Turning a Leitz Epis Projector lens into a "Universal Epis" -apologies to Voigtländer

[Steven Tribe]

This another of my hairbrained schemes!

Both the Voigtländer Heliar and the large F.4 Epis projector series from Leitz have the first triplet design from Cooke (T,T & H). The central -ve lens is quite close to the rear lens in both products. The Heliar differs in that the front and rear lens are cemented doublets, rather than the simple meniscus lens of the "Epis". However, this was considered good enough for Cooke!

The Heliar Universal has the same basic design as the Heliar, but the central lens can be moved forward separately to achieve increasing degrees of "softness".

My thought was to modify the mounting of the Epis so that the focussing device (angled slot) would just move a shortened barrel, with the rather complicated central central lens mount, forward. The front and rear "cells" could be mounted to the sleeve to maintain their original positions.

Most "Epises" have a full length sleeve. A nice clean example can be seen currently, with better than average photos, at E**y 320880872634.
I do not know the seller - pure co-incidence! This is exactly the same Epis (F.4 and 400mm) that I have cut up.

This is basically a hacksaw job on the barrel. First cut off the rear cell complete with a section of barrel, Then do the same with the front cell.
After this, remove enough of the largest piece of the barrel containing the -ve lens to allow it to come right behind the front lens when the focussing slider is moved. The front and rear cells in a section of the cut barrel can be mounted using grub screws. Access for lens cleaning must be kept. The sliding shorter barrel does allow some light to enter from the side but doesn't influence focussing and a piece of dark cloth can be held over the lens. The system certainly works, although I think some kind of liner is nesessary to smoothen up the movement - shorter barrel means more "yawing". A very different image appears as the middle lens shoots forward. I will post some paper images and compare with the real thing as soon as I can. And using front stops as well.

The reason for doing this is because I had an Epis lying around and I know there are others that have one (also unloved and unused) as well (see previous Epis posts) and this might be a good and economical way of approaching the effect achieved in the real article. And at very different price. One good thing is the Epis flange is an integral part of the barrel so they are never lost.

[Michael E]

Have you completed your conversion? Can you show any images that you have taken with it?

Michael

[Steven Tribe]

Conversion is completed. The mounting is temporary at present - see photo.
Ground glass confirms " something happens". I'll post images - comparing with the real Universal - when I have had an opportunity.

[Ramiro Elena]

Yes, images please!

[imagedowser]

I have one of these... can't wait to see pics... Bill

[Steven Tribe]

Should be this weekend I can register some images.
Made a suitable lens boards for the real Universal now - comparison test.

The e**y Epis I mentioned, sold for what must be a record - 305USD. Pure coincidence!

[imagedowser]

Steven, Looking for a reason (pics) to "have at" this lens.... hacksaw at the ready.... If poss. a couple of progress shots if you took them so I'm less likely to screw it up or a shot or two of the lens after surgery. Thanks, Bill

[snarkfarts]

Dying to see pics!

[Steven Tribe]

I'll do a retrospective re-enactment of the operation - I still have the section I cut out! This is not for the very nervous!
Will post the photos on Saturday. And the paper prints on Sunday.

[Cor]

FYI

I have almost the same lens only labelled Vöigtlander, not with that hinged flap but with a nice black velvet lined leather lens cap. Anyway I could put to good use as a portrait lens for Wet plate work, it ain't a Petzval but has a nice signature at a fraction of the costs of a Petzval (obviously you shoot at f4)

Best,

Cor

[Math]

From what I've found even moving the front element in a triplet has a lot of effect on the 'glow' and softness of the lens. By using an older cheap triplet from a 6x9 folder, which generally have front-cell focusing, I could use the standard rails to focus and use the front-cell focusing to adjust the softness of the lens. By removing the pin that stops it from 'focusing' closer then 1m I could get some really nice results (Albeit not 4x5 covering results).

[Steven Tribe]

I hope this photos illustrate the operation.
Remember that the barrel is exactly the same length as the sleeve.
The hacksaw cuts are as near to the glass/glass mounting as possible - plus about 3mm!
The cell mounts for the front and rear are just thin walled threaded rings (the usual cheap projector system).
The mount for the central -ve lens is far more substantial and gives good rigidity to the barrel part which remains moveable.
So there are 3 hacksaw cuts - and none of them has to be perfect.
The cut out section is not shown in the photo so the gap is the amount that the central central can move forward. The original distance between the front and rear lens will be the same but the middle lens will move 1 hacksaw's cut thickness nearer the rear lens in the "sharp" position.
I originally thought that it would be great to have a waterhouse slot at this position and to use stops to reestablish the correct distance, but as you can see, this is exactly where the sleeve/flange system is.

