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CHINON / Tomioka 1.4/50mm PK complete overhaul
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PostPosted: Tue Jun 07, 2011 2:45 pm    Post subject: CHINON / Tomioka 1.4/50mm PK complete overhaul Reply with quote

Here's the thingy i received as defect for half price. Branded Revuenon but the same lens as Chinon made by Tomioka. Defect truly it was. F-stop started at 4, there was no clicks, grease was everywhere and filter was bent enough label ring could not be removed.

Step 1: bend the filter into "correct" position
Step 2: drilling the holes to remove label ring, vacuum off the residues
Step 3: remove label with spanners



Step 4: unscrew two little screws - you can see lens soaked in grease



Step 5: UNSCREW CLOCKWISE! contrary to all others



Step 6: If you only want to clean under front glass cut off all the glue around thin ring; skip two steps otherwise



Step 7: Use some cool round rubber to unscrew



Step 8: There was some grease on aperture blades too. I didn't remove front glass yet. Front system had to go off fully.

Since i didn't do no testing of the lens yet i tried it on camera to see if lens was giving proper picture. It already happened to me i repaired a lens that had some other defect then obvious. This step prevents pointless work.

Under front ring i found sand and dirt to grow plants in.



Step 9: Grab the ring bellow thin front one with spanners. Unscrew. Sucks if stuck due to glue.



Step 10: Put front system off. Now you can already touch the blades. Unscrew 5 screws at back to put mount and aperture ring off too. Watch for the small ball. It was missing here. On second photo you can see the grease from focusing mechanism on aperture moving lever. Terrible!





Step 11: Unscrew back lens system. Here the blades! Luckily i was able to clean the small amount of grease already in the system with Isopropanol and cotton buds plus a bit of graphite pencil boost. This was last moment save.



Step 12: Dishwashing (don't forget to vacuum out and hair dry later)





Step 13: I replaced the ball to enable F-stop clicking. Put the back lens system back. I was happy to see it's clean inside.



Step 14: Worst part. Cleaning front glass system. Opening thin rings was close to impossible due glue. Front and back has to be opened.
Cleaned and re-assembled without dust. Little advice: put back first the front glass. Prepare bottom two on pedestal and move front one over them.



Step 15: Adjusting the infinity by releasing top three screws and moving focusing ring to proper position. Safety glue the screws when done. I like to adjust infinity a hair over / past.



Step 16: A bit of make-up if required. And the lens is ready to rumble!

I am putting it into marketplace. Perhaps i can find a poor soul who wasn't appalled by seeing this ugly procedure Cool





PostPosted: Tue Jun 07, 2011 3:15 pm    Post subject: Reply with quote

Great post Pancolart - thanks Smile


PostPosted: Tue Jun 07, 2011 6:58 pm    Post subject: Reply with quote

Very fine tutorial, thanks for sharing ...