Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-04-2011, 08:21 PM   #1
Pentaxian




Join Date: Dec 2008
Location: launceston
Posts: 1,075
50/f1.2 focus noise on LX but not GH2..?

Hi everyone,

I recently tried out my new K50/f1.2 on my LX for the first time and noticed an odd noise when focussing from closest-infinity (no noise the other way). It's a very faint 'ticking' - kind of like someone flicking paper...

The odd thing is that the K50 focusses absolutely silently when adapted on my Panasonic GH2. Likewise, all my other SMC lenses are silent on the LX (K24, M50, K135).

Any ideas?

Cheers, Nick

10-04-2011, 08:25 PM   #2
Veteran Member
frank's Avatar

Join Date: Nov 2006
Location: Singapore
Photos: Gallery
Posts: 3,202
That sounds odd. Cameras shouldn't affect focusing at all w/ these manual lenses. You might try it again on your GH2, or better yet, just take it off camera and turn the focusing ring left and right to see if it makes any noise.
10-04-2011, 08:39 PM   #3
Pentaxian




Join Date: Dec 2008
Location: launceston
Posts: 1,075
Original Poster
QuoteOriginally posted by frank Quote
That sounds odd. Cameras shouldn't affect focusing at all w/ these manual lenses. You might try it again on your GH2, or better yet, just take it off camera and turn the focusing ring left and right to see if it makes any noise.

I've tried it several times on the LX, several times on the GH2, several times just mounted to the adapter, and several times with the lens by itself (even with and without the rear lens-cap)...

It only makes the noise on the LX, and it always makes the noise on the LX (ie: it's not an intermittent problem...)
10-04-2011, 10:36 PM   #4
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by frank Quote
That sounds odd. Cameras shouldn't affect focusing at all w/ these manual lenses
I agree, unless there is something catastrophically wrong with your lens it should be absolutely silent on both cameras.

10-04-2011, 11:44 PM   #5
Pentaxian




Join Date: Dec 2008
Location: launceston
Posts: 1,075
Original Poster
QuoteOriginally posted by Digitalis Quote
I agree, unless there is something catastrophically wrong with your lens it should be absolutely silent on both cameras.
Should be, but isn't...
10-05-2011, 12:17 AM   #6
Pentaxian
hoanpham's Avatar

Join Date: Nov 2009
Location: Strand
Photos: Gallery | Albums
Posts: 1,360
Does it make sound when you disconnect the lens from the body, and turn/focus the lens slowly?
Seems like a defective to me.
10-05-2011, 02:33 AM   #7
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
sounds more to me like there is something up with your LX not your lens. do you have another lens to try on your LX, to see if you can replicate the sound?
10-05-2011, 03:21 AM   #8
Pentaxian




Join Date: Dec 2008
Location: launceston
Posts: 1,075
Original Poster
QuoteOriginally posted by séamuis Quote
sounds more to me like there is something up with your LX not your lens. do you have another lens to try on your LX, to see if you can replicate the sound?
As I mentioned in the OP, I've tried my K24/f2.8, M50/f1.4 and K135/f2.5 on the LX and none of them make a sound.

QuoteOriginally posted by hoanpham Quote
Does it make sound when you disconnect the lens from the body, and turn/focus the lens slowly?
Seems like a defective to me.
Also as mentioned in the OP, the K50 lens makes no sound when disconnected from the body.

10-05-2011, 05:03 AM   #9
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
QuoteOriginally posted by nickthetasmaniac Quote
As I mentioned in the OP, I've tried my K24/f2.8, M50/f1.4 and K135/f2.5 on the LX and none of them make a sound.



Also as mentioned in the OP, the K50 lens makes no sound when disconnected from the body.
I have to recant my first comment as I was, for some reason reading ‘focus’ and somehow thinking ‘aperture’, in which I was blaming the LX for a possible problem with the coupling. but if we are talking focusing here, I can’t see how any camera could be to blame. it has to be the lens, so the fact that it only happens when mounted to the LX seems strange to me. there is no linkage whatsoever between a manual focus pentax lens and a manual focus pentax body, not even the LX. (in regards to the focusing mechanism) the focusing mechanism is completely internal. the only thing that could be a possibility is that when near or at infinity, the rear element of the lens (which at that point would be at it farthest extension from the back of the lens and into the mirror box) could be possibly contacting something? I just can see how it could only be replicated on the LX, when in theory it shouldn’t matter if its even mounted to anything at all concerning the focusing. do you have another K mount camera to test the 50 on? does this only happen when wide open? have you tested it with all aperture settings?

id like to help, but I’m at a bit of a loss. I would ask you to maybe shoot some video of the problem if thats a possibility, but I understand that wouldn’t be easy to do and accurately capture the sound.

