[FS: OPTICS] 65/70mm ultrarare zoom: CKBK 70OPF5-1 40-240mm f/4.5-5.6 #740001

[Ilya O.]

FOR SALE ITEM and LOCATION
70OPF5-1 f/4.5-5.0 #740001 large format 65/70mm film zoom (52x23mm gate).
Unique pre-series prototype made in 1974 by CKBK (Central Design Bureau of Cinematography, St. Petersburg, USSR). A lens that appears for sale once in a lifetime.
Located in Moscow, Russia.

This is a kind of charity sale, guys. My goal is to give the income to the noble cameraman, a 3D & 70mm soviet film pioneer, and a very nice, active person. I take only service/test and client find fee. So you will pay him directly without any intermediates.

DESCRIPTION
The lens was recently serviced (service pics on request), so glass is clear and all rings despite the weight have light and smooth move. Front bellows-type leather cover was fully restored and dust-sealed.
The zoom is in fully working condition, internals are robust in design (all air-grade aluminum, focus/zoom system is based on stainless steel cam follower bearing and Teflon balls (Fluoropolymer/PFTE).
Lens gives nice warm pictures with no optical misalignment or visible flaws. I would say that from the optical bench tests (diffraction dot results) it shows very good performance for a 40-240mm large format zoom of the era. It is pretty sharp at center and has a smooth falloff towards the edge. The lens seems to be parfocal.

Note:
— there is some minor quirks like little scratches and paint chips here and there on the barrel. Check the lens gallery;
— there are some micro scratches on the coatings of some internal lenses;
— there is one 5mm in diameter circle of little dots on the coating behind the second glass; you can notice it here, exaggerated by hard light here: http://goo.gl/CgKJXd
No glass damage or something that degrade center performance, I tested that. These dots are the result of zoom group touching the focusing group in extreme zoom-out (more than 40mm) at infinity with the lens positioned frontside down. Now the lens was modified with spacers inside and ring move limiter outside so that scenario is now impossible;
— the mount is from Soviet hand-held 70mm cam, so you must adapt it to the contemporary ones like Arri XPL/Panavision PV65/some medium-format still mount. The original mount is easily detachable, there is plenty of metal surface and space to place any mount you want;
— minimum focus distance is 4 meters (13,12 feet). You can reach 2.5 m (8.2 feet) with front dioptric close focus lens (barrel has engravings for that distance). I don't have that lens;
— the lens weights 12.5kg (27.56 lbs).

IMAGES
Google gallery with overall condition, optical bench tests, chart 14K tests, all wide open: http://goo.gl/CGM4pc

Some pics:

TERMS
BANK WIRE ONLY. Buyer pays shipping and fees.
Item ships Worldwide.

PRICE
Is 20,000$

CONTACT
Via email moscow.optical.workshop[at]gmail.com

 

[Ilya O.]

up!

 

[Ilya O.]

bump

 

[Ilya O.]

Guys, big sensor are already at the doors!

It's smart to think about the lenses now. This zoom is superb.

 

[Ilya O.]

move up

 

[Ilya O.]

price drop, now asking 22,500 usd

 

[Ilya O.]

price drop, now for 20,000 usd

 

[Ilya O.]

bump

 

[Miroslav Gerbel]

PM me if stil aviable

 

[Ilya O.]

pm sent, no response

bumping up

 

[Cristina Kowalska]

Ilya, could You give more informations about:
1) on lens is f/4.5, but in Your description is f/4.5-5.6; from what focal lenght it is more than f/4.5 ?
2) it is f/4.5-5.6, but what are T-stops (and are they marked on the lens);
I think those are important Thank You !

 

[Ilya O.]

Hi Cristina.

For sure everything is important

The lens itself is f4.5 at any of zoom postition, optically speaking, that's why the papers say 4.5.

To increase the lens IQ throught the zooming range, a mechanical coupling of the zoom component and the iris is added so when you zoom in, the iris closes a bit, namely to something close to f5.6, lets say f5.3 (not to f5.6 as I conservatevely write in the descriprion). The ramping starts at about 125mm and gradually reaches ~f5.3 at 240mm.

To say more, if you hold and fix the iris ring slightly with the fingers the ramping starts only at 200mm and then you feel the ring definitely wants to close to f5.0 or a bit brighter like f4.9 at 240mm. So, if used like that, the ring says f-stop is 4.9 at the tele end.

So, does it ramp? Yes, but not as severe as one could expect, and not at the whole range.
To say more, i think it's possible to disable that coupling completely since it's a simple mechanical gear. But I doubt it's reasonable since the original Patent says there's a need for that.

Second, the red engraving on the iris ring shows f-stop number s (which is strange for a cine lens which always show T stops. I put this to the fact it's a prototype lens). If we look at the NIKFI test report table, it says T-stop is 5.2
Approaching from the other angle, the lens has 69% light transmission coefficient. That lets us calculate the T stop theoretically: one should divide the f-stop by the square root of transmission coefficient, so: T=4.5 / √69 which gives T-stop of 5.4

 

[Ilya O.]

bump it up

 

[Ilya O.]

Bump

 

[Ilya O.]

I say go up!

 

[Ilya O.]

Price reduced, now for 16 500usd!

 

[Roy Kurtluyan]

What mount is this Zoom? From the pictures, I couldn't tell the mount?

 

[Ilya O.]

Hi Roy, sorry for delay, for some reason new part notification does not work here:-(

The mount is from Soviet hand-held 70mm cam, so you should consider adapting it to the contemporary ones like Arri XPL/Panavision PV65/some medium-format still mount.
The original mount is easily detachable, and there is plenty of metal surface and space to place any mount you want.

 

[Ilya O.]

Bump

 

[Andy Smith]

nice zoom ! but why You do not do conversion by Your own ? this is better to get it with PL from You, than with this mount from You and than send it to re-housing company, than back, as it is very heavy and fragile lens. think about it my Friend