[amosdjunaidi]

My new acquisition to go alongside a Leitz Portugal Colorplan 90mm 2.5 from Jean Poitiers .

From what I’ve read they have different optical designs - the earlier silver one has 5 elements 4 groups, and the black one 6 elements 4 groups. Haven't used the German one in earnest, except to test it, and it has a different min/max focus distance. If it's as sharp and colourful as the Portuguese, I'll be very happy.



Here are some recent photos from the Portuguese one.

very nice pics....

do you have the pic of that lens with the helicoid? i just want to adapt that lens. it's still on the way

thank you

[barondla]

K-1 + Leica Colorplan-P 90/2.5 slide projection lens mounted in a Russian macro bellows ... bees in my backyard early this evening

Fabulous images! The first one looks holographic. Such a beautiful rendering. Well done.

I have this lens on a Leica Pradovit slide projector. It's the solid silver version and will end up on a camera as soon as time permits. Can't wait to give it a try.

Thanks for sharing,
barondla

[barondla]

X posted from medium format F2.8 or wider lens club.

First post of a Leica 90mm F2.5 Colorplan (original silver) adapted to Pentax 645Z. The lens barrel was wrapped in corrugated cardboard and shoved into an aftermarket P67 to P645 lens adapter. No way to align optics parralel to sensor or keep them there. The lens would sag after a short time. I'll have to work on that.



Thanks for looking,
barondla

[Thagomizer]

X posted from medium format F2.8 or wider lens club.

First post of a Leica 90mm F2.5 Colorplan (original silver) adapted to Pentax 645Z. The lens barrel was wrapped in corrugated cardboard and shoved into an aftermarket 645-67 lens adapter. No way to align optics parralel to sensor or keep them there. The lens would sag after a short time. I'll have to work on that.



Thanks for looking,
barondla

A very striking result! I've got a few projector lenses I should do more with. I recently deglassed a surplus Vivitar 2x Macro focusing teleconverter to convert it into a helicoid, which would make a more rugged mounting option than the bellows I've used in the past. Your "carboard adapter" sounds like a good, rough and ready solution for putting things together. I'll keep it in mind if I have any gaps to fill in my experiments.

[barondla]

A very striking result! I've got a few projector lenses I should do more with. I recently deglassed a surplus Vivitar 2x Macro focusing teleconverter to convert it into a helicoid, which would make a more rugged mounting option than the bellows I've used in the past. Your "carboard adapter" sounds like a good, rough and ready solution for putting things together. I'll keep it in mind if I have any gaps to fill in my experiments.

Thanks for the kind words. Get those lenses out and play! The 2x converter conversion is a good idea. It jogged my memory that there are 2 extra 645 extension tubes sitting at home. They should add more support vs the lens adapter.

Thanks,
barondla

[zubzubadoodle]

For this months 'Single in...' challenge I'm using an Ernst Leitz Dimaron 10cm f2.8 Projector Lens. It has a very narrow depth of field and the focus point is well in front of where the K1 thinks it is. So focussing has to be done by eye and if you sway back or forward by even the tiniest bit you lose the focus.
To improve this I have taped a bit of card to the front of the lens and cut a 12.5mm circle in it. This should give me f8. Due to a defect in the manufacturing process (i.e. I messed up with the scissors) the hole is a bid raggedy, so It's probably between f5.6 and f8. That has made a huge difference, it's so much easier to use now.

Here are a few at f2.8







and one at f5.6ish



the album is here if you would like to see more.

[scratchpaddy]

I don't know why I haven't joined this club sooner. This is fascinating. For my first attempt, I bought a 16KP-1,2/50 from Ukraine along with a macro focusing helicoid from China, and designed a 3d-printed piece to connect the two. The lens uses the same basic "planar" lens formula as the Helios lenses. It's like a Helios 44 that goes to f/1.2 instead of just f/2.



Made for projecting 16mm movies, obviously it does not cover "full frame," but it's usable in that format for extreme-isolation portraits, where the subject is centered and everything else is an abstract swirl.



Unfortunately the back of the lens needs to sit 16mm from the sensor for infinity focus, ruling out use with mirrored cameras.

[scratchpaddy]

Got another, which I know others have featured in this thread before. 100mm f/1.8 slide projector lens. My copy is labeled OKP-1-100-1, but later copies are labeled 35KP-1.8/100. The optics are the same, with a 6-lens-in-4-group formula.

I took it to my favorite place to try it out on Saturday.



With a register distance of 52mm, it can be adapted to any DSLR and still keep infinity focus. Of course it covers full frame, too. Rendering is actually much more even across the frame than the Helios lenses it's based on, with no noticeable swirl.



My setup is M42 adapter -> M42x1-M65x1 step-up ring -> M65 helicoid -> M65-Ø62.5 ring clamp. Just over 1kg total weight, and very front-heavy.

[scratchpaddy]

I've been working on a little project for the past week and a half. The focusing helicoid I used for the 16KP 50/1.2 has a really steep pitch. I think this is the case for all helicoid adapters, since for their intended use (macro) a large movement of the lens makes only a small difference in focus distance. It wasn't so bad for the 100mm lens, but the 50 was really difficult to focus accurately.

I measured the pitch of the helicoid and got 20mm, meaning one full 360° turn moves the lens 20mm. I measured the pitch of a manual nifty-fifty I like (SMC Takumar 55/1.8) and got 10mm. I decided to make my own focusing mechanism for the next lens:



It's a Singer "SUPER-BRIGHT" 2 inch (52mm) f/1.4. Yes, Singer the sewing maching company. They diversified in the '60's, and began selling (among other things) 16mm projectors for classrooms. This lens is from a late-'70's Insta-Load 2110. The projectors were assembled in the U.S.A, but the lens was outsourced to Japan. I also found identical lenses branded Bell & Howell for sale. Lots of them on eBay for $20 to $30.

