Watch out for Russian Made PL Mounts

Chris_Burket · November 3, 2006

I recently bought a PL mount Konvas 2m from a dealer in Russia. Upon receiving it, everything seemed fine. However when I took it to Slow Motion inc. to have it looked over, I found out the PL mount was faulty. It was poorly constructed and as a result, will not accept any of the newer high end lenses (Arri Ultra Primes, Master Primes, Cooke S4's). The mount does function and will accept Russian Elite Lenses, or very very old PL mount lenses of most brands.

So buyer beware of the Russian PL mounts, they may not work with all the new PL mount lenses.

Rafael Pankratau · November 3, 2006

So buyer beware of the Russian PL mounts, they may not work with all the new PL mount lenses.

Though I can't find a record about you in my archive (and thus believe that this wasn't my mount), I suppose that my mounts may have problems with newer PL lenses too. Such lenses are too expensive for us to have one for test purposes, unfortunately, so we are working with old lenses here.

But if there is someone who bought our mount and tried them with new lenses, I would like to hear if it works.

Thanks.

Olex Kalynychenko · November 3, 2006

I recently bought a PL mount Konvas 2m from a dealer in Russia. Upon receiving it, everything seemed fine. However when I took it to Slow Motion inc. to have it looked over, I found out the PL mount was faulty. It was poorly constructed and as a result, will not accept any of the newer high end lenses (Arri Ultra Primes, Master Primes, Cooke S4's). The mount does function and will accept Russian Elite Lenses, or very very old PL mount lenses of most brands.

So buyer beware of the Russian PL mounts, they may not work with all the new PL mount lenses.

I will answer on behalf of all russian camera technician

Not good story, but, we need study of this problem from all sides.

Konvas-2M camera , made at 1990, and modified on Arri PL lens mount a few years ago.

But, at time of modification on Arri Pl, the camera technician know not about Ultra Pirme and Cooke S4s lenses on future. He designed of lens mount for West lenses with Pl mount available at time of modification.

If the Arri and Cooke company showed all official drafts of lens mount with sizes, we can use this sizes for design of mounts and attachment and have not problem with compatibility of modern lenses.

But, Arri and Cooke not do this and we must take dimensions from original lenses. Arri company show, Arri lenses must be use with Arri cameras only.

Yes, of course, we can use other idea and buy original lens mount from Arri company and modify of Konvas camera.

But, This is original lens mount will have super high price, more price of camera.

But, the buyer wish pay small price.

You can check of price of any original screw or washer or part of Arri camera and compare with price of Pl mount for Konvas camera

Yes, this is a some risk of have a some problem with next generation of lenses on future, because, we know not, what new lenses Create of lens companies.

But, the similar problme can be with any old camera and modern lenses on future.

The user can rent of Arri studio camera and Ultra Prime lenses with work with Arri studio camera fine.

But, user wish use Ultra Prime lenses with Konvas.

I wish show a some my ideas from technical side.

I check of my old notes, check a some drafts of PL mount and other additional information.

The PL lens mount of Ultra Prime , Cooke and old generations of Carl Zeiss lenses have not difference.

This is flange focal distance 51.98 mm and diameter of mount 54.00 mm.

The modern lenses have electrical contacts for electronics.

The contacts not influence on connect modern lenses with old cameras with Arri PL.

Yes, If we told about Russian lenses with Arri PL lens mount and Carl Zeiss Pl mounted lenses I see a some differences on diameters. This is outside diameter of lens mount. Original Carl Zeiss lenses have PL mount with outside diameter of blades 68.6 mm, the some Russian lenses can have similar diameter with size 68.4 mm. You can see, the difference on 0.2 mm can be a some problem. From other side, the lens mount must have gap between outside diameter of blades and inside diameter of lens mount on 0.3..0.5 mm.

But, I think, the problem from the other side.

The modern lenses have electronics and additional electronic control inside of body.

But, the user wish have fast lenses and manufacturer must install big size glass inside of lens body too.

What must do manufacturer ? They must increase of diameter of lenses.

Ultra Prime lenses have more big diameter of rear side of lens, near lens mount.

That's why, The lever PL mount of Konvas, designed for previous generation of lenses can set on body of lens.

From other side, The modern lenses, Ultra Prime, Cooke have very short distance between fit ring of camera lens mount and rear parts of body of lens ( before of surface of lens mount ).

Possible, This is PL mount of Konvas camera design for more old lenses with more thick body of a fit ring of camera lens mount and Ultra Prime lens abut against of rear part of body on front surface of feet ring of lens mount of camera.

If you send me more pictures of lens mount of your camera, I can give you more information .

Possible, you will need modify of front surface of your lens mount and lever of camera mount.

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The everyone make a personal choice, to pay big money and have no any problem ( moot point) or pay small money and have a some risk.

Chris_Burket · November 4, 2006

Olex, you are correct in regard to why some of the lenses didn't fit. I will take some detailed photos and get some more information about the problem next week.

I don't blame the builder of the mount, or the person who sold me the kit which is why I won't even mention a name. It's simply a problem that the person constructing the mount could not have anticipated, but I thought people should be aware of it and now I can investigate all possible fixes.

After determining all possible fixes, I may or may not fix the mount. It does work with Elite Lenses which are really beautiful lenses so I will probably shoot with those for a while at least a while.

I don't want to give people the impression that the mount is totally faulty, because its not. It's simply a compatability problem with certain lenses due to the dimension of the lenses.

Michael Maier · November 21, 2006

Not sure I quite understand what's wrong. I mean a PL mount is a PL mount. What's different on the newer lenses? The lens flanges are thicker or what?

Phil Rhodes · November 21, 2006

Hi,

> I mean a PL mount is a PL mount

Clearly not so!

This situation is insane and helps nobody; I'd hate to discover that Cooke or Arri think they're helping anyone, including themselves, if they're actually refusing to release drawings.

Phil

Michael Maier · November 22, 2006

But what is it people are finding to be a problem with the newer Arris and Cookes? The flange thickness? Otherwise I can't see what wouldn't fit.

Olex Kalynychenko · November 23, 2006

But what is it people are finding to be a problem with the newer Arris and Cookes? The flange thickness? Otherwise I can't see what wouldn't fit.

The base parameters of Arri PL mount not changed. The diameter of hole , diameter of blades, the size of blades, the thickness of blades not changed.

They changed a minimum distance between rear parts of lens and front surface of blades.

They changed of maximum diameter of rear part of lens body.

That's why, if the draw ring of lens mount have big thickness and more big diameter ( for more high power clamping of lens with lens mount of body ), you can not set modern lenses with reinforced lens mount of camera.

Not worry too much, the technicians, who modify of Konvas cameras now have versions of Arri PL lens mount for

modern lenses and you can order this mounts.