_Karma_
Member
I recently bought a pentacon 135mm f2.8 lens of ebay for a pittance (zebra style casing too), but was disappointed to find it had a minor amount of fungus. I decided it would be better to try and clean it given the low cost and the experience it would give me.
Having no real previous experience I took photos as i went along and kept the pieces of the lens lined up in order. I was surprised how simply everything fits together and i soon had completely disassembled it. I however almost 2 tiny springs which shot out, so be warned to keep your hands covering whichever section you unscrew. I also didn't think to note the helicoid position so had much fun getting it to focus the full range again. (It turned out there was a groove which lined up with the infinity mark on the focus ring so it wasn't much trouble to realign, i guess this is how they assemble them originally). The only tools I needed were jeweller's screwdrivers (very small ones at that for one screw), and a piece of metal cut to size to act as a lens spanner wrench thing on a tighter lens.
I didn't really know if the cleaning was going to work but i was surprised. I just blew the dust of each element then dabs with 50/50 hydrogen peroxide and ammonia as i read somewhere. This actually got rid of the stuff fairly effectively. I also washed out the rest of the lens casings in a vague hope of getting rid of any dormant spores. Then i just used some 91% (i think) isopropyl alcohol to clean up the lenses and put it back together.
After this i had to wait a while for my m42 adapter to come and when it did I was disappointedly to find while it metered accurately in m mode av was off for no reason considering it is a preset lens. After a perusal of the webs I came across this "http: kmp . bdimitrov . de/technology/K-mount/Ka.html" site. Using the contact positions explained there I scratched the matching sections of my black anodized m42 (cheap non infinity one) to match and voilà I have accurate metering in av.
However, I cannot make contact with the recessed contact and was wondering it anyone had got any further with this. I'm curious whether pursuing this is worth it and if anyone has done it. The contact would have to be sprung but simply drilling through the m42 adapter then soldering/welding on a thin strip of bendy metal across the hole, and inserting a pin to make the contact.
Is there any real benefit of doing this? Doing it will allow me to dial in the aperture on av mode and it will meter as if the aperture was set to that, though you still actually have to manually set the aperture ring to that position if you want the reading to serve any purpose. I can see no reason. Any thought?
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http://www.flickr.com/photos/26674072@N06/
Having no real previous experience I took photos as i went along and kept the pieces of the lens lined up in order. I was surprised how simply everything fits together and i soon had completely disassembled it. I however almost 2 tiny springs which shot out, so be warned to keep your hands covering whichever section you unscrew. I also didn't think to note the helicoid position so had much fun getting it to focus the full range again. (It turned out there was a groove which lined up with the infinity mark on the focus ring so it wasn't much trouble to realign, i guess this is how they assemble them originally). The only tools I needed were jeweller's screwdrivers (very small ones at that for one screw), and a piece of metal cut to size to act as a lens spanner wrench thing on a tighter lens.
I didn't really know if the cleaning was going to work but i was surprised. I just blew the dust of each element then dabs with 50/50 hydrogen peroxide and ammonia as i read somewhere. This actually got rid of the stuff fairly effectively. I also washed out the rest of the lens casings in a vague hope of getting rid of any dormant spores. Then i just used some 91% (i think) isopropyl alcohol to clean up the lenses and put it back together.
After this i had to wait a while for my m42 adapter to come and when it did I was disappointedly to find while it metered accurately in m mode av was off for no reason considering it is a preset lens. After a perusal of the webs I came across this "http: kmp . bdimitrov . de/technology/K-mount/Ka.html" site. Using the contact positions explained there I scratched the matching sections of my black anodized m42 (cheap non infinity one) to match and voilà I have accurate metering in av.
However, I cannot make contact with the recessed contact and was wondering it anyone had got any further with this. I'm curious whether pursuing this is worth it and if anyone has done it. The contact would have to be sprung but simply drilling through the m42 adapter then soldering/welding on a thin strip of bendy metal across the hole, and inserting a pin to make the contact.
Is there any real benefit of doing this? Doing it will allow me to dial in the aperture on av mode and it will meter as if the aperture was set to that, though you still actually have to manually set the aperture ring to that position if you want the reading to serve any purpose. I can see no reason. Any thought?
--
http://www.flickr.com/photos/26674072@N06/