I got to work on the computer...



Activated the portal between computer and reality...



Of course I'm over-simplifying, it took several iterations before I got the tolerances and function right, but it all turned out pretty well, eventually.



I made the threads on the back M42. I bought a "thin" M42 E-mount adapter, which omits the 27mm extension required to make a normal M42 lens work on E-mount. I have no idea why these exist, but it's perfect for this lens, which needs to sit 8.5mm (!) from the sensor for infinity focus.



The threads on the front of the lens are M54x1, of course not any standard filter thread. I was going to make an adapter to a standard M49x0.75, but just printed an entire hood instead.

I don't know how the lens will do when I take it out into the real world this weekend. It could be (probably will be) hot garbage, but I'm having fun making stuff.

[Jean Poitiers]

I've been working on a little project for the past week and a half.

...

I don't know how the lens will do when I take it out into the real world this weekend. It could be (probably will be) hot garbage, but I'm having fun making stuff.

Hi!

That's excellent! Looking forward to more results.

I have been toying with the idea of getting a 3D printer ... very tempting!

Cheers, J

[scratchpaddy]

Jean, I'm glad to see you're still around! I'm so glad you had the inspiration to start this thread all those years ago. I hope you don't mind me spamming it with dog pictures.

3d printers are kind of a pain. I got mine years ago to learn the process. Mine is a cheap kit you have to build yourself, so when it doesn't work, I know how to fix it. I honestly haven't used it much... more a failure of imagination than anything. These projector lenses are a great reason to get the printer going again.

The lens is actually kind of good. It's better than the 16kp-50 in a lot of technical ways: no massive spherical aberration, more accurate colors, and subjects can be placed almost at the edge of the image circle and still look OK. Especially my dog, she always looks OK. As a side note, I don't think the people here even realize how beautiful the morning light is. It takes my breath away sometimes, but they don't seem to notice it?



That said, I still like the 16kp-50 better overall. Its pictures are more pleasing to me, and one does not use a 16mm movie projector lens on a camera for technical excellence. The lack of spherical aberration is actually not a good thing when you factor in post-processing. Correcting it involves stretching the (dark, unwanted) corners away from the center, leaving you with more usable framing space. With no distortion to correct, you can't do that with this lens without making the picture look weird.



The focusing mechanism works pretty well, though.

[ohjajohh]

Today I bought a Colorplan 90mm f2.5 in mint condition. Now I only need to find a way to adapt it to my Sony A7iii

[Jean Poitiers]

Jean, I'm glad to see you're still around! I'm so glad you had the inspiration to start this thread all those years ago. I hope you don't mind me spamming it with dog pictures.

Hi there ! Thanks for your images ... and please share more !

PS - I'm a dog person ... mine is pushing 18+ years old now.

[Jean Poitiers]

Today I bought a Colorplan 90mm f2.5 in mint condition. Now I only need to find a way to adapt it to my Sony A7iii

Hi and hope to see some images soon.

Feel free to PM me if you have a question or two ...

Cheers, J

[scratchpaddy]

Today I bought a Colorplan 90mm f2.5 in mint condition. Now I only need to find a way to adapt it to my Sony A7iii

Looking forward to your results when you figure it out! I'd love to get one of those someday, but I'm not ready yet. On the one hand, they're cheap for a Leitz, but on the other, the normal asking prices seem pretty steep for a lens lacking a diaphragm, focus mechanism, or the means to attach to a camera.

I'm still on my 16mm film lens kick. I love these things. I found another for $25. I have many, many lenses, but this is my first American lens! It's a Simpson Optical Manufacturing Co, a.k.a. SOMCO 3in f/2 (3 inches is 75mm). I'm guessing it's from the mid-'60's. It strongly resembles a small flashlight.



I couldn't really find any info on the company or its lenses, so I did some original research here. I was hoping it would be a triplet, but it's not. It's a pair of cemented doublets, one at each end, basically the Petzval formula, 180 years old and counting.



It's very light, despite the brass construction, since it's so small and mostly empty. The back of the lens sits 15mm from the sensor for infinity focus. The rear element is recessed another 11mm deep in the lens tube, a total of 26mm from the sensor. I designed and 3d printed a one-piece adapter with an internal spiral to match the spiral groove on the body of the lens for focusing. The pitch of that spiral is only 1/8", or just over 3mm. That makes for very precise, but very slow, focusing. The image circle is not as big as I'd hoped, but no smaller than I had any right to expect on a lens designed for frames less than a third the size of my camera's sensor. This is uncropped on 35mm sensor.



I may have been hoping for triplet bubbles when I bought it, but the Petzval swirl I wound up with is fine with me. I'm a big swirly fan.



I love the colors it gives, rich and robust, and a joy to work with in post. The end results here may not look all that different from others I post, but the raw files this lens gives me are really pleasant no matter which way I pushed them. In comparison, the Soviet 16kp-1.2/50's colors are fun but inaccurate and sometimes bizarre, while the Singer is vaguely cold and unpleasant, and I struggled to get results I liked.



I blame the chrome plating extending all the way to the bottom edge of the lens for this big gold ring which appeared in backlit situations.



I'll be keeping this lens around for sure. If you can find one, I highly recommend it for users of APS-C or Micro-4/3 mirrorless cameras.