Is there a 35mm adapter with Leica mount?

[Jens Matthies]

I'm entertaining the idea of using a Noctilux 50mm f/1.0 lens with a 35mm adapter. Is there an adapter with a Leica mount? Another option would be to use some kind of converter from the Leica lens to a Nikon mount, but this might yield issues with projecting the image properly for the camera?

Any information on this would be highly appreciated.
Thank you.

- Jens

[Bill Porter]

First off, there are multiple Leica mounts, so for the Noctilux you need a Leica M mount.

Yes, there are converters from Leica M to Nikon F mount. Some companies selling them say the converters they offer don't have glass elements and do allow infinity focus. Off the top of my head I don't see how this is possible since Leicas have very short lens registration distances, meaning, the distance from the lens mounting flange to the film plane is very short. It is my understanding that Leicas have distances shorter than the 46.5mm Nikon mount, so I do find it interesting that some companies claim their mounts allow infinity focus. You should ask them. One is cameraquest.com, though the guy is a total cock.

[Joel Kreisel]

Assuming you're building it yourself, the difference in flange distances between the two mounts shouldn't be an issue since you can place the ground glass wherever you want. So just get a mount adapter without a rear lens and place the ground glass like you normally would to get the complete focusing range.

[Jens Matthies]

Thanks for the info guys!
I would never attempt to build a 35mm adapter myself (too much of an idiot), so what I'm really curious about is wheter or not there is an existing adapter out there (MPIC, M2, Letus etc.) available with a Leica mount?
I think the Mini35 does have a Leica mount, but I'd rather not dish out the cash for that beast.

- Jens

[Ben Winter]

The Letus GG distance can be easily adjusted by heating the hotglue on the three sticks and sliding the plate up or down. The only issue I could see is if you needed the ground glass farther away than 42mm, in which case you'd have to ask Quyen to not cut the sticks down as short, or something. So, you could buy the Letus with the metal mount and get a Canon to Leica mount or Nikon to Leica (the Letus metal mount is switchable), and go from there.

[Bill Porter]

Originally Posted by Joel Kreisel

Assuming you're building it yourself, the difference in flange distances between the two mounts shouldn't be an issue since you can place the ground glass wherever you want. So just get a mount adapter without a rear lens and place the ground glass like you normally would to get the complete focusing range.

That's the problem. You can't adapt a lens with a shorter registration depth, onto a mount that sticks the adapter and new lens out past where it needs to be.

For example, let's say (and this is only for the sake of example; these numbers are made up) that a Nikon lens mount requires the film plane, or GG, to be 4" away from the lens mount, and that a Leica lens mount requires the film plane or GG to be 1" away. Now let's say you want to use or make an adapter that lets you mount a Leica lens onto the Nikon. Well, it won't give you infinity focus unless you add an optical element, because the Leica needs to be 1" away from the film plane yet the Nikon mount forces it to be 4" away.

So that's why I'm wondering why the short (27-point-something millimeter) registration depth of the Leica M can work with a Nikon F with its 46.50 distance. I do know there's something goofy about Leica mounts since there's something about a 40mm component that goes in there in addition to the 27-point-something mm depth. Maybe that, with its ~68mm total depth is why some companies can offer a Leica M to Nikon adapter with no optics that still has infinity focus.

[Joel Kreisel]

Bill, I'm still not understanding why that's a problem, assuming you can physically fit the ground glass and lens on the tube. The mount itself is not optical so it doesn't have an inherent registration depth, just the lenses you use on it have a particular depth. For example, if a Nikon adapter looked like this:

Nikon--------GG---camera

Then with the Leica adapter, you're just adjusting the location of the glass to account for the different registration depth of the lens:

Leica----GG-------camera

Of course, as I said earlier, this would only be true if you were making it yourself so you could set it (or bought one like the Letus that can be moved fairly easily). If you didn't want to do any DIYing though, you'd definately have to have an adapter with a lens.

[Bill Porter]

Originally Posted by Joel Kreisel

The mount itself is not optical so it doesn't have an inherent registration depth

Ah, but it does have an inherent registration depth or length, because of its own length. Some mounts themselves are longer than the entire registration depth of other brands of lenses(!)

Also, I think your confusion is over what the term "adapter." I am talking about adapters or converters that you place onto a lens mount (say, Nikon) that let you fit up a different mounting style of lens (say, Leica). I am not talking about 35mm adapters, I'm talking about lens mount adapters, because Jens was asking about "Another option would be to use some kind of converter from the Leica lens to a Nikon mount." Dat's all!

[Andrew Todd]

queyen's letus is easy to adapt for your own particular use.. ive replaced the sticks with replacement syringe sticks.. really easy to take apart and change.