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04-04-2011, 04:51 AM   #1
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Removing the front ring of the 50mm 1.7 Auto Chinon

Well met!

I have a manual 50mm 1.7 lens that had dust and sand in it thus i decided to clean it up whilst waiting for my k-r to arrive

While not having any experience (it's the first lens i open up and clean) i decided to make a new post to show what was the most tricky part of the whole process from the novice's point of view:

Removing the front ring, opening up the way to the front lens element.

Also here on the Pentax forums there is a tutorial/discussion on this procedure with a 50mm 1.7 manual lens ( Thanks again guys!

I won't go into the details on how to disassemble and unscrew everything, you'll manage this by yourselves. As i said, for me the trickiest part was removing the front ring, mostly because i didn't know/visualize until finally getting it off how thick it is.

The orange tool (spray cap) was inspired from a video on youtube fellow pentaxian glee46 linked in another post:
, or search on youtube for: PENTAX-M 1:1.4 50mm Cleaning.

But enough talk, here are the images:

Will update with any worthy info in the future. At the moment waiting for the light grease for the focusing ring to arrive.

Best wishes!

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04-04-2011, 06:13 AM   #2
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Lens Ring Tool Kit, Gum Rubber 10 Pc.
05-23-2011, 02:54 AM   #3
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Has anyone worked on the front elements in the earlier non-mc version of this lens...?

I have a nice 55/1.7 Auto Chinon and I have removed the front ring and extracted the front element cluster but I cannot seperate the front elements from each other.
I have tried a compass-type tool in the two small holes at the back of the front elements but it won't budge...maybe it's glued...any suggestions on a safe glue solvent to try...?

Many thanks
05-23-2011, 05:21 AM   #4
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The lens elements of most early lenses were glued together with Canada balsam. To separate them, put it in a pan and cover it with water. Then bring the water to a boil. The boiling action alone will probably separate the elements after a few minutes.

05-25-2011, 01:30 AM   #5
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Thanks for the suggestion but the lens group is designed to unscrew I think.

There is a blob of clear (nail?) varnish locking a section - what is safe to use for softening the varnish lock...will nail varnish remover damage lens elements...?


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