Source for Enlarging Lenses

C&H Sales lists Olympus lenses that were originally intended for a microfilm reader, according to the catalog. Of particular interest to the Minoxer are the 26.2 and 41.17 mm focal lengths. The 26.2 produces an easy 8x10 on my Omega D-2, and the 41.17 is good for 4x5s and 5x7s. These lenses appear to be designed to project from a flat film surface to a flat viewing surface at a high degree of magnification -perfect for enlarging tiny negatives. This does mean that the lens can only be installed one way around, and this is not in any way indicated on the barrel. The end with the LARGER element goes toward the FILM - trial and error ;-). You will have to cobble up some kind of lensboard adapter (I made mine from aluminum). The best part is the price, $7.50 US. Disclaimer: I have no interest in C&H except as a customer.

<P>It is a great idea to convert microfilm projector lens into 8x11

enlarger lens.<P>But what is the address or contact phone number of C&H? <P> Other sources of 8x11 enlarging lens include:

<Ul>

<LI> Projector lens from Minox projectors such as Minotact, HP 24, HP 30 projectors. Some Minoxers use Minox projectors to enlarge

16x20" prints.

<li> Kodak disc camera aspheric glass lens-- reputed to have very

high resolution.

<li> 16mm movie camera lens

<li> Tessar 23mm/2.8 lens from dead Rollei A110/E110

<li> Tessar 25mm/2.8 lens from dead Rollei 16<P></ul>

Thanks for the idea of using a microfilm reader lens. I tried a Canon

lens B06 (no focal length given, but according to the manual the

magnification factor is 41x when used as intended). It is sufficient

for making at least 8"x10" enlargements with a tiny Durst 301

enlarger. The lack of aperture settings is a little problem, because

the depth of field is almost non-existent and the exposure times are

very short.

<P>Ari, 41x from 8x11mm negative will give you about 13x 18", more than

sufficient for 8x10".

Minox enlarge lens also has no aperture, instead is used at wide open. If exposure time is too short, you may use ND filter to lengthen the exposure time, or use a light bulb of lesser watt.

<P> Depth of field is very shallow, that should not a problem if the lens

is threaded and use its barrel to focus intead of a bellow. <p> You may try to move the easel in addition to moving the lens to focus; there is great depth of field at the easel !

I remember reading somewhere that Minox once was also making

Microfiche reader.

Some high quality 35mm camera lens may be used for enlarging Minox 8x11 negatives. For example

<ul>

<li> Carl Zeiss Planar 50mm/1.4, top resolution at 95 lpmm

<li> Leica Macro -Elmarit 60mm/2.8 72 lpmm

<li> Micro Nikkor 55mm/2.8 68 lpmm

<li> etc

<ul>

It is not necessary for 8x11 enlarging lens to have 1:1 or 1:2 macro capability, because usually the smaller size 3.5x 5" prints is about 15x. <P>> The problems with using 35mm lens as 8x11 lens are a) resolution not as good as Minox enlarging lens, and b) enlarger head too high, for instance for a 55mm lens, one has the raise the enlarger head 88 cm above easel.<P> BTW, recent Popular Photography tested Zeiss Planar and Leica Summilux 50/1.4 are two sharpest standard lenses.

For enlarging Minox 35mm negatives, non macro camera lens is not qutie suitable; for example, Zeiss Planar has quite a close focusing range of 45cm or 8x magnification; for 35mm negative, this means at least 8x12" enlargement.<p> If you want 4x6" or 4x magnification, then it is outside the

designed range, and the abberations will not be well corrected. <p> Hence for 35mm negatives, macro lens is suitable.

Why Minox lens be use as an excellent Minox enlarger lens?

<p> Because the magnification range of Minox lens matches closely

the magnification range of Minox enlarger, beginning at slightly more than 12 x.

<p> As a matter of fact, 8" 'close focus rnage" is only "close" for people used to

35mm camera. Acutally at about 12 x, Minox camera lens is not a macro lens at all, it is equivalent to a standard 50mm lens with close focusing range of 65cm.

In the early 60s, there were all kinds of enlarger lenses for Minox for example

<ol><li> 35mm/ f3.5 Mirar lens for Axomat enlarger <li> 25mm lens for Beseler,

<li> Rodenstock Trina 20mm /f2.5 <li> Minolta Rokkor 25mm f/2.8

<li> Wollensak 25mm f/3.5 <li> Timble 25mm f/3.5

<li>Goldammer Goldeck 16 camera lens: Color- Ennit 20mm 1:2.8.

Aperture from click stop from 2.8 to 16

made by ENNA Munich </ol>

<p> I bought the screwmount Goldeck 16 camera Color -Ennit on eBay from a seller from Germany.