What lenses exist in EF/FD/M42 mount with a thread diameter down towards 37mm?
I have this 8x tele-extender with 37mm inner thread that I got surprisingly good result with on my old compact, and I would like to play around with it some more. I recently got FD and M42 adapters, so I have a plethora of possibilities. I figure there's no theoretical limit to how small a front element can be, but how small front threads have been manufactured in practice?
There might also be some that have a larger thread than is really necessary, and so would be more useful for this purpose. Any particular lenses of this kind I should know of?
Yes, I know I'll have manual focus and small aperture and vignetting and defects and stuff, but I'd like to toy a little more with it.
Thanks,
-Lars
within a certain marge you can use step-down rings,
kr
couplos
[quote name='couplos' timestamp='1293865787' post='5303']
within a certain marge you can use step-down rings,
kr
couplos
[/quote]
That's my initial plan, using my 50mm and 60mm lenses, but I'm hoping I can find a lens that gives less vignetting.
I wish there was a comprehensive lens database where you could search on such parameters as lens thread, but I'm not seeing one.
-Lars
[quote name='larsrc' timestamp='1293808601' post='5297']
What lenses exist in EF/FD/M42 mount with a thread diameter down towards 37mm?
I have this 8x tele-extender with 37mm inner thread that I got surprisingly good result with on my old compact ...
[/quote]
A 50-ish lens with such a small filter thread can not be
faster than f/2.8 .... an 8x tele-extender will make that a
400mm f/22 ... not exactly an overly useful combination methinks ...
or am I missing something?
Rainer
Surprisingly good results? I do not think so. Very low contrast, a LOT of "bleeding", very low sharpness... it does not make all that much sense besides just goofing around with it (CrystalVue 8x?).
genotypewriter
Unregistered
[quote name='larsrc' timestamp='1293808601' post='5297']
What lenses exist in EF/FD/M42 mount with a thread diameter down towards 37mm?
I have this 8x tele-extender with 37mm inner thread that I got surprisingly good result with on my old compact, and I would like to play around with it some more.[/quote]
I think you're wayyy better off getting an old native lens in the desired focal length than hoping for a 8x TC on a 37mm (read small aperture) lens.
Even the best lenses (e.g. over $5000) take visible IQ hits with a 2x extender that's made for those lenses. So an 8x TC on an arbitrary 37mm diameter (cheap and slow) lens should put you back in the field of cheapish compacts.
But here's a synthesised list of 37mm diameter lens configurations (in the typical f numbers) that you should look for:
180mm f/5.6 or slower
140 f/4 or slower
100 f/2.8 or slower
70 f/2 or slower
50 f/1.8 or slower
Since a 8x TC is really demanding on IQ and also reduces the apertures massively, I think a 100 2.8 lens should be a good bet. They're usually sharp, compared to wider angle lenses and with a 8x TC it should give you an effect of a 800mm f/22.
Also search on ebay for cheap f/11-16 type refractive zoom lenses. For example:
http://shop.ebay.com/?_from=R40&_trksid=m570&_nkw=420-800mm+lens
GTW
Hi Lars,
This comes close to a database of FD
http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlenses/index.htm
and this of FL lenses:
http://www.mir.com.my/rb/photography/companies/canon/fdresources/fllenses/index.htm
To my understanding FL are compatible with FD when used in stop down metering. But please confirm before investing.
Joachim
enjoy
