Chuck, your memory serves you well, they are 8mm lens.
Quoting John Shaw's book (page 126 for those following along:)
"For the best results you should use a reversed movie-camera lens for subjects
that are the actual size of the of the original film format or smaller. In
other words a lens from an 8mm camera can be reversed for 7X or higher
magnification, while that from a Super-8 can be used at 6X or more"
So you are correct, using the larger format would produce a lower magnification.
But if you follow Mr. Shaw's theory, a 16mm lens would be for a subject 16mm or
smaller. If I was shooting an object that was 16mm across I'd be in the 2X
range of magnification. I can do that in a couple of ways:
On the 65-116 tube you can get the following subject size @ distance
With the tube at 65 / 116
50mm lens 24 @ 54 / 15 @ 37
35mm lens 17 @ 23 / 10 @ 18
28mm lens 14 @ 10 / 8 @ 3
24mm lens 13 @ 5 / To close
And reversing the lens
50mm R 18 @ 65 / 12 @ 55
35mm R 12 @ 47 / 8 @ 45
28mm R 8 @ 39 / 6 @ 38
24mm R 7 @ 40 / 5 @ 40
I stole that information from Wim Verheyen's site at:
http://users.skynet.be/aemit/photo/macro.html
Check it out, it's better formatted than my text.
As Wim points out:
Reversing a lens gets higher magnification with greater subject distance and
better quality but with the loss of the auto aperture.
However, if you use the bellows and reverse the lens board you can still use a
dual cable release and maintain that auto aperture. Score one for Olympus.
But for those who have a thirst for the itsy bitsy, when I mount that 6.5mm
Raptar on my bellows at full extension, I am getting near 36X magnification.
It's not great quality but it does have some bragging rights. I don't have the
20mm macro and I am sure that the quality of the shots taken with it would
probably be better and easier to shoot with the 20mm, but that cine lens was a
lot cheaper.
Jay - a cheapskate OM'r if there ever was one.
>From memory of my father-in-law's 8mm movie camera these sound like 8mm lenses.
>I thing his lens was 12mm. Can one readily find longer focal lengths from 16mm
>cameras so as not to have such high magnification? Maybe 16mm lenses run
>towards the 12-36mm range?
>
>Chuck Norcutt
>>Jay Drew wrote:
>>
>>Wayne raised the question as to what cine lens did I use (reversed) on my
>>bellows (and extension tubes).
>>
>>It was basically choosing a cine lens that would provide an easy mounting
>>scheme. What I wanted was a lens that had threaded ring that I would guess
>>enabled a drop in filter to be inserted and then the ring screwed back in to
>>hold that filter in place.
>>
>>My method of mounting was to take the female portion of a metal 49mm filter
>>stack cap and make hole in the center of it that would accommodate the
threaded
>>male portion of the cine filter capture section. I then was able to screw the
>>lens and filter holder together pinching the stack cap between the two pieces.
>>I then use a 49mm reverse mount and screw the cine/stack cap onto it, and
mount
>>that onto the bellows/tubes what have you.
>>
>>I use a Wollensak Raptar 9mm, 6.5mm and a Wittnauer Chronostar at 13mm. The
>>Wittnauer was 8 bucks at a surplus store.
>>
>>The 6.5mm is really difficult to deal with, the depth of field is just about
>>nothing. The 13mm on my 65-116 tube was giving me a 9X magnification.
>>
>>Maybe Dean Hansen will pipe up, we traded notes once and he mentioned using an
>>Elgeet 7mm reversed and getting 12x directly on the camera. I've got the
>>distinct feeling he's gotten much higher quality shots than I have.
>>
>>The price is a lot cheaper than a 38mm or a 20mm, but you do lose the auto
>>diaphragm and the quality is not superb. Lighting is tough. But it is cheap.
>>I got the idea from John Shaw's book Closeups in Nature.
>>
>>Jay
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