Cutting a lens down and a camera adapter

Greetings digital camera owners,
I recently posted questions about cutting down a lens O.D. on the optics newsgroup. I posted to metalworking dot com some text and 4
pictures showing a camera adapter and adapter rings for a Cybershot DSC-W120 along with a picture of the achromat lens I cut down and the tools used to do the cutting. Also in one of the pictures is shown the annulus left over from the cutting down process. Advice from the optics newsgroup was instrumental in my attempt to cut a smaller lens out of a larger one. I was successful on my first try. I used diamond paste and a bronze hole saw to cut the lens which was mounted in an aluminum chuck and held there with dopping wax. The files are called: http://metalworking.com/dropbox/lensadapter.txt
http://metalworking.com/dropbox/lensadapter1.jpg
http://metalworking.com/dropbox/lensdadpter2.jpg
http://metalworking.com/dropbox/lensadapter3.jpg
http://metalworking.com/dropbox/lensadapter4.jpg
Now I need to figure out which telephoto lenses can be used with my camera. I'd like to find a telephoto lens that I can take apart and use the glass to make a collapsable lens. Since the camera already has a 4x zoom feature the tele lens doesn't need to be a zoom type. Cheers, Eric
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Add-on "telephotos" are basically just a low-power Galilean telescope that sits in front of the camera lens. I expect you will be disappointed with the quality, as stacking lenses in this way can only degrade performance, and the typical add-on is not well corrected.
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Do you have the dimensions for a Canon A540 mount so I can machine a microscope adapter?
Jim Wilkins
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Jim Wilkins writes:

See two pages here:
http://www.truetex.com/canon_a540_bayonet.pdf
However, the Chinese off-the-shelf item is extremely cheap nowadays:
http://search.ebay.com/search/search.dll?satitle 40+adapt*+-ac+-power
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On Wed, 04 Mar 2009 00:37:35 -0600, Richard J Kinch

So is there any type of lens that would work? ERS
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This sounds like a lot of work. You could have probably had a little chat with an optician at one of those glasses in a hour place and had him grind down the OD in about 3 minutes. Probably a barter for a bottle of scotch.
--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
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On Wed, 4 Mar 2009 20:21:13 -0800, "Roger Shoaf"

Cutting down the lens took about half an hour. Making the chuck and core drill took about 15 minutes. And it was fun. ERS
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Good, I am glad you had fun, but is the optical center of the lens in proper alignment?
What the optician does is to stick on his chuck plate in relation to the optical center of the lens. While the lens you had was probably centered, it could have been off center a bit and this would cock the optics and give you a fuzzy resolution. You can probably get a good idea by measuring the edge thickness at several places around the edge.
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Roger Shoaf
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