Last edited by séamuis; 10-05-2011 at 05:10 AM.
10-05-2011, 05:06 AM   #10
Site Supporter
ismaelg's Avatar

Join Date: Apr 2009
Location: Puerto Rico
Photos: Gallery
Posts: 951
Does it happen at all apertures? I once had a problem with an older film body (Yashica) and after driving me nuts for a while it was a slightly bent aperture lever. This sounds like something different, but just to rule that out.

Thanks,
10-05-2011, 01:49 PM   #11
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,814
QuoteOriginally posted by séamuis Quote
... the only thing that could be a possibility is that when near or at infinity, the rear element of the lens (which at that point would be at it farthest extension from the back of the lens and into the mirror box) could be possibly contacting something?
My theory too. The K135 rear element won't extend deep into the mount; it looks like this:



I think the K50/1.2 is the most likely to have a large diameter, deeper extension into the camera.

I'm relieved it's not the 135 that's the problem!
10-05-2011, 02:56 PM   #12
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by séamuis Quote
the rear element of the lens (which at that point would be at it farthest extension from the back of the lens and into the mirror box) could be possibly contacting something?
If that was the case, the lens would be focusing past infinity by a considerable amount.
10-05-2011, 03:03 PM   #13
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
QuoteOriginally posted by Digitalis Quote
If that was the case, the lens would be focusing past infinity by a considerable amount.
ah, well I’ve never used a 1.2 so I didn’t know if it were somehow different in this respect to other lenses, it was just a possible guess on my part. thanks for the correction. I still can’t figure out how the focusing could only be affected by one camera body, when in theory it shouldn’t matter if its even mounted to a camera at all. the only thing I can really think of is that its somehow connected to the aperture mechanism inside the lens and thus appears only when mounted on a camera that couples with the Kmount aperture mechanism. unless mFT Kmount adapters also have mechanical couplers? I think the next ‘rule out’ really has to be testing the lens on another kmount body.
10-05-2011, 03:28 PM   #14
Pentaxian




Join Date: Dec 2008
Location: launceston
Posts: 1,075
Original Poster
QuoteOriginally posted by Just1MoreDave Quote
I think the K50/1.2 is the most likely to have a large diameter, deeper extension into the camera.

I'm relieved it's not the 135 that's the problem!
The rear element of the K50/f1.2 is very big - it literally fills all of the available space within the mount - but it doesn't extend past the rear-most part of the mount, so I don't think that should matter. The mirror-stops in the LX were replaced about a year ago and I'm wondering if that's making something stick out more than it should

Haha the 135 has been fantastic - I'm waiting to get back a roll of Provia Thanks again Dave!


QuoteOriginally posted by séamuis Quote
unless mFT Kmount adapters also have mechanical couplers? I think the next ‘rule out’ really has to be testing the lens on another kmount body.
PK-mFT adapters are literally just a metal tube. The only moving part they have is the mount-lock...
10-05-2011, 06:40 PM   #15
Veteran Member
Andi Lo's Avatar

Join Date: Jul 2008
Location: Halifax, Nova Scotia
Posts: 2,925
Not sure if it's related but my sigma 10-20mm makes small grinding noise (and feel) when zoomed from 12-14mm only when mounted. I think the focusing ring of your lens is somewhat connected to the aperture acutation.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, lx, noise, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Focus Ring on DA 35 macro makes a clicking noise; manual focus ... this normal? eadrian75 Pentax SLR Lens Discussion 2 04-12-2011 12:51 AM
Whirling noise during the live view focus jannking Pentax K-r 18 02-26-2011 04:56 PM
Problem with new K-5 with focus/noise candgpics Pentax K-5 12 12-07-2010 03:09 PM
Focus motor noise. Is it a concern? Sitting Bull Pentax DSLR Discussion 18 01-26-2009 04:16 PM
K10D ISO Noise test, Focus the key joelovotti Pentax DSLR Discussion 15 10-18-2007 02:49 AM



All times are GMT -7. The time now is 02:41 AM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top