Mystery B&W FSU filters

[Armoured]

I have a set of the classic B&W photography filters (four colours), and they are even in a case with the KMZ / Krasnogorsk logo - but I can't for the life of me find what lens they were for, nor with what piece of equipment I got them (I've had various FSU photography gear, but almost all of it is rangefinder - Kiev / FED / Zorki.

So here's the thing: they're marked M26,5 X 0.5. they're tiny. I get the basics on what that means (diameter/thread), but again - cannot figure out what piece of equipment this could be for. I've checked all the lenses in my possession, and one or two that I sold recently (eg a Jupiter 12 in Kiev mount). So far, can't think of what it could be for.

Anyone know?

Last idea, could these be for an eyepiece on something?

 

[JeffS7444]

I have a set of the classic B&W photography filters (four colours), and they are even in a case with the KMZ / Krasnogorsk logo - but I can't for the life of me find what lens they were for, nor with what piece of equipment I got them (I've had various FSU photography gear, but almost all of it is rangefinder - Kiev / FED / Zorki.

So here's the thing: they're marked M26,5 X 0.5. they're tiny. I get the basics on what that means (diameter/thread), but again - cannot figure out what piece of equipment this could be for. I've checked all the lenses in my possession, and one or two that I sold recently (eg a Jupiter 12 in Kiev mount). So far, can't think of what it could be for.

Anyone know?

Last idea, could these be for an eyepiece on something?

Zenitar 16/2.8 fisheye:
Zenitar 16mm f/2.8 lens

 

[Dralowid]

Most FSU movie cameras (and they made an awful lot) were supplied with full set of accessories including sets of filters.

 

[Armoured]

Zenitar 16/2.8 fisheye:
Zenitar 16mm f/2.8 lens

Thank you! That explains it. I did indeed have one of these for a while, since passed on to someone else.

 

[Armoured]

I should have said - if anyone has this fisheye and needs the filters, I'd be happy to share with a member here for covering the cost of postage (from Ontario).