Mounting the Bolex Moller 16/32/1.5x

[ergopossum]

I recently shot a teaser video for a feature film I'm developing. I'm aiming for a slightly analog look so I've been using AIS Nikkor lenses with the Bolex Moller 16/32/1.5x adapter lens mounted to them. The Bolex has a 39mm filter thread on the back, so I'm able to attach it with a simple 39mm to 52mm ring. However, the only way I can align the anamorphic lens with this adapter is by keeping the filter thread screwed slightly loose, and rotating it to the right alignment, then sticking it in place with a thin strip of tape.

 

This works alright, but I'd like to figure out something more stable for purpose of a feature film. I've looked fairly extensively at the clamps available online, but I can't find anything (Redstan or otherwise) that is specifically tailored to fit the somewhat atypically shallow rear element of this lens, and I wondered if anybody else has had experience with this? I just need a solution that won't add a very substantial amount of length/vignetting to the lens, and will allow me to lock its alignment down. The tape solution results in slight, noticeable shifting around every time we refocus the lens.

 

Thank you!

 

Here's the teaser, shot it on an NEX-5n with the aforementioned lenses. Looking into filming the feature on a C300 or a Scarlet.

 

http://www.youtube.com/watch?v=sgqLqHZk3-A

[JohnBarlow]

The back with the name on it, is it fixed. ?

 

If so I might have a soution, please post diameter and depth behind the knurled focus ring

[ergopossum]

There's a larger black metal ring that was a part of the lens. It wraps around the 39mm thread (which is male) and adds some bulk to the rear element; I normally remove this black metal ring in order to mount with my stepping ring instead. The black ring does not have threads on its exterior, and it doesn't stay attached to the lens very well; often, it will come off of the lens from the unscrewing motion.

 

I seem to have misplaced the black metal ring portion (I might be able to find it if it's essential, I certainly intend to find it eventually) but here is the photo of the main lens. Only the black portions on the top are separate from the focus ring.

 

The protruding element on top is about 10mm tall and has a diameter of 39mm; the larger black area's flat portion has a diameter of approximately 6 cm.

 

[JohnBarlow]

Ok so the silver name ring is part of the focus ring.

 

 

The simplest solution is to screw on the 39/52 step ring tight and screw the lens to the 52mm end.tight

 

Now unwind the step ring (keeping it locked to the lens) until you have perfect alignment.

 

Now measure the distance from the black back face of the Moeller to the step ring and call it Z

 

Now purchase a Nitrile Rubber O -ring of thickness 2 x Z and Inside Diameter 37mm - yes 37mm!

 

Remove everything and fit the O ring first and then Step ring and then lens until you have a pressure tight fit with perfect alignment

[ergopossum]

That's a very creative solution! Have you done something similar? I'm not finding a place online to get these nitrile rings to such specific specifications (seems like it'd be fractions of a millimeter in thickness if I understand correctly) and there's also the consideration that I need to be able to mount and align it onto several different lenses, each of which has varying thread alignment.

 

Seems like the clamp would be the only way to achieve that kind of leeway. Or perhaps some sort of rotating 52mm filter that can be locked into place?

 

The other thought that occurred to me was 3D printing small plastic rings that would mimic the o-ring idea. Perhaps a set of o-rings would be a good solution, I'm just not familiar with it and don't know of a service that offers that kind of precision.

 

I found the ring I mentioned, if this makes any difference. it is 8mm tall, and 5 cm in exterior diameter.

 

[JohnBarlow]

http://www.ebay.com/sch/i.html?_sop=10&_sacat=0&_from=R40&_nkw=nitrile+rubber+o+ring&LH_PrefLoc=2&_lncat=0&_arm=1&_armm=94&_ruu=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2FCameras-Photography-%2F625%2Fi.html%3F_sop%3D10%26_from%3DR40%26_nkw%3Dnitrile%2Brubber%2Bo%2Bring%26LH_PrefLoc%3D2%26_arr%3D1&_armi=Cameras+%26+Photography

 

 

Get a ring for each lens

 

Don't forget to give me a credit in your movie :P

[ergopossum]

It appears that ebay only has one listing of rings with a 37mm inner diameter, and all the rings in that listing have the same thickness. For this to work, I'd need something a lot more specific than that, right?

[JohnBarlow]

build up the thickness - use 2 or more rings :)

[ergopossum]

Thanks. Have you had success with a similar method? The problem I'm thinking about here is that the rings are all 2mm wide, and the alignment would probably have to be precise to a smaller degree than that from what I'm seeing.

[JohnBarlow]

What is your distance Z?

 

Stack 2 of these will do it

 

http://www.ebay.com/itm/10-Pcs-Black-Nitrile-Rubber-O-Rings-NBR-Seal-Grommets-38mm-x-48mm-x-5mm-/310580417872?pt=BI_Heavy_Equipment_Parts&hash=item4850091550

[ergopossum]

The Z distance is about 3.2 millimeters when the anamorphic is aligned to one of my taking lenses. However, it's only about 2.9 millimeters even when I tighten the ring all the way so it's completely misaligned. The entire filter thread is rather shallow. So if I'm understanding correctly the rings wouldn't have enough precision to differentiate between 3.2 mm and 2.9?

[JohnBarlow]

The rings will be squashed under pressure from the step ring at a rate of 0.75mm per turn, go figure :)

 

so only one o ring required the 5mm thick one

[ergopossum]

Are you saying that the ring will make it so snug that it will stay in place wherever I screw it to? (IE even if the lens is refocused)

[JohnBarlow]

That's the general idea , duh!

[ergopossum]

Alright, thanks! I'll definitely give it a try.

[Cineman1]

Shoot Alan at RedStan an email.  He made a run of custom adapters for both the Bolex Moller 8mm and 16mm anamorphots and the last time I checked he still had stock of both.  They give the anamorphot a 52mm rear thread and allow for rotation to align your adapter.  They're a hundred dollars U.S. but it's worth not having to mess around.  They also lock the lens into position so it will not fall off when loosened for alignment.  Just be careful because when loosening the clamp as the anamorphot has a little play forward and back so it's possible that if you mounted it in position farthest from the lens, when you loosen it the adapter could slide towards the taking lens and touch the front element.  Unlikely but worth taking note of.  These are very well made!  And as a side note, the 8mm version also works with the baby Berthiot.  

[Tito Ferradans]

Unfortunately, they're both sold out. I tried to get one for my new 8/19/1.5x, and he told me that. :(

[OzNimbus]

I have to agree:  GET A REDSTAN.  Don't bother messing around with adapter rings.  I have the clamp for my Bolex & it's worth every penny.  If he's sold out, it's worth the wait for a custom one. :)

[Tito Ferradans]

Guys, I don't mean to hijack the thread, but since there are many people talking here, could anyone tell me the difference between the 16/32/1.5x and the 32/1.5x?

 

In pictures, they look exactly the same, but the numbers are different. :(

 

Also, how much does one of these little things weight?

 

thanks! :D

[JohnBarlow]

Isn't one a Moeller and the other a Bolex-Moeller?