How much play is normal for a focus ring?

FH_le · 01-11-2011, 11:55 AM

I just got a Pentax Smc-A 50mm /f1.4 which at first sight does a very good job taking pictures. The focus ring, however, appears a little loose to me. The front element can be moved slightly forth and back (~0.5mm). I don't have so much experience with old manual focus lenses but my old Minolta lenses never showed such play. So do I have to worry? How much play is normal for a manual focus lens ?
(I could sent the lens back, but optically it is fine, so I don't now if I am just too cautious.)

Manel Brand · 01-11-2011, 12:46 PM

Check the small screw on the lens barrel (you are able to see it when the barrel is full extended). Use an appropriate screw driver to tight it up if it has become loose. It may cause the problem you are reporting.

**Ash** · 01-11-2011, 01:35 PM

Most MF lenses shouldn't have any play in them.
So tighten those screws referred to above and see how you go.

nanhi · 01-12-2011, 09:36 AM

Hello friend, the front lens element should not move at all - to and fro. It means the front lens ring is loose and not sitting snugly against the lens. Some lenses have rings with diametrically opposite slots and these can be tightened with a pair of calipers or lens wrench. Others have a broad ring driven by friction. You can use a truck tube and a piece of hard plastic large diameter water pipe to tighten such a ring. Or if you are not a DIY type, take it to a camera repair guy.
You have a truly great lens. Happy shooting.

Manel Brand · 01-17-2011, 12:58 PM

Originally posted by FH_le

but my old Minolta lenses never showed such play

Howdy, how's playing your Pentax 50mm? Don't forget to come back and tell us... I'm sustaining my breath.. and a simple thanks to us may help your future inquires (LOL). Cheers.

FH_le · 01-17-2011, 01:11 PM

Originally posted by Manel Brand

Howdy, how's playing your Pentax 50mm? Don't forget to come back and tell us... I'm sustaining my breath.. and a simple thanks to us may help your future inquires (LOL). Cheers.

Thanks (and sorry for not posting earlier)!
Fixing the lens was not possible with the easily accesible screws. So today I finally sent the lens back. So no detailed reports on the 50mm so far...

**germar** · 01-17-2011, 01:31 PM

I'm again late to the party with a comment, but for future reference:

I have an SMC A 28mm 2.8 that has a detectable wiggle in the focus ring. You can feel it, and you can see it if you are looking at the lens. Honestly, I was going to return the lens for refund until I took some test shots and really looked at them ... damned sharpest lens of this type I've ever owned.

I decided that if the lens came apart in my hands someday, so be it ... and I've used the lens many times since ... getting wonderful images with it.

I would agree that there shouldn't be a wiggle in the lens, but I think you missed the point .... how did the lens actually shoot? Unless you simply can't sleep at night because of the wiggle, I would make a call like this on the quality of images you got. If it's a killer copy, what's a little wiggle?

Just my very late .02. Good luck with your search for a better copy.

irakliszs · 01-15-2023, 09:56 PM - **1 Like**

Hello pentaxians!
I am a long time lurker of these excellent forums, now decided to post a question because I cannot seem to be able to find an answer.
It is an old thread but it is the same lens and the same issue so I figured I should not open a new one.
Similar to the OP's case, I just received an SMC A 50mm f1.4 and noticed somewhat loose focusing ring feeling (not as tight/dumpened as my SMC M 50mm f1.7) and also a little play.
I recorded a video to show the amount of play:

lens play - YouTube

I cannot explain much the tightness of the focusing ring, since I have only experience with the M f1.7 version which is really tight and it is hard to put in words (it is subjective after all). But is this amount of play normal? Is this something I should be worried about?

Appreciate any input!
Thank you very much!

**Just1MoreDave** · 01-16-2023, 05:11 PM

This lens is built a little differently than the K or M versions. I am going on a really old memory of how it goes together, so I could be off. I believe this is how it goes:
Turn the focus ring to the minimum distance
Look on the side of the lens barrel, the thing you're holding in the video
There should be a very small slotted screw, painted black, flush with the barrel, close to the edge of the focus ring.
A screwdriver from an eyeglass repair kit should fit this screw. Loosen it a few turns. If it falls out, it's a little tricky to reinstall.
You can then unscrew the lens barrel and expose other screws.

