Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-20-2016, 11:27 AM   #1
Senior Member




Join Date: Nov 2015
Location: Durban
Posts: 233
Sankyo kohki super komura unidapter 200mm f3.5 repair help needed

Hallo Pentaxians,

Has anybody disassembled/repaired one of these before that can advise or know where I can find a repair manual for same? I cannot find anything on the "net".
The problem is with the second lens element seemingly suffering from balsam degradation? noticeable along the outer edge. The barrel close to the lens element, both in front and behind, has also turned white, presumably as a result of the lens element problem. (See attached picture. #1 Indicating the barrel discoloration and #2 the white "haze" along the lens edge.)
Note: Bought the lens for the equivalent of about $20 so do not want to spend more than I paid for it to have it professionally repaired.
Any advice/help would be appreciated.
Regards.

Attached Images
View Picture EXIF
Lumia 532 Dual SIM  Photo 
12-20-2016, 11:38 AM   #2
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 15,027
@DCShooter - Brian do you have any ideas?
12-20-2016, 03:47 PM   #3
Pentaxian




Join Date: Dec 2009
Location: Dallas / Yucatan
Posts: 1,044
I love trying out older lenses on my various Pentax bodies.

Since you paid $20 for this lens and it was originally intended for a full frame camera, if you are using it on an APS-C body, the issues on the edge of the lens -- as you illustrated -- will very, very likely have zero effect on your images. Unless there is hazing across the center of the elements, ignore the issue?

That said, I believe the front filter ring bezel unscrews to access the front elements. Usually a rubber stopper or disk (Rubber stopper example: https://www.amazon.com/Japan-Vacuum-Camera-Opener-Repair/dp/B0013HFYKK/ref=p...AZFTG2HQSJNE8X) can be used to 'grip' the inner bezel to get it to turn, but on older lenses, things tend to be stuck tight. [NOTE: I am not recommending you follow these steps, I'm just mentioning some ways by which older lenses come apart!]

I'm not sure if you access the remainder of the elements through the front (you'll likely need a spanner wrench to unscrew an internal slotted ring if so, similar to something like this.... Amazon.com : Neewer Professional Flat & pointed Tips DSLR Camera Lens Spanner Wrench Repairing Opening Tool for Most Cameras : Camera & Photo).

OR, the rest of the elements are reached by disassembling the rear of the lens. Likely there are set screws which hold rings in place which unscrew, but be careful of the aperture blades.

OR, (sorry, I haven't taken apart that specific one), you will have to remove screws from the focus ring, remove it, unscrew the helicoid... the lens comes apart in the middle...., then it's a bit complex to get it all back just right and properly adjusted for infinity focus.

For $20, using on a crop-sensor camera, just use as is and the defects likely have no effect on your images. The tools alone are more than the cost of the lens.

Update: This isn't the same lens, but roughly the same era and concept, but not likely to be identical in all aspects:

https://www.pentaxforums.com/forums/114-maintenance-repair-articles/335449-su...bly-guide.html

Last edited by yucatanPentax; 12-20-2016 at 04:13 PM.
12-21-2016, 06:45 AM   #4
Senior Member




Join Date: Nov 2015
Location: Durban
Posts: 233
Original Poster
QuoteOriginally posted by yucatanPentax Quote
I love trying out older lenses on my various Pentax bodies.

Since you paid $20 for this lens and it was originally intended for a full frame camera, if you are using it on an APS-C body, the issues on the edge of the lens -- as you illustrated -- will very, very likely have zero effect on your images. Unless there is hazing across the center of the elements, ignore the issue?

That said, I believe the front filter ring bezel unscrews to access the front elements. Usually a rubber stopper or disk (Rubber stopper example: https://www.amazon.com/Japan-Vacuum-Camera-Opener-Repair/dp/B0013HFYKK/ref=p...AZFTG2HQSJNE8X) can be used to 'grip' the inner bezel to get it to turn, but on older lenses, things tend to be stuck tight. [NOTE: I am not recommending you follow these steps, I'm just mentioning some ways by which older lenses come apart!]

I'm not sure if you access the remainder of the elements through the front (you'll likely need a spanner wrench to unscrew an internal slotted ring if so, similar to something like this.... Amazon.com : Neewer Professional Flat & pointed Tips DSLR Camera Lens Spanner Wrench Repairing Opening Tool for Most Cameras : Camera & Photo).

OR, the rest of the elements are reached by disassembling the rear of the lens. Likely there are set screws which hold rings in place which unscrew, but be careful of the aperture blades.

OR, (sorry, I haven't taken apart that specific one), you will have to remove screws from the focus ring, remove it, unscrew the helicoid... the lens comes apart in the middle...., then it's a bit complex to get it all back just right and properly adjusted for infinity focus.

For $20, using on a crop-sensor camera, just use as is and the defects likely have no effect on your images. The tools alone are more than the cost of the lens.

