Opalar GO-90 - Hydro Lens

Today this rare underwater lens from 1993 arrived to me here in San Francisco from Belarus! It was made by "Opal" which I understand may be an experimental division of LOMO.

I put it in the WIKI, and there you can see more photos of it.

Does anyone know what camera this would have been made for, or any other information about it?







Regards, Bill

Hello dear Bill
Carefully seeing pictures of your extraordinary Hydro-Opalar I noted the clear existence of divergent(negative) elements in the frontal and rear faces of the optics. That means that this type has great possibilities not to work in large back focus mounts like Zenit 3M. It seems these lenses were made for FEDs and Zorkis. Try to put in it a M39 Zenit and see through the finder. Can you see an image? In extreme close-up? Answer me I am curious
Regards LP

Luiz,

Why would this lens manual list an M42 adapter as part of the kit if it wasn't made for Zenit cameras?

Vlad

Luiz,
You are exactly correct! When I put it on a Zenit 3M it will not focus normally ... only in close-up, as you say. I discovered this after I wrote the WIKI entry but have not yet changed it. Very good observation from the photos.
I also now believe that it is for a rangefinder like FED or Zorki, or possibly Leningrad. Also maybe some possibility that it is for a non-Soviet camera as I have found some references on the internet about the Hydro- Russar being used with on live (television) cameras (a Panasonic camera) for detecting deep sea nodules, which I believe refers some type of undersea mining of minerals on the bottom of the ocean (but not sure of this).
I will try it on a later Zorki or Leningrad, using a ground glass and open back to see if it focuses properly on one of those cameras.
Vlad ... about M42 adaptor ... maybe also for this kind of television camera, but I am not familiar with the size of the mounts for these ... maybe Luiz is.


Regards, Bill

But isn't underwater focussing different from "air"? I really don't remember which way the focus differences, but something odd there was.

Best regards,
Juhani

Answer to Juhani, Vlad and Bill.
This lens probably will correctly focus on air with Zorki etc cameras giving normal wide angle covering (around 90є).
In another media like water the higher refraction index will offer a greater image and a consequent narrower angle. In loose words we can say that considering the same sinus length observed on air, a shorter distance will be needed from the lens nodule to the object in water media due the higher refraction index, and this distance is equal to the quocient berween air refraction index and water refraction index,
approximatedly .66. (or 60є) see diagram.
Regards
LP

Fascinating! Luiz, I bow to your expertise and I absolutely accept your analysis . And Bill I apologize, I was wrong in our direct communications when I said that it was most likely for Zenit, the M42 adapter had absolutely convinced me of that fact at the time.

Vlad

Nice illustration of the differences in the angles of coverage between air and water, Luiz. Thank you for those.

So Vlad (of course no apology necessary, and I had already thought the same thing) .. then the question then is ... what M-42 mount camera, as well as, what M-39 mount camera would this lens be for? The passport does seem to indicate that it will be for a 35mm camera.

I have thought maybe Leningrad since it's automatic function is useful for underwater photography ... but that may be wrong. Are there any M-42 rangefinders that will have the proper focal plane distance? Or, is it made for some non-Russian camera?

Regards, Bill

M42?
It delivers a research.
Regards LP

I've just received one, also from Belarus. Mine is 0693, so we now know that at least 6 of them were made. There was no passport with it, and it came in a Bakelite case that obviously wasn't made for it: someone has cut a foam disk and a spacer to keep the lens safe in the container. The foam looks pretty old, and it could even date back to the 90s. The lens looks exactly like the one pictured above (except, of course, for the serial number).

I've not had an opportunity to try it yet, but I'll put it on my trusty FED-2 tomorrow.

Here are a few comments from my experience of using the lens.

First off, although it fits the standard M39 mount it isn't a standard LTM rangefinder lens. Only objects very close to the lens are in focus. Am I wrong to conclude that to correct this the lens should be mounted nearer to the plane of the film? But this won't be possible as there is a ring around the lens just below the aperture ring against which the body of the camera sits when screwed in.

As you'd expect with a lens as wide as 20mm here's a fair bit of barrel distortion, but correcting that is not a problem with software like PTLens,

The lens appears to render colours really quite nicely in a variety of lighting conditions.

That's about as much as I can say. Does anyone have any ideas what camera this might have been designed for? It looks like it could produce very nice images if mounted at the correct distance from the film plane. Would it help to know what camera the Hydrorussar was designed for, aas this is supposed to be an "improved" version? I will happily post some of the images I have from it if anyone is interested.

Carl, I don't know if it's going to be possible, but from what I'm reading in this thread and if I'm understanding this correctly, the lens would only focus correctly underwater? It's not easy to test unless you have a KRAB enclosure..

Vlad.

Vlad

Thanks for the response.

I may not be able to get much joy with a RF but a bit of experimentation makes me think it will work with a micro 4/3 camera. I think I may be able to modify a Photodiox adapter - if I can get hold of some 0.5mm or 1mm thick circular shims that would be suitable for an M39 lens.

I've constructed the Micro 4/3 adapter for the Opalar. Here's the first picture using it, taken wide open at f3.5:



As you can see the image has some faults: resolution falls off pretty noticeably towards the edge, there's obvious chromatic aberration and there's distortion. Nonetheless, it seems to portray colours pretty well even though the really light was as poor as it looks - after all, this was London on a January afternoon. Things would probably look better stopped down and with the shims slightly adjusted, but I don't think the faults will completely go away.

The lens lacks a focussing ring, but (at least on this example) the barrel can be rotated slightly to move the elements away from the sensor. About 1/4 of a turn is all that is needed between sharpness at infinity and at 1 metre.

Of course this is misusing the lens: it was designed for underwater photography so none of these faults might be so obvious in that context. But it's a shame to have a lens and not use it.