Unfortunately I can't remember anything else about this lens, but I don't think it should be loose like that.

irakliszs · 01-16-2023, 08:58 PM

Thank you Dave!
So it seems I will have to repair it.
Is it just a matter of tightening screws, or maybe it has to do with normal wear?
To tell the truth, I kind of hesitate to try to open it, I am afraid that I might mess it up.

Jonathan Mac · 01-17-2023, 06:21 AM

Obviously each lens is different in exactly how well it's made and each lens copy has it's own history of use and abuse, but as a rule the A series is where Pentax build quality started to go downhill. It's most noticeable in the cheaper 50mm lenses (f/2 and f/1.7) and their gritty aperture rings but even on others there's more plastic used instead of metal. Unless there's a specific reason to get an A lens (faster, better optical formula, or you need the auto-aperture) then the older K and M series are much better built and give a better vintage lens user experience.

irakliszs · 01-18-2023, 09:52 PM

Thanks for the input everyone!
Well, I got this because of the A setting.
Maybe I worry too much for this?
Should I try to fix it or should I just live with it?

**robgski** · 01-19-2023, 03:41 AM

Originally posted by irakliszs

Thanks for the input everyone!
Well, I got this because of the A setting.
Maybe I worry too much for this?
Should I try to fix it or should I just live with it?

Used gear has been used, and If you are satisfied with the images the lens produces, Live with it, and enjoy it.

01-11-2011, 11:55 AM	#1
FH_le Forum Member Join Date: Jan 2011 Location: Leipzig Photos: Gallery \| Albums Posts: 64	How much play is normal for a focus ring? I just got a Pentax Smc-A 50mm /f1.4 which at first sight does a very good job taking pictures. The focus ring, however, appears a little loose to me. The front element can be moved slightly forth and back (~0.5mm). I don't have so much experience with old manual focus lenses but my old Minolta lenses never showed such play. So do I have to worry? How much play is normal for a manual focus lens ? (I could sent the lens back, but optically it is fine, so I don't now if I am just too cautious.)

01-17-2011, 01:11 PM	#6
FH_le Forum Member Join Date: Jan 2011 Location: Leipzig Photos: Gallery \| Albums Posts: 64 Original Poster	Originally posted by Manel Brand Howdy, how's playing your Pentax 50mm? Don't forget to come back and tell us... I'm sustaining my breath.. and a simple thanks to us may help your future inquires (LOL). Cheers. Thanks (and sorry for not posting earlier)! Fixing the lens was not possible with the easily accesible screws. So today I finally sent the lens back. So no detailed reports on the 50mm so far... Last edited by FH_le; 01-17-2011 at 01:17 PM.

01-15-2023, 09:56 PM - 1 Like	#8
irakliszs New Member Join Date: Aug 2020 Posts: 3	SMC A 50mm f1.4 barrel play Hello pentaxians! I am a long time lurker of these excellent forums, now decided to post a question because I cannot seem to be able to find an answer. It is an old thread but it is the same lens and the same issue so I figured I should not open a new one. Similar to the OP's case, I just received an SMC A 50mm f1.4 and noticed somewhat loose focusing ring feeling (not as tight/dumpened as my SMC M 50mm f1.7) and also a little play. I recorded a video to show the amount of play: lens play - YouTube I cannot explain much the tightness of the focusing ring, since I have only experience with the M f1.7 version which is really tight and it is hard to put in words (it is subjective after all). But is this amount of play normal? Is this something I should be worried about? Appreciate any input! Thank you very much!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
DA L 55-300mm zoom ring play, gap	bwDraco	Pentax SLR Lens Discussion	5	12-27-2010 06:46 AM
HELP NEEDED: DA*50-135mm play in zoom ring	RogerD_AZ	Pentax SLR Lens Discussion	8	05-25-2010 09:20 PM
Focus Ring?	NecroticSoldier	Troubleshooting and Beginner Help	6	04-26-2010 12:50 PM
Tamron Focus Ring	Mike.P®	Pentax SLR Lens Discussion	0	06-01-2008 04:04 AM
Voigtlander 180mm stiff focus normal?	jsherman999	Pentax SLR Lens Discussion	4	03-01-2008 10:14 AM

01-11-2011, 12:46 PM	#2
Manel Brand Veteran Member Join Date: Sep 2008 Location: Porto Photos: Gallery \| Albums Posts: 853	Check the small screw on the lens barrel (you are able to see it when the barrel is full extended). Use an appropriate screw driver to tight it up if it has become loose. It may cause the problem you are reporting.

