Adapting Lomos to PL Mount for Arri Alexa

[M Joel W]

I recently acquired about 15 OCT18 Lomo primes, and two Lomo anamorphic (well, one 50mm and one 75mm base with one shared front) lenses.

I'm hoping to buy an Alexa next year and I would like to use these lenses with it. Some focus rings are stiff, but I'm considering cherry picking five primes and servicing them and then using an adapter such as Raf's or the C7 adapter.

However, I have read that Raf's adapter does not work with Alexa XT and the C7 adapter does not work with PL mounts less deep than 19mm? I'm looking at 4:3 Alexa Plus but am considering an XT if prices bottom out next year.

My 18mm is also shattered, which seems to be common. I'm looking into getting a new optical block for it, but also looking into getting a 22mm f2, which my set is missing. I can only find this lens so far in OCT19 (though I know it is available in both mounts). Would buying it in OCT19 be a problem? I could just use two adapters... 

With focus gears will these lenses be useable? This would be for a personal set, I would rent for larger projects. Thanks.

Also, do these lenses cover 3.2k? Some Arri standard primes I have tried do not.

For such strange lenses, what matte box and ND filters would work?

Thanks!

Edited July 6, 2020 by M Joel W

[Aapo Lettinen]

Everyone including the adapter makers and our local rental houses say that the oct18 ones don't work with the Alexas or Amiras. Have not tested by myself but I have understood that the problem is the actual oct18 mount touching the filter stack holder or other part inside the alexa pl mount. So it is mount dependent I have understood. I believe there is some oct19 ones which can work when adapted and some of the zooms could be adapted too. 

The oct18 are very good lenses with nice look but s35 is at the very edge of their capability on wider than 50 and the 35mm may vignette a little whereas on the 28/2 you will see uncorrected retrofocus distortion on the edges which looks pretty weird. 50mm upwards tends to cover apsH or full frame. I remember the 50 maybe barely covers full frame. At least it is close.

If having a good adapter they can be focused reasonably well but you need to individually pair the adapter and the lens to get best functionality because there is slight differences in the tolerances of the adapter locks and wear of the mounts. Try couple of similar adapters to find the best working pairs.

On another thread you said you use eva1 at the moment. These lenses would be great with it if using pl mount (if they clear the mount. They should).

[Kyryll Sobolev]

joel, if you can tell me the make of each lens, i can tell you what frame they were designed to cover. on the lens body it should say something like ОКС1-50-4

lomo lenses do not have 0,8 pitch focus/iris gears, so you'd have to modify that

matte box for earlier lomos needs to be a rod-based one. lens fronts usually rotate, so cannot use clip-on mb. 

Edited July 6, 2020 by Kyryll Sobolev

[M Joel W]

Thanks, everyone. It seems they might work with an adapter in the older Alexas, but not the newer ones with the built in ND systems.

They do clear the EVA1 mount, barely. I tried one with a "dumb adapter" to EF mount and it has a nice image and good performance.

[victor huey]

Hi, Yah I have a similar quest. I recently had a oct19 mount made by Steve Morton, from a left over last batch of Oct.19 mounts to Classic Alexa's. C7 offers Oct.19 mounts for Alexa mini and Amira. I have a full sets of Oct.19 superspeed  and standard lens. The cost to convert to PL @$500 each, but with the Russian/Ukraine war, has made it a moot point. I too am waiting for the mini to come down, but Amira prices are dropping, so I can wait.In the mean time prices of Classic Alexa's are dropping below 6k, so when they get below 5k, maybe I will bite,lol. Good luck on the Oct.18 mounts, if you had the dough I would just rehouse them, Moscow workshop is working on new design, and GL optics in china can do rehouse conversions, @$3k each. Big decisions, but these are the options at the moment.

 

Victor

 

[M Joel W]

Thanks, Victor. Lucky you – the super speeds are legendary.

I think the OCT-19 mounts have more functional helicals than the OCT-18 do. The OCT-18 don't have helicals and the lens rotates in the mount more like an Arri Standard mount Cooke Speed Panchro (the Arri Standard Mount Mk1 standard speeds have their own helicals, I think the Cookes rotate in the mount and are thus more work to rehouse)....

Anyway, I ended up with a Raf Camera adapter and a Leitax PL mount (that can accept deeper PL mount lenses than the stock Arri mount) for my Alexa Plus. Right now I don't really shoot professionally much so I'm sort of just holding onto all this stuff because if I sold it I couldn't afford to buy it again! 

But I only own the standard speeds (two sets: one old, one from the 80s) and a 50mm/75mm anamorphic from the 60s. I haven't even tested this rig all together, but piecemeal it seems to work.

In your case, and I could be wrong, I'd just get an OCT-19 mount for your Alexa Mini when you get it – or convert the lenses each to PL, which should be easier than OCT-18. I could be wrong.

[victor huey]

Well I am gonna find out soon, as I got my hands on an Alexa XTplus, and will swap mounts with the Steve Morton OCT.19 mount, will let you know how it goes!

[victor huey]

here is a picture of Steve Morton's Oct.19 mount

[David Hessel]

From recent experience I can confirm that the Oct18 to PL adapters, the one with the pin for primes, does not work with the Arri Alexa Plus, I tried to use some on the 4:3 version and the adapter contacts an inner flange in the stock mount that doesn't allow the lens to fully seat.