Mystery Lens vs EL-Nikkor 80/5.6 [metal]

[JCDowdy]

Isco-Gottingen Westar 80mm f/2.8?

[SteveCampbell]

Isco-Gottingen Westar 80mm f/2.8?

 

At first when I saw the brand I thought you were close, but alas, no

[rfcurry]

Perhaps a Schneider Componon-s 80/4.0 enlarger lens. That would be a suitable shoot-out, enlarger to enlarger. 6 elements in 4 groups isn't too bad.

 

edit: or the Schneider Componon 80mm f5.6, an older and less expensive enlarger lens.

[Andrea B.]

Meyer-Optik Diaplan 80mm f/2.8 ????

That is a projector lens!

 

But that is a fixed ap lens, isn't it? And a triplet with the weird bokeh which I do not see in the sample image.

[SteveCampbell]

Meyer-Optik Diaplan 80mm f/2.8 ????

That is a projector lens!

 

But that is a fixed ap lens, isn't it? And a triplet with the weird bokeh which I do not see in the sample image.

 

Very very very close!

 

Enough so that I'm happy giving away the answer - a Pentacon 80mm f2.8 projector lens! This lens is also a triplet, and of course not coated to reduce UV (it's meant for projection, not outdoor use after all!)

 

I reduced excess tubing with a hacksaw to allow infinity focus (sincere apologies, vintage preservation purists), and adapted it to a m52 helicoid. You can add an aperture with a Waterhouse slot if you really want, but I'll be using it predominantly for portraits anyway. It may be possible to adapt the lens by removing it from it's plastic housing first, but I preferred the simplicity of using a 52.5mm to m52 adapter

 

The big curiosity is that this performance appears quite consistent across many different projector lenses, including the Russian Triplet 78mm f2.8, as well as some longer projection lenses, to some degree. They're all quite amenable to dSLR adaptation.

 

The bubble bokeh needs some rather specific conditions, however the glowing effect that seems to reduce resolution may be a manifestation of these types of optics.

 

Note that a great number of projector lenses are uncoated triplets - perfect for UV, and generally large-aperture, for usable shutter-speeds. Curious to see other peoples' results!

 

Note: I can include details of my adaptation later if people are curious

[Andrea B.]

I must confess: I was looking around the web for info about Meyer-Optik* and

stumbled across that Diaplan 80/2.8 by pure accident.

Some nice photos made with it were shown.

 

Now about that hacksaw....are you saying that you sawed off the mount end of your Pentacon 80/2.8?

I would be curious to know how how much tubing you needed to remove.

 

Uncoated triplets are certainly the thing to look for, so Steve, you may have started a new lens search craze!

 

*I have a Meyer-Optik 35/4.5 Primagon.

[SteveCampbell]

I must confess: I was looking around the web for info about Meyer-Optik* and

stumbled across that Diaplan 80/2.8 by pure accident.

Some nice photos made with it were shown.

 

Now about that hacksaw....are you saying that you sawed off the mount end of your Pentacon 80/2.8?

I would be curious to know how how much tubing you needed to remove.

 

Uncoated triplets are certainly the thing to look for, so Steve, you may have started a new lens search craze!

 

*I have a Meyer-Optik 35/4.5 Primagon.

 

Ah yes, I have a diaplan 2.8/100 on the way. Apparently the exact same optics as the trioplan, but astronomically cheaper, of course.

 

I removed as much spiraled plastic tubing as possible without threatening the internally protruding glass element. The helicoid was a M52 17-31mm, which I could mount the lens to with a superglued 52mm to 46mm step down (if I recall correctly), and a step-up to 46mm (?) to 52mm, tightly secured inside the front with friction alone. I can check the diameters when I get home.

 

Hopefully I've started a craze - there is an almost inexhaustable supply of those projection triplets out there, so I can imagine price-gouging will be ineffective. Perhaps it'll also work to bring some of the already price-gouged lenses back to earth.

 

CORRECTIONS: 52->43mm and 43->52mm, and 36-90mm helicoid. Sorry!