[imagedowser]

Steven, Any prints yet? Bill

[Steven Tribe]

Difficult to balance grandchildren/children/birthdays/spring clearout/darkroom.
There are images in the filmholders (18x24) of flowering Fritillaria meleagris!

[cyberjunkie]

From what I've found even moving the front element in a triplet has a lot of effect on the 'glow' and softness of the lens. By using an older cheap triplet from a 6x9 folder, which generally have front-cell focusing, I could use the standard rails to focus and use the front-cell focusing to adjust the softness of the lens.


I think you have a Schneider Radionar. Do you?
They are in good shutter, have front lens focusing, and removing the screw you can freely turn the front element as much as you like... until it falls down! :)
AFAIK there should be some Radionar with enough FL to cover a 4x5" negative.
I own a 105mm one, which is good for 120 backs, but there is a 135mm which should cover 4x5", as the Vademecum (just checked) reports a 60 degrees coverage.
From the Vademecum i also learned a couple of things which were unkown to me:
1) There is a 120mm in between the 105mm and the 135mm (it should cover, for close subjects)
2) There were f/6.3 Radionars up to 500mm, though i doubt that they had front lens focusing :)

BTW, speaking of triplets and softness, i found that other lenses of the same design have that soft-ish signature, if used wide open. And not just the original TTH Cooke triplet.
Steinheil Cassars are an example, and also Meyer Trioplans (not just the expensive soft-focus or portrait versions, also the standard version with f/3.5 or f/4.5 aperture, which i am very happy to own).


Steven, i'd call it Epis Portrait, instead of Universal Epis :D IIRC, it's working exactly as the Cooke Portrait Series IIE i have at home!


have fun

CJ

[imagedowser]

Steven, Is it time yet? I can't hold it any longer. Need to see...

[Steven Tribe]

I have taken the shots - but fearing the darkroom after 3 fiascos, I have have lots of excuses! I also need a trip into Copenhagen to pick up fresh developer and fixer.
Since I last wrote, I have had a coated Cooke IIe to service (owned by someone else in the family, unfortunately!) and can assure you that it is the front lens that shots forward - not the central -ve lens as in the Universal.

[SteveR]

Glad I just happened to stumble across your thread, I've got the same lens (in black, but I might have to see if there's brass hiding under there!) and have been drawing up plans to build a camera around it. A forum member gave me an 8x10 pinhole as a base for the project, so I'm heading for a semi-dedicated 8x10 portrait camera. I've done quick & dirty tests with the lens in the window with curtains drawn around it and can get very nice looking 11x14 coverage, even nicer with an f11 aperture disc in the front. I'll be very interested to see what sort of coverage you get out of your lens in real-world application.

[Steven Tribe]

I can give you coverage later to-day (the development is still in limbo!) as I can mount it on a 30x40cm camera now!

[SteveR]

That'd be a nice size/aspect ratio to work in... I'll be happy with getting this 8x10 up and shooting for now, but who knows where it'll end up ;)

I just Popped out to the shed and attacked the flip lid of my lens with some steel wool, certainly looks brassy under there to me, but won't reveal itself easily. I guess I'll have to decide whether to keep it black, or spend the elbow grease and get that classic look...?

[Steven Tribe]

These were definitely sold with the black finish - fashion changes during time. Steel wool is, perhaps, not a good idea.
It illuminates 30x40cm (12x16") fully open.

[Alessandro]

Hi Steven,

Very interesting and simple modification. I just purchased a Epidiascoop in mint condition with the f3.6/400mm lens.
I will use the lens for my new build 310mm/310mm wet plate field camera (by Donchev camera's)
I was wondering if you have been posting any photo's that you have shot with the Epis? Can you share some? :)


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[Steven Tribe]

Thanks for reminding me! I should have some time in September and will post results in this thread.

[pierre506]

138955
Just found a F3.6 version, too.

[Jody_S]

I have an older 12" f4 version, it darkens the corners considerably at infinity on 8x10. I read this thread in '12 and resolved to attempt the modification myself when I got a new lathe. The new lathe is now in my garage, waiting for me to have the time to swap out the motor for one that will run on single phase. I suppose I could take a hacksaw to it, but I would like to keep it neat.

[Tony Lovell]

Steve, In your first post, at the end you mentioned using front stops. Can you tell me how well this worked please.
I was considering cutting an Epis to introduce a stop, but if it works well on the front it would same me the hassle.

[Steven Tribe]

It was difficult enough to convert the triplet so that the central lens would move forward - so adding a Waterhouse slot between the central lens and the rear lens was a step too far!

Mounting a stop system in front of the front lens was common until the WHS innovation of 1857. A few makers had introduced central stops before then, using split barrels or an enlongated front cells. I have used the front system on all my landscape menicus lenses, even a Plasticca as well as some (genuine!) 40's and early 50's unmodified Petzvals.