The "what is this strange filter and what lenses does it fit?" thread

[Helge]

I can't be the only one who once in a while gets a box with various kinds of interesting stuff, and finds a stack of filters.
A few of them makes you wonder what system, purpose and thread type the filter is for.
Usually Google is useless for that kind of stuff.
I thought I'd make a general thread for this kind of question. Someone here is bound to know the answer at some point in time.
"What is it?" stuff other than filters is also welcome here, but usually other accessories are easier to google.

Let me open the ball with two filters I haven't been able to find a good use for, though they intrigue me for a couple of reasons.

One is a filter holder of some sort from B + W 46E. It fits a 46 filter thread as it says one the side. I have one similar in a larger thread too.
These seems to be some kind of step up ring with spring clamps instead of threads for the filter. They can't be meant for Series filters and they also don't seem ideal to just hold a regular threaded filter for easy snap on, snap off action.


The other is a holder from Omag. Still not a Series filter holder, since this takes completely naked filter glass.
It says Omag 46 Swiss on it and it has the complete opposite "problem" of the previous filter. IE, it has a push one "thread".
I have six of the glass discs for colour correction and black and white, so a complete set of regular non FX filters for just about any condition.
Trouble is, I have never been able to find a camera that fits the damn push on/in size (almost exactly 42mm on the inside). Usually this kind of push on filter (and Omag brand), is used for folders. But this is much too big for any folder lens I have ever come across.
I know this is kind of the reverse of the usual problem of finding a filter to fit the camera, but I'm curious, and it is some nice versatile filter glass that takes up very little space and are easy to mount.

 

[Kino]

If one can extrapolate from just the form/function/manufacturer, the Omag filters appear to be for a Leica Summaron 35mm f2.8 M lens.

Maybe the first is some sort of adapter for the same?

 

[Helge]

Yes, I have tried that. It appears google has changed it's mind since last time. There is indeed a hit on the Omag filter.
Does it fit anything else? I have vowed to myself never to get into Leica, neither Barnack or M. They are nice cameras of course, but are exceptionally overpriced for what they do (nothing that other brands don't). And the "fit, feel and finish" crowd can fuck right off! ;-P I just don't feel it.

The other B + W doesn't fit anything else, and certainly not the Omag holder.

 

[AgX]

Item #1 I assume to be an M46 filter-thread push-on adapter for a lens with plain, unthreaded front-ring.

 

[Helge]

Item #1 I assume to be an M46 filter-thread push-on adapter for a lens with plain, unthreaded front-ring.

Yes, that much is clear. But what lenses, other than Barnack rangefinder lenses (see above) has that front diameter?

 

[AgX]

I see. But you did not state the push-on size. Is it 46mm too? Furthermore there is some play anyway, as the wings can be bent a bit. It could be meant to upgrade some lower end lenses. Thus not rangefinder lenses.

Those two cut-outs likely are intended to enable to twist the front ring of a front-element-focusing triplet. So that one has not to rely on the friction between lens and adapter, but instead can grip the lens directly.
Those cut-outs even include the threading.

 

[glbeas]

Looks like the two parts fit together to hold the filter glass. Tried that?

 

[Helge]

Looks like the two parts fit together to hold the filter glass. Tried that?

No the Omag is just a standard Omag filter holder like for folders, just bigger. A front ring screws in and holds the glass, and the whole thing pushes on to the lens. But what lenses is exactly 42?

I see. But you did not state the push-on size. Is it 46mm too? Furthermore there is some play anyway, as the wings can be bent a bit. It could be meant to upgrade some lower end lenses. Thus not rangefinder lenses.

Those two cut-outs likely are intended to enable to twist the front ring of a front-element-focusing triplet. So that one has not to rely on the friction between lens and adapter, but instead can grip the lens directly.
Those cut-outs even include the threading.

Actually I did state the size of the Omag "(almost exactly 42mm on the inside)", if that's what you mean.

The B + W has a 46mm thread and a ca. 55mm push in spring loaded holder.
Actually I did just try a 55mm threaded filter in the holder. In fact it fits well If you flex the springs.
But it does some not so nice things to the thread of the filter though.
Even after at single insertion, the threads of the trial filter was scratched. I can only imagine what multiple insertions are going to do to the threads.
But maybe the filters in the 50s/60s had slightly different threads, and this is in fact the correct use?

 

[AgX]

Helge, you seemingly completely misunderstood what I wrote above on the use of the B&W thing. To me the part with the springs/wings is to hold that thing on the plain front of a lens barrel. The thread is to take a 46mm filter.

I write this in the assumption that the thing got a female thread. However, it just came to my mind that the designation 46E so far only was used on filters, and referring to their male thread.