[dabateman]

Well not at all what I was expecting. The first hit for me in Google was this:

 

No hacking required, just compression fitting. On MF lenses someone crazy glued into a helicoid. Apparently there is a long version and a short version. Also comments on a diplan 100mm f2.8.

Interesting, never thought to go that route, but faster aperture would be nice.

[Andrea B.]

Would there be any potential problems with veiling flare because you cannot stop down a fixed aperture projector lens ?

 

Is the distance between the film being projected and the end of the lens the equivalent of flange focal distance for a camera lens? Is there a name for this distance?

 

I think I'll go wander around Ebay to see what's available.

[SteveCampbell]

Well not at all what I was expecting. The first hit for me in Google was this:

 

No hacking required, just compression fitting. On MF lenses someone crazy glued into a helicoid. Apparently there is a long version and a short version. Also comments on a diplan 100mm f2.8.

Interesting, never thought to go that route, but faster aperture would be nice.

 

My issue was the lack of infinity focus with direct adaptation. Hacking off the end and fitting it into the helicoid (rather than in front of it) solved the issue for me. Of course an extension tube doesn't allow focus, so there's that issue too ...

 

I think a lot of people have used to lens to pursue bubble bokeh macros, where infinity focus isn't required

[SteveCampbell]

Would there be any potential problems with veiling flare because you cannot stop down a fixed aperture projector lens ?

 

Is the distance between the film being projected and the end of the lens the equivalent of flange focal distance for a camera lens? Is there a name for this distance?

 

I think I'll go wander around Ebay to see what's available.

 

Anecdotally I haven't had any problem with veiling flare, but I also have a 58mm takumar lens hood that I use to keep flare out. I've been quite surprised by the contrast I've managed to get however.

 

I'm not sure if the term "flange distance" is technically correct, but it makes sense to me in practical terms as the implications are the same

[dabateman]

@Andrea,

I think you mean flange focal distance.

https://en.m.wikipedia.org/wiki/Flange_focal_distance

 

Would still apply here as its from the back of the len. Steve is creating the lens mount to what ever he wants.

 

@Steve,

What was the distance you needed to get infinity focus?

[SteveCampbell]

@Andrea,

I think you mean flange focal distance.

https://en.m.wikipedia.org/wiki/Flange_focal_distance

 

Would still apply here as its from the back of the len. Steve is creating the lens mount to what ever he wants.

 

@Steve,

What was the distance you needed to get infinity focus?

 

I can't recall off the top of my head, but simply recessing the lens into the helicoid wasn't sufficient. I would imagine on a mirrorless camera with a thin mount it wouldn't be a problem.

[SteveCampbell]

Correction from what I said earlier - it's a 52mm to 43mm step-down, followed by 43mm to 52mm step-up on a 36-90mm helicoid (the 17-31mm is a different helicoid that I'm adapting for another rather interesting project...)

 

Reducing the lens to a total lens length of 5.5cm should be enough for infinity focus on a canon body with a M52 36-90mm helicoid and M52 -> Canon EF adapter.

[Andrea B.]

So, we will call it "flange focal distance" even if, technically-speaking, projector lenses do not have that. :D

I like to try to list FFDs in the Lens Sticky to give folks a guide to what kind of extension or helicoid they might need or to know which camera body would work best with an old lens discovered on the 'Bay.

 

I just checked and we have no projector lens listings in the Lens Sticky -- well, as far as I can determine. There might be one there which I don't recognize as such.

[SteveCampbell]

So, we will call it "flange focal distance" even if, technically-speaking, projector lenses do not have that. :D

I like to try to list FFDs in the Lens Sticky to give folks a guide to what kind of extension or helicoid they might need or to know which camera body would work best with an old lens discovered on the 'Bay.

 

I just checked and we have no projector lens listings in the Lens Sticky -- well, as far as I can determine. There might be one there which I don't recognize as such.

 

Yes, I haven't heard of anyone trying a projector lens for UV other than myself. Hopefully there's enough interest that we can populate the sticky with some new projection additions. After a very brief test, the triplet 78/2.8 looks similar in transmittance but is perhaps a little sharper. The triar-1 3.5/150 projection lens also looks usable in UV but not to the same performance as the 2.8/80 - lower contrast, slightly lower transmittance.