Update: This isn't the same lens, but roughly the same era and concept, but not likely to be identical in all aspects:

https://www.pentaxforums.com/forums/114-maintenance-repair-articles/335449-su...bly-guide.html
Thanks for your response and general directions on disassembly of "similar" or same era lenses, yucatanPentax.
Like you, I enjoy using these older, manual lenses on my K-50 and have a couple of Takumar primes as well.
This Komura is a well-constructed, solid lens and stopped down to f8 produces nice, sharp images. Wide open at f3.5 and also at f4 and f5.6 the images are in my opinion excessively soft. Even though fixing the mentioned issues may or may not improve it's performance, I would still like to restore this oldie to as close to it's original condition as I can.
Best.

12-21-2016, 10:17 AM   #5
Pentaxian




Join Date: Dec 2009
Location: Dallas / Yucatan
Posts: 1,044
This fellow has disassembled a Komura 90-250mm zoom, somewhat newer than your lens, perhaps. From looking at the parts, you can see that the front retaining ring comes off and that further elements were accessed via at least one other retaining ring inside. Likely, set screws were removed from the focus grip and aperture ring to remove those. At least a few ideas can be gleaned from the disassembled photo:

LENS REVIEW: Super Komura 90-250mm f/4.5 | Photo Journal by Rattus Yu
12-22-2016, 09:33 AM   #6
Senior Member




Join Date: Nov 2015
Location: Durban
Posts: 233
Original Poster
Thank you for your further input, yucatanPentax. For a first-time lens-tinkerer every bit helps :-)
Best.
12-25-2016, 12:42 PM   #7
Senior Member




Join Date: Nov 2015
Location: Durban
Posts: 233
Original Poster
Valuable information and advise about disassembly and repairs on this lens, DCshooter; many thanks! I have some other old lenses that also need attention so I've invested in the necessary tools.

I doubt that it is "schneideritis", but some paint has certainly come off the inside of the tube/ring containing the second element, in front of as well as behind the lens. Attached a picture with light from the rear of the lens that may give you a better idea of the white "haze" along the outer edge of the lens (indicated with arrows).

Circled in the picture are two fungus spots that I also want to address at the same time.

The support from yourself and yucatanPENTAX just emphasized the spirit and attitude of members of this forum!
Best.
Attached Images
View Picture EXIF
PENTAX K-50  Photo 
04-06-2017, 01:02 AM - 1 Like   #8
Senior Member




Join Date: Nov 2015
Location: Durban
Posts: 233
Original Poster
Update on this issue. Armed with tips and advice received here, I managed to disassemble and clean the lens properly. The main issue turned out to be "scneideritis?" on the third lens element as @dcshooter suggested. The flaking paint was removed and the edges repainted with a sharpie.

Like they say: "The proof of the pudding lies in the eating." I am well satisfied with the results and the fact that this "oldie" can once again perform to its potential.

Link: Super-Komura Uni Auto 200mm f3.5 Test Photos | Flickr

Best.

04-06-2017, 08:08 AM   #9
Pentaxian




Join Date: Dec 2009
Location: Dallas / Yucatan
Posts: 1,044
QuoteOriginally posted by Charlie Victor Quote
Update on this issue. Armed with tips and advice received here, I managed to disassemble and clean the lens properly. The main issue turned out to be "scneideritis?" on the third lens element as @dcshooter suggested. The flaking paint was removed and the edges repainted with a sharpie.

Like they say: "The proof of the pudding lies in the eating." I am well satisfied with the results and the fact that this "oldie" can once again perform to its potential.

Link: Super-Komura Uni Auto 200mm f3.5 Test Photos | Flickr

Best.

Thank you for the update. I was wondering how it all went. Seems the images turned out well too. Thanks!
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!
200mm 3.5, 200mm f3.5 repair, barrel, disassembly, element, kohki super komura, komura, komura unidapter 200mm, lens, pentax service, repair, sankyo kohki, service, super, unidapter, unidapter 200mm f3.5, warranty
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Super Carenar 200mm f3.5 on Goodwill Auction.......somewhat Rare Dlanor Sekao Pentax SLR Lens Discussion 4 07-02-2016 03:57 AM
AF360FGZ Repair - Help Needed! Kozlok Flashes, Lighting, and Studio 11 05-17-2016 09:37 AM
Help needed - Pentax-A 35-105mm f3.5 deepbluish Pentax SLR Lens Discussion 26 01-16-2016 04:49 AM
Help with repair Pentax A 35-105mm f3.5 sekelsek Pentax SLR Lens Discussion 7 08-31-2011 06:39 PM
135 f3.5 Super Takumar help Id akfreak Pentax SLR Lens Discussion 3 06-21-2010 04:20 PM



All times are GMT -7. The time now is 02:10 AM. | See also: NikonForums.com, CanonForums.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