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Evisc
Tinkerer
Username: Evisc
Post Number: 26
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 20, 2008 - 01:13 pm: | 
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Not strictly a repair question and maybe a long shot, but I'm planning on adapting a sonnar 180 mm 2.8 (for the pentacon six etc.) for my beloved SL66. I know there is the issue of the SL66 having a longer register distance 102.8 mm than the Sonnar 74.1 mm, but it has been done (http://sl66.com/pg/sl66_lenses/zeiss180.htm). Seems it should be possible to remove the parts of the back of the lens and mounting the lens partly intruding into the SL66.
Any thought? Any at all? |
Glenn
Tinkerer
Username: Glenn
Post Number: 466
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 20, 2008 - 06:52 pm: |
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The 180/2.8 Sonnar is quite adaptable. However unless you have a well equipped workshop, the end result could well be a pile of useless bits.
You first have to ascertain how much or what, needs to be removed from the outer barrel - to allow accurate measurements for machining of the barrel or spacer rings I use a fixture/jig. This supports the lens (focused at infinity) by the filter threads and has a plate with a circular cutout that abuts the original register surface on the lens, the new register position is then 'marked off' from this plate by a threaded rod with a small pointer marking the new register position. One then removes the lens from the jig and strips out the optics and original mount. Remount the barrel assembly in the jig using the filter threads, and you can then work out how much machining etc is needed to locate the SL66 mount correctly on the barrel. If you construct the jig properly and measure the location of the rear plate and new register position accurately, you can actually machine a barrel or any spacers etc to the exact dimension. The use of shims behind the new mount can correct the odd few thou under correct length if one is not that accurate.
I use the above jig for all my major lens hacking, but have not done the 180 Sonnar/SL66 combination. You may only have to machine up a suitable location piece to position the SL66 mount on the stripped down barrel. The alternative to home engineering, is to have one of the firms that specialise in lens modification do the job. They will probably have all the dimensions already worked out, so the job will be simple and cost effective. |
Evisc
Tinkerer
Username: Evisc
Post Number: 27
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 20, 2008 - 09:39 pm: |
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Hmmm... A little discouraging, that is... Still kind of think it might be a matter of removing the outer covering in the back part of the lens... But if I'm wrong do you have any firms that do lens hacking you could recommend?
Thanks! |
Lucas
Tinkerer
Username: Lucas
Post Number: 83
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 21, 2008 - 04:16 am: |
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Whoever did that transformation "lost" the complete auto diaphragm mechanism to make room for the SL 66 adapter ring. Looks like a very nice job in machining. This is only possible for someone with a fully equiped metalshop |
Glenn
Tinkerer
Username: Glenn
Post Number: 467
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 21, 2008 - 10:20 am: |
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Elan,
No you are way out. As Lucas states; the whole auto diaphragm mechanism is removed, with the stopdown/preview pin locked in the 'stopped down' position to give the manual operation of the diaphragm. If you were familiar with the construction of this lens, you would understand what is required. Whilst I said that I had not done a SL66 conversion, I have altered a number of 180 and 120 Zeiss 2.8 Sonnar lenses to fit various slr bodies over the years. So my comments were based on practical experience and not hypothesis.
I am based in the UK, so only have knowledge of firms here that could help. However I have seen mention of US firms that do this type of work - can you trace the company/person who did the alteration to the lens illustrated in your link? I suggest you try and track down this source, it may be your easiest route to obtaining your desired lens fitting. |
Evisc
Tinkerer
Username: Evisc
Post Number: 28
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 21, 2008 - 12:04 pm: |
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Was doing some wishful thinking back there;) As for the matter of firms that do these kinds of jobs; I will try, as you suggested, to track down the ones that did the one in the picture. And firms in the UK is just as well as firms in the USA (me being based in Norway), so any UK firms that you could suggest would be great!
Thanks |
Lucas
Tinkerer
Username: Lucas
Post Number: 84
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 21, 2008 - 02:07 pm: |
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the kind of money you will be spending could keep you in P6 bodies for the rest of your life. Or get you a very decent piece of Rollei glass.
I did one for a pentacon 4/300 for P6 in steel, way too much work.
http://farm4.static.flickr.com/3230/2844001264_b37e2dfb30_o.jpg |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 748
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 22, 2008 - 06:00 pm: |
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It sounds like an interesting project for your engine lathe, milling machine and rotary table.... post a photo of it when you're finished! |
Evisc
Tinkerer
Username: Evisc
Post Number: 29
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, December 25, 2008 - 07:19 pm: |
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Ditto Oleson! Myself, I'm putting the project on ice for now. I'll be sure to post something if I decide, against reason, to try my hands on som enginering;) |