01-11-2011, 01:35 PM	#3
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Most MF lenses shouldn't have any play in them. So tighten those screws referred to above and see how you go.

01-12-2011, 09:36 AM	#4
nanhi Veteran Member Join Date: May 2009 Location: Bangalore, India Photos: Gallery \| Albums Posts: 469	Hello friend, the front lens element should not move at all - to and fro. It means the front lens ring is loose and not sitting snugly against the lens. Some lenses have rings with diametrically opposite slots and these can be tightened with a pair of calipers or lens wrench. Others have a broad ring driven by friction. You can use a truck tube and a piece of hard plastic large diameter water pipe to tighten such a ring. Or if you are not a DIY type, take it to a camera repair guy. You have a truly great lens. Happy shooting.

01-17-2011, 12:58 PM	#5
Manel Brand Veteran Member Join Date: Sep 2008 Location: Porto Photos: Gallery \| Albums Posts: 853	Originally posted by FH_le but my old Minolta lenses never showed such play Howdy, how's playing your Pentax 50mm? Don't forget to come back and tell us... I'm sustaining my breath.. and a simple thanks to us may help your future inquires (LOL). Cheers.

01-17-2011, 01:31 PM	#7
germar Site Supporter Join Date: Apr 2007 Location: North Palm Beach, Florida Photos: Gallery Posts: 728	I'm again late to the party with a comment, but for future reference: I have an SMC A 28mm 2.8 that has a detectable wiggle in the focus ring. You can feel it, and you can see it if you are looking at the lens. Honestly, I was going to return the lens for refund until I took some test shots and really looked at them ... damned sharpest lens of this type I've ever owned. I decided that if the lens came apart in my hands someday, so be it ... and I've used the lens many times since ... getting wonderful images with it. I would agree that there shouldn't be a wiggle in the lens, but I think you missed the point .... how did the lens actually shoot? Unless you simply can't sleep at night because of the wiggle, I would make a call like this on the quality of images you got. If it's a killer copy, what's a little wiggle? Just my very late .02. Good luck with your search for a better copy.

01-16-2023, 05:11 PM	#9
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	This lens is built a little differently than the K or M versions. I am going on a really old memory of how it goes together, so I could be off. I believe this is how it goes: Turn the focus ring to the minimum distance Look on the side of the lens barrel, the thing you're holding in the video There should be a very small slotted screw, painted black, flush with the barrel, close to the edge of the focus ring. A screwdriver from an eyeglass repair kit should fit this screw. Loosen it a few turns. If it falls out, it's a little tricky to reinstall. You can then unscrew the lens barrel and expose other screws. Unfortunately I can't remember anything else about this lens, but I don't think it should be loose like that.

01-16-2023, 08:58 PM	#10
irakliszs New Member Join Date: Aug 2020 Posts: 3	Thank you Dave! So it seems I will have to repair it. Is it just a matter of tightening screws, or maybe it has to do with normal wear? To tell the truth, I kind of hesitate to try to open it, I am afraid that I might mess it up.

01-17-2023, 06:21 AM	#11
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,911	Obviously each lens is different in exactly how well it's made and each lens copy has it's own history of use and abuse, but as a rule the A series is where Pentax build quality started to go downhill. It's most noticeable in the cheaper 50mm lenses (f/2 and f/1.7) and their gritty aperture rings but even on others there's more plastic used instead of metal. Unless there's a specific reason to get an A lens (faster, better optical formula, or you need the auto-aperture) then the older K and M series are much better built and give a better vintage lens user experience.

01-18-2023, 09:52 PM	#12
irakliszs New Member Join Date: Aug 2020 Posts: 3	Thanks for the input everyone! Well, I got this because of the A setting. Maybe I worry too much for this? Should I try to fix it or should I just live with it?

01-19-2023, 03:41 AM	#13
robgski Loyal Site Supporter Join Date: Nov 2012 Location: Shenandoah Valley, Virginia Photos: Gallery \| Albums Posts: 8,817	Originally posted by irakliszs Thanks for the input everyone! Well, I got this because of the A setting. Maybe I worry too much for this? Should I try to fix it or should I just live with it? Used gear has been used, and If you are satisfied with the images the lens produces, Live with it, and enjoy it.