Advice Sought C-Mount N00b!

[Kram]

I'm considering buying my first C-mount lens. Are there any issues adapting them to Canon EOS bodies? I'll be using it on a 60D and mainly doing close focus (don't need infinity).

I see a cheap Chinese adapter on ebay, any preferences?
Any advice greatly appreciated.

[kds315*]

I haven't used that combination, as the useful image circle of c-mount lenses is usually limited to what they were once made for, 16mm film - only quite long focal length might project a much larger image but that can only be found out experimentally i.e. trying it out.

If you only like to do macro with these lenses, they should be reversed actually (except if they are symmetrical designs). Lefkowitz in his well known book describes that quite well, as it once was a cheap alternative to highly specialized and pricey macro lenses. You would need an adjustable helicoid in M42-M42 version, a M42 to Canon EOS adapter and to mount the lens, an adapter M42 to front filter mount of that specific c-mount lens which in most cases would need to be made. That would allow for higher magnifications.

Lefkowitz, Lester, "The Manual of Close-Up Photography", Amphoto N.Y., 1979, ISBN 0-8174-2130-0

Here is a guy (Pete Ganzel) who tried similar: http://www.pbase.com/pganzel/macromicro_add_ons

and here what famous Nikon shooter Bjørn Rørslett fabricated: http://www.naturfotograf.com/roll_your_own_lens.html

Have fun!!

[iangreenhalgh1]

C-mount lenses are a poor solution for an EOS, they will probably not cover the sensor fully, as Klaus says, the longer ones might but but might not.

There are some better options for Macro work on EOS imho, I got an excellent condition 55mm Micro-Nikkor for 28ukp recently, that lens will out-perform any c-mount lens for macro imho.

[kds315*]

Mark wants them only for macro and for that cmount lenses WILL work, if reversed.

[iangreenhalgh1]

Does the image circle increase in size if reversed?

Enlarger lenses I find are great for macro, Schneider Componon-S 100mm is a personal fave, Schneider sell it for 1500 dollars with 'macro' printed on it, I got mine for less than 10ukp. I use it on a set of Russian M39 bellows with an EOS-M39 converter on the rear of the bellows, works great, bellows were 6ukp.

[kds315*]

Why had I proposed to read a book about optics?? Not to intimidate and certainly not to lecture, just so such questions would not be necessary...

Here's an interactive optics simulator, to try all that out...no math involved, just play with it
http://buphy.bu.edu/~duffy/java/Opticsa1.html

[Kram]

Thnaks very much Klaus and Ian for the great information! I will definitely read the links. I love to experiment and will give it a go and report back.

You guys are the best!

BTW, I do have some high quality macro lenses but I also like something unusual and perhaps unique.

[ZoneV]

Probably we need to define macro a bit closer?
There are "definitions" that say macro is only till 1:1 - other like the German DIN standard go up to 10:1

With a reversed shorter C-mount lens (e.g. 16mm) I get magnified images.
With a reversed long C-mount lenses with for example 50mm focal length I get macro images that are not magnified - image of object is smaller than the object.

With too much extension tubes, like with a helicoid and the adapters, one probably get no more sharp image, because "focus" is inside the lens!

[iangreenhalgh1]

Thankyou ZoneV, that makes sense.

Now I'm thinking, a Jupiter-12 reversed could make an interesting macro lens, being a non-retrofocus Biogon design.

[kds315*]

[iangreenhalgh1]

Klaus, please try to be less condescending, you seem to get annoyed whenever people who don't have an extensive education in optics asks a question.

Quite clearly the OP only has a base level of knowledge, as do I and many others, we don't benefit from constantly being told to read expensive books.

If you find it so annoying to discourse on a base level, perhaps you should refrain from doing so?

[kds315*]

I'll certainly take your advise, but just to explain, the unwillingness to learn it was upsets me, so I do excuse for the tone, which might have inappropriate. Btw. knowledge about optics does not involve reading expensive books, most can be had for free on the net.

[ZoneV]