View previous topic :: View next topic |
Author |
Message |
guardian
Joined: 18 Mar 2009 Posts: 1746
|
Posted: Thu Jun 28, 2012 1:11 pm Post subject: Rokinon - zoom gone wobbly |
|
|
guardian wrote:
I recently acquired a Rokinon 200mm f4.5 zoom lens with a wobbly front.
The lens was made in Japan, though it might be similar to those of Korean origin. I don't know and, in fact, I know very little about this lens.
My Rokinon lens has nice glass, shows very little use, no abuse, and is close to pristine . . . . . save for the inexplicable wobbliness. When the mount end of the lens is held fixed, the entire front section of the lens, everything in front of the very short mount section, is too free to move about. The front section wobbles freely with perhaps three or four degrees of movement off axis. I've no explanation for it, there being no evidence whatsoever of damage, trauma, etc..
My hope is others might have a copy of this lens and be able to assure me mine should not be like this . . . or perhaps they all are like this. I have considered trying to take the lens apart in effort to learn why it wobbles. I fear, though, I might never be able to reassemble it. |
|
Back to top |
|
|
scsambrook
Joined: 29 Mar 2009 Posts: 2167 Location: Glasgow Scotland
Expire: 2011-11-18
|
Posted: Fri Jun 29, 2012 7:30 am Post subject: |
|
|
scsambrook wrote:
Hi Guardian ! Shame about your wobbly Rokinon . . . and no, it ought not to be like that. No lens should have a wobble. If it's free from any signs of damage, then it's probably because something was either never tightened properly when it was made, or has worked loose over time, as sometimes does inexplicably happen. I'm no mechanic, and have learned that screwdrivers in my hands can effectively be weapons of mass destruction, but if you have a set of the small 'watchmaker's' ones you might try tightening the visible, external, screw heads. It might help . . .
Tearing it apart would be a brave thing to do. But if you bought it cheaply it could be an interesting exercise. Even if you didn't find the cause and/or couldn't reassemble it, you would at least have something new as a subject for macro photos
I doubt it will be a particularly spectacular lens even if put into proper order. From memory Rokinon (or was it Rokunon) was a 'budget price' line.
Anyway, good luck with it - ! _________________ Stephen
Equipment: Pentax DSLR for casual shooting, Lumix G1 and Fuji XE-1 for playing with old lenses, and Leica M8 because I still like the optical rangefinder system. |
|
Back to top |
|
|
guardian
Joined: 18 Mar 2009 Posts: 1746
|
Posted: Fri Jun 29, 2012 5:50 pm Post subject: |
|
|
guardian wrote:
post deleted
Last edited by guardian on Fri Jun 29, 2012 5:54 pm; edited 1 time in total |
|
Back to top |
|
|
guardian
Joined: 18 Mar 2009 Posts: 1746
|
Posted: Fri Jun 29, 2012 5:50 pm Post subject: |
|
|
guardian wrote:
scsambrook wrote: |
Hi Guardian ! Shame about your wobbly Rokinon . . . and no, it ought not to be like that. No lens should have a wobble. If it's free from any signs of damage, then it's probably because something was either never tightened properly when it was made, or has worked loose over time, as sometimes does inexplicably happen. I'm no mechanic, and have learned that screwdrivers in my hands can effectively be weapons of mass destruction, but if you have a set of the small 'watchmaker's' ones you might try tightening the visible, external, screw heads. It might help . . .
Tearing it apart would be a brave thing to do. But if you bought it cheaply it could be an interesting exercise. Even if you didn't find the cause and/or couldn't reassemble it, you would at least have something new as a subject for macro photos
I doubt it will be a particularly spectacular lens even if put into proper order. From memory Rokinon (or was it Rokunon) was a 'budget price' line.
Anyway, good luck with it - ! |
Thank you, Stephen. I appreciate your kind reply to my post. I'm really at a loss here. I have searched the internet on this lens to no avail . . . in an effort to learn if others are having this problem. Matters are confused by fact of this model Rokinon zoom having been made both in Korea and in Japan. The Korean lenses do appear to be second rate. I'm uncertain about the Japanese examples, though they also could easily be of poor quality. Still, a number of internet posts exist from happy and satisfied users of this lens. And nowhere else have I been able to locate anyone reporting my problem with the lens.
Regarding repair:
I am a stupid hamfisted klutz and already have destroyed my quota of lenses for 2012. I managed to wipe out my Zeiss Tessar because I was unaware of correct helicoil reassembly procedure. The lens is now forever locked up. I keep it out in the open, in plain sight, as stark reminder of my lens repair incapacity. So I could attempt to fix the Rokinon, or I could just cast it beneath the tread of a moving bulldozer. Either way, it likely would come out the same. |
|
Back to top |
|
|
visualopsins
Joined: 05 Mar 2009 Posts: 10959 Location: California
Expire: 2025-04-11
|
Posted: Fri Jun 29, 2012 6:13 pm Post subject: |
|
|
visualopsins wrote:
Please post photos of the lens front & rear & side (or links to photos). Those with experience opening lenses might have some ideas how the skilled may proceed.
Sounds like your best option is to have the lens repaired by a professional -- that or keep learning! _________________ ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮ like attracts like! ☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮☮
Cameras: Sony ILCE-7RM2, Spotmatics II, F, and ESII, Nikon P4
Lenses:
M42 Asahi Optical Co., Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200, Tele-Takumar 1:5.6/200, 1:6.3/300, Macro-Takumar 1:4/50, Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm, Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element), Super-Multi-Coated Fisheye-TAKUMAR 1:4/17, Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500, Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100, Super-Multi-Coated Bellows-TAKUMAR 1:4/100, SMC TAKUMAR 1:1.4/50, 1:1.8/55
M42 Carl Zeiss Jena Flektogon 2.4/35
Contax Carl Zeiss Vario-Sonnar T* 28-70mm F3.5-4.5
Pentax K-mount SMC PENTAX-A ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (151B), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto (Kiron)
|
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|