LOMO OKC1-18-1 f2.8 18mm remounted for Sony NEX

iangreenhalgh1 · Expire: 2014-01-07

Hi folks

A while back I picked up the optical block of a LOMO 2.8/18 movie lens. These OKC lenses were professional lenses for 35mm movie cameras such as the Konvas and are widely reported to match the equivalents by Cooke and Zeiss.

These are normally seen in any one of a number of cine mounts, most commonly OCT-18 and OCT-19, and adapters are available to NEX, M4/3 and EOS. However, mine has no mount so I had to get the thinking cap on and come up with a DIY solution.

I happened to have a broken Pentacon PB 1.8/50 in my box of bits so I dug it out, stripped it down to just the helicoid and stuck a NEX mount on the back (from a set of extension tubes) which happened to be the same diameter as the rear of the barrel and fit perfectly.

I then used a thick plastic lens cap with a hole cut in the centre to form the front part of the new mount. The LOMO optic block fitted perfectly so it turned out to be a pretty simple job. Smile

I painted the internals of the butchered lens with satin black car body paint, three layers, and I also painted the conical part of the optical block as it was very heavily scratched with a lot of the black anodisation worn away and looked a mess.

It mounts perfectly on the NEX now, sadly it would have been too complicated to try to fit some form of aperture control so I just set the aperture to the halfway closed position which should be around f8, I figure the dof of such a wide lens will be ample for most shots.

It's a big and unwieldy looking contraption but it does work, I'm rather happy with it. Very Happy

Th only issue is it focuses past infinity, but hey, the NEX has live view so it's really not a problem.

It's pouring with rain and really dark here today so proper testing will have to wait until mr sun rears his head again, but some test shots around my house look promising, it's definitely sharp enough and has very little distortion. I think I see a tiny bit of CA at the edges, but overall, I'd say this is pretty good for an 18mm lens made in 1961. Wink

Attila · Expire: 2025-11-18

IQ is excellent , looking is Laughing

thank you for sharing!

iangreenhalgh1 · Expire: 2014-01-07

Cheers Attila, the ludicrous look of the thing adds to it's appeal for me. Laughing

Here's some more samples, just hope we get some sunshine soon to really try this thing out. Sad

#1

#2

#3

#4

#5

#6

Lloydy · Expire: 2022-01-01

That looks as though it's worth making a proper mount for, those are very good for test pictures. There's a lot of potential in that lens.

Attila · Expire: 2025-11-18

iangreenhalgh1 · Expire: 2014-01-07

Cheers David. This mount is the best I can manage, it focuses from just past infinity down to about 1cm, that last one of the leaf was at about 8cm from the leaf. I can live with the fixed aperture as dof is ample yet not too small to not give some bokeh on close-ups. It's a shame I can't control the aperture though as it has really nice bokeh wide open on closeups. It will also take rear mounted filters if I can find the right size ones to fit inside the throat of the NEX bayonet on the back.

The mount I made is only held together with epoxy so one day when I have some spare cash I might get a skilled person to properly mount this thing. On ebay, this lens is a few hundred dollars with a mount and adapters to NEX are 100USD.

Pancolart · Expire: 2013-11-18

This looks darn good and cinematic. Nice adaptation, obviously worth every effort.

sichko · Joined: 20 Jun 2008 Posts: 2475 Location: South West UK

Nicely done Ian.

iangreenhalgh1 · Expire: 2014-01-07

Cheers guys, what really stands out for me is how rectilinear it is for such a wide lens.

I think this would be a great lens for shooting video, give a cinematic look like pancolart says.

I might have to try shooting some video with it, I've only tried the video on my NEX once.

aspen · Expire: 2014-02-20

Bravo Ian! *applause*

patrickh · Expire: 2011-11-18

Good stuff! Where's your Da's Rover?

patrickh

poilu · Expire: 2019-08-29

nice look, great adaptation and promising results !

iangreenhalgh1 · Expire: 2014-01-07

Cheers guys, I am relieved my DIY efforts worked out, I haven't tried any diy things for a long time as they are rarely worth it, but a 2.8/18 isn't exactly easy to find so I figured this one was worth a try.

The Rover is in the garage covered up with sheets atm, it's barely stopepd raining in two weeks here, everywhere is flooded, worst summer I can remember. Sad

I'll try some Rover shots with this lens when he has it out again, I did a series with my Tokina 3.5/17 that came out nice, I think ultrawides are good for shooting cars.

pich900 · Expire: 2012-12-27

Jesito · Expire: 2015-01-07

Impressive, both the implementation and the results!.
Congrats,

Jes.

iangreenhalgh1 · Expire: 2014-01-07

Thanks guys. Still raining here sadly so no nice series with this lens yet Sad

I have been searching for info and found a page with all the specs on this lens:

http://www.geocities.ws/kinor35/lenses/lenses-prime-wide/018-oks-1-18-1.htm

Focal length...........................18.12mm

Actual aperture.............................. 1:2,8

Angle of coverage(Lens angle ).......76'

Photographical resolving power....64/27 lines per mm

Transmittance factor.......................0.75

Light diameter of the front lens...........80,4 mm

Light diameter of the back lens...........14mm

Length of the lens.............................84 mm

Most diameter of the optical block....99mm

Landing thread of the optical block...M21x0.5

Size of the frame...............................16 x 22mm,

Weight.............................................0.41 kg,

I query one thing from those figures, it gives 76 degrees as the angle of coverage, that sounds too small to me??

The optical schema looks complex:

iangreenhalgh1 · Expire: 2014-01-07

Weather still not nice but I did shoot some more shots with this lens.

These two are at waist level, seeing how it works for candid street shooting:

#1

#2

This was just to test distortion and CA, looks great in both regards to me. Smile

#3

A couple inside the post office, see how it does indoors:

#4

#5

Here I was testing how the bokeh is with the fixed aperture:

#6

#7

#8

A few more random shots:

#9

#10

#11

#12

#13

skida · Posted: Wed Jun 27, 2012 7:05 pm Post subject:

Great results with that camera/lens combo, amazing really.

Attila · Expire: 2025-11-18

iangreenhalgh1 · Expire: 2014-01-07

Cheers, you know a lens is a good one if I can make it look good, I'm not one of these guys that can make a poor lens look good. Very Happy

Now I just need some sunshine to work with, the contrast of this lens is excellent in poor light which suggests excellent coating, but with that huge front element I want to see how flare resistant it is, but that need sunshine. A hood would have to be a DIY affair too as it doesn't have any threads.

iangreenhalgh1 · Expire: 2014-01-07

I found the original datasheets for this lens:

Alex H · Joined: 25 Dec 2011 Posts: 344

Sorry for resurrecting the old thread, but I just want to ask Ian one simple question:

Ian, did You ever try OKC1-10-1 2.8/10mm lens? I have searched for example pictures shot with this lens, and those few that I found are not very impressive...

iangreenhalgh1 · Expire: 2014-01-07

Isn't that a 16mm lens?

Alex H · Joined: 25 Dec 2011 Posts: 344

iangreenhalgh1 · Expire: 2014-01-07

I don't see any reason for it not to be upto the standard of the other OKC lenses.