'm guessing that what you are feeling is the slight gap between the lens helicoids. You can feel it with other lenses too, but it's easier to reproduce with the longer FA31 vs. the DA21 which I happen to have on my desk.

11-03-2015, 07:47 AM	#19
Squirrel Junior Member Join Date: Apr 2012 Location: Seacoast NH Posts: 41	Mine is AIV and has a slight wobble, but no effect on image quality. There was a very similar thread about 6 months ago, I would guess, and the responses were the same. Common problem unfortunately.

11-03-2015, 08:29 AM	#20
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,446 Original Poster	Originally posted by Squirrel Mine is AIV and has a slight wobble, but no effect on image quality. There was a very similar thread about 6 months ago, I would guess, and the responses were the same. Common problem unfortunately. Thanks. I think my mind is more at ease with all of the superb photographers that use this lens telling me that theirs is similar. Thanks to all.

11-03-2015, 09:47 AM	#21
gda13 Pentaxian Join Date: Aug 2010 Location: Florida Photos: Gallery \| Albums Posts: 1,108	Just the minutest amount of play with my MIJ copy, but quite a bit of force must be applied before that happens.

11-03-2015, 10:14 AM	#22
drypenn Veteran Member Join Date: Nov 2012 Photos: Albums Posts: 963	Mine is AIV, argentine. No wobble or play. As tight as it can be. But yet, for manual focusing the 77 seems a lot easier.

11-04-2015, 12:39 PM	#23
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	I remember (but can't find) a description of the FA31's complicated construction, which makes the wobble more likely. The other FA Limiteds have a more conventional build. One forum member was fairly critical of this wobble and construction. I can't find him either so maybe he moved on to something perfect.

11-04-2015, 02:00 PM	#24
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,446 Original Poster	Originally posted by Just1MoreDave I remember (but can't find) a description of the FA31's complicated construction, which makes the wobble more likely. The other FA Limiteds have a more conventional build. One forum member was fairly critical of this wobble and construction. I can't find him either so maybe he moved on to something perfect. Now I'm intrigued - I would love to know more. Anyone?

11-04-2015, 02:45 PM	#25
filoxophy Site Supporter Join Date: Jul 2012 Location: Albuquerque Posts: 1,133	Originally posted by UncleVanya Now I'm intrigued - I would love to know more. Anyone? Probably only the engineers know the true story, if there is one. I'm very happy with my 31. It's not perfect, but it's damn good for a film era lens.

11-04-2015, 04:24 PM	#26
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	Originally posted by UncleVanya Now I'm intrigued - I would love to know more. Anyone? This diagram isn't easy to understand but does point out the parts he was complaining about. http://www.pentax-manuals.com/manuals/service/fa31.pdf

11-04-2015, 05:50 PM	#27
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by Just1MoreDave I remember (but can't find) a description of the FA31's complicated construction, which makes the wobble more likely. The other FA Limiteds have a more conventional build. you're suggesting that there are FA31s that have different construction from the others? and that there is probably no way of knowing short of stripping the lens down to find out which is which?

11-04-2015, 06:38 PM	#28
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,446 Original Poster	Originally posted by Digitalis you're suggesting that there are FA31s that have different construction from the others? and that there is probably no way of knowing short of stripping the lens down to find out which is which? I read this as tolerance differences in the 31's could result from n wobble and other FA limiters 77 and 43 have different designs that don't have this complex of a construction.

11-04-2015, 06:39 PM	#29
virusn3t Veteran Member Join Date: Jul 2014 Posts: 676	My 31 have a small woble on the lens group if i shake gently the lens a small "tick" sond can be heard, and if i put my finger on the lens where the mount is i can move the lens group (maybe 1mm or less, but you can feel it move) but regard at cosntruccion of the exterior is very solid, my copy is AIV

11-05-2015, 12:52 PM	#30
Aberrator Forum Member Join Date: Aug 2014 Location: Kaunas Photos: Gallery Posts: 97	Originally posted by virusn3t and if i put my finger on the lens Just how many FA31 lenses now have fingerprints all over them or were destroyed completely by overzealous readers trying to reproduce this mystical "wobble"?