Then assuming that thing got a male thread instead, the thing might be used to hold filter-glass discs, and the cut outs are intended to facilitate inserting and taking-out the discs.

 

[Arthurwg]

Yes, I have tried that. It appears google has changed it's mind since last time. There is indeed a hit on the Omag filter.
Does it fit anything else? I have vowed to myself never to get into Leica, neither Barnack or M. They are nice cameras of course, but are exceptionally overpriced for what they do (nothing that other brands don't). And the "fit, feel and finish" crowd can fuck right off! ;-P I just don't feel it.

The other B + W doesn't fit anything else, and certainly not the Omag holder.

Well, you should try a Leica before you say those things. There's a reason that so many great photographers made so many great pictures with a Leica.

 

[Helge]

Helge, you seemingly completely misunderstood what I wrote above on the use of the B&W thing. To me the part with the springs/wings is to hold that thing on the plain front of a lens barrel. The thread is to take a 46mm filter.

I write this in the assumption that the thing got a female thread. However, it just came to my mind that the designation 46E so far only was used on filters, and referring to their male thread.

Then assuming that thing got a male thread instead, the thing might be used to hold filter-glass discs, and the cut outs are intended to facilitate inserting and taking-out the discs.

Exactly! I should have provided images of both sides.

 

[AgX]

So, you too think it is a holder for filter-glass discs?

 

[Helge]

So, you too think it is a holder for filter-glass discs?

No, it might be a step up, quick fasten holder for regular 55mm threaded filters though.
Still not settled on whether it damages the threads though.

 

[Helge]

Well, you should try a Leica before you say those things. There's a reason that so many great photographers made so many great pictures with a Leica.

I have, and I really like them. I don’t think they are more special than other good cameras though.
Even if I might be convinced to get a Barnack body, the lenses are still insultingly expensive for what they are.

 

[Helge]

I have a bunch of these small packages of coloured and diffuser filters, all exactly the same.
They seem to be more prevalent than the flash they fit.
Obviously they are for a flash, but what brand and what model?

 

[Kino]

Probably some model of Metz strobe. Looks like the proper form factor...

 

[Helge]

My thought too. Metz usually branded their stuff clearly though.
They are not for any of the hammerhead ones, I can tell you as much.

 

[AgX]

The Metz ones for the type 45 have flanges at the short side and and the name stamped on the case.
However their shape and those fixing ridges make me guess they are for the on-camera flash series from Metz from the 70's (e.g. 34 BCT, 40 CT etc.)

 

[Helge]

Well it’s not meant for 34 BCT 1.
It does sort of fit (without clicking into place and standing proud about a cm), and the length is exactly covering the window. So perhaps it fits the other later models in the series.

 

[Kino]

I think you are probably right.

 

[AgX]

To my understanding the outer size of all these Metz 70's flashes are the same. I used the GNm40 of that series with such turning knob at the front in the 70s, but have never put different models aside. But even in case there should be a size difference, it would not apply to the reflector.
And there are no later models such filter could fit. And aside the protruding they seem to fit. Must be a dimension coincidence with a completely different flash.
Strange...

 

[Helge]

Anyone know about Omag Minar diopter/closeup filters?
They seem to be abundant and take up very little space in those nice little Omag bags.

I have trouble differentiating the filters though and there is very little on the web about them.

I have two, but one of them is lost in some box or bag right now though.
The Minar 33 and the 50 cover different closeup ranges.
But there is no way if knowing which one I have in my hand right now.
There is a small notch cut into the side. Perhaps a code?

Anyone know about these, or alternatively a way of determining the range without actually going through the trouble of shooting some frames, developing and scanning?
I mean I have the tables already.

 

[Ray Morgenweck]

OMG remember those overflowing boxes of misc. filters at the old BiG photo shows!!

 

[Jim Jones]

To determine the distance at which a close-up accessory lens focuses a camera, measure the distance at which it focuses the sun or some other distant light. The close-up lens should focus your camera at that distance when the camera lens is focused on infinity.. You might want to confirm this the next time you have a few shots to use up before developing a roll of film.

 

[Helge]

To determine the distance at which a close-up accessory lens focuses a camera, measure the distance at which it focuses the sun or some other distant light. The close-up lens should focus your camera at that distance when the camera lens is focused on infinity.. You might want to confirm this the next time you have a few shots to use up before developing a roll of film.

Thank you! That was easy. It’s the Minar 50, aka one meter infinity focusing.
I figured something like that was the ticket, but for some reason focusing a perfect image of the sun never crossed my mind.

Now that we are at it..
Can you tell me how you’d, in a pinch, use something like a loupe or a lens for diopter? We have determined how to get the focal length, but how close to do you put it to the taking lens?
As close as possible, and stop down?