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Pentax Lens Disassembly Database
Posted By: Chaos_Realm, 03-22-2012, 05:04 PM

Hi all,
I have recently been on the hunt for dis-assembly guides for the purpose of dust removal etc. They seem to be turning up in various places across the forum, so I plan on creating a list of all the Pentax lens disassembly posts here. I will categorise each lens like they are in the 'lens database' and you should be able to see which lenses have a guide and which do not. If I come across multiple guides then I will list them all under that lens so there is coverage or alternative explanations. And hopefully with your help we will be able to put together a substantial resource for the DIYer's here, although I do realize some lenses will never have an owner brave enough to strip down themselves due to the shear value. I know this will take quite some time but I think it will be worth it. I have restricted time at this point but I want to get the ball rolling. So here is what we have:

NB: Currently this tread is only for Pentax K-Mount & M42 Screw-mount lenses. Maybe once this has developed a bit I might look at introducing other pentax Mounts and or third party lenses and permitting time (and success of this resource) a cleaning guide with tips on tools and techniques. I am trying not to bite off more than I can chew for the moment so we will just stick with lenses listed below.

Digital Era K-mount Lenses Film Era K-Mount Lenses
M42 Screw Mount Lenses

Last edited by Chaos_Realm; 04-22-2017 at 07:27 PM.
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5 Days Ago - 1 Like   #166
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What you're probably talking about is the introduction of "color centers" in the glass caused by the radioactive nature of the Thorium (and possibly some of the rare earths or other doping substances used in the glass formula).

There's an industry devoted to coloring diamonds using radiation (the diamonds are placed in a nuclear reactor). In the case of glass, the reaction can be reversible (hope not for diamonds - your girl's favorite chocolate colored diamonds just faded - yikes!!). Since the Thorium is in intimate contact with the glass, its radiation is fairly intense at atomic distances.

The same effect is responsible for turning old glass purple tints (those old purple bottles on the antique store shelf) and some glass bluish-green (telegraph pole insulators) due to sun exposure and the presence of some elements in the glass (newer glass is resistant to this).

I once radiated vegetable seeds in a cobalt (gamma) cell and my clear plastic containers came back purple (seeds came back dead)

For more if you're interested (heavy stuff):

Activation of color centers in Glass

Last edited by Bob 256; 4 Days Ago at 08:45 AM.

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