S16 pl to pl focal reducers, and can you shoot in normal 16mm on a 416?

Edith blazek · November 1, 2022

Hello, has anyone made a pl mount to pl mount focal reducer for super 16 cameras?

I want to use larger format lenses on super 16 film cameras with lenses like the 12mm master prime, or the 18mm tokina and it's derivatives. I don't want to pigeonhole myself into buying a whole bunch of super 16 primes (before you ask, no one in my area offers any motion picture film cameras), but I want to use them to their fullest image circle wise while on super 16 as I feel it within the world of the available film stocks like vision3 it still has texture comparable to old film stocks but I want the perspective that shooting a super 35 or larger camera would force me to do in terms of distance from the subject relative to the field of view. So y'know how there's pl to pl focal expanders? Has anyone made a pl to pl focal reducers then?

Also, can you convert a 416 to shoot regular 16mm like you can with an sr3? I just want to know as another element of which to buy.

Edited November 1, 2022 by Edith blazek

Robert Hart · November 1, 2022

There exists no PL-PL focal reducer. There is also not enough workspace between the PL-Mount and the mirror of a reflex 16mm/Super16mm camera for the optics of a focal reducer to fit.

How would I know, some might ask. I have installed focal reducers in the SI2K digital cinema camera and the original "big" Ursa digital cinema camera. Even with the deeper available workspace between rear of the lens and the IR filter in these cameras, it was doable - "just".

Before affordable focal reducers like the Metabones Speedbooster came along, folk were using groundglass based non-coherent image relay adaptors like the P+S Technik Mini35, Pro35 and the many alternative adaptors which followed. I tried this in a rough and ready arrangement on a CP16R film camera. The image was not outstanding, primarily due to the relay optics being matched for 1/3" video cameras, not the near-to 2/3" image area of the 16mm film.

You lose up to one and two thirds of light in conditions requiring wide open lens aperture and there are two focusing systems to contend with.

By the time one could cobble up a means of relaying the field-of-view of a 35mm motion picture frame to the 16mm motion picture frame, it would be far cheaper to buy 16mm/Super16mm motion picture camera lenses and a lot less frustration when using them.

Over on www.reduser.net there was discussion about a focal reducer which adapted medium format lenses like Mamiya 645 types to RED cameras. What the distance is between the rearmost optical element of that adaptor and the film plane is I have no idea.

Phil Rhodes · November 1, 2022

What I'd really like to see is for Blackmagic to move the sensor on the Ursa Mini a lot, lot closer to the mount, so we could all have speed boosters on their cameras.

Robin Phillips · November 1, 2022

part of the problem with speedboosters on a film camera is that the added optics tend to wind up where your spinning mirror is, which makes for a very bad time. I may have spent quite a bit of time looking into this a few years ago and every option I found that didnt require manufacturing new glass was going to make my sr3s mirror go shatter shatter

I dont remember if you can convert the 416 to n16, but Im not sure why you would. You can put a 1.33 fiber screen in the camera that will be the N16 format but centered. Then you can just crop the sides off. If you can't find a fiberscreen like the one you need, AMCamera and Shruco tool I think can still do new frameguides on a fiber screen if you have a donor one you're willing to have changed. Herman over at Cameramarket.eu had a stockpile a while ago but you'd have to ask him what hes got left now.

If you do want to use master primes on the s16 format, you basically need either a 416 or an Aaton camera. the Master primes barely fit on an SR3, and require you to contort the viewfinder in weird ways such that it makes shoulder operation effectively impossible. Even then I dont know if all of them will mount up, I've just seen it done once and I unfortunately cant recall which lens it was. But if master primes are in your budget then I suspect a 416 or xtr is too, so probably wont be a problem

Nicholas Kovats · November 1, 2022

Excellent analog research, Robert Hart. Well done.

We live in a world fraught with a plethora of lens options. ?

Robert Hart · November 2, 2022

Phil Rhodes.

I assume that your comment "moving the sensor closer to the mount" also suggests using another mount system which is closer to the sensor and has universal adaptors.

On the SI2K I was able to modify a speedbooster for Nikon F-Mount for the original Blackmagic Pocket camera to offer into the P+S Technik IMS-Mount, (a universal mount) which is just 0.25mm shy of the M/43 flange to focal plane distance. It was doable "just". It could not be done for the Canon EF-Mount.

In the Mini Pro camera family, the ND filter wheel enclosure on front and the IR filter, there might be some problems in redesigning the front lens mount support to be closer to the sensor to enable a universal mount system. BM more or less offers this anyway in the Mini Pro camera family with the choice of mounts to fit on front of the existing lens mount support.

Lucadapters offer indwelling speedbooster adaptors for the Mini Pro camera family. I am not sure how Luca got around the infinity focus problem but a thicker planar element replacing the existing IR filter would solve it and I think that is how he got around it.

Edited November 2, 2022 by Robert Hart
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Phil Rhodes · November 2, 2022

34 minutes ago, Robert Hart said:

Lucadapters offer indwelling speedbooster adaptors for the Mini Pro camera family. I am not sure how Luca got around the infinity focus problem but a thicker planar element replacing the existing IR filter would solve it and I think that is how he got around it.

Aha! Someone has actually done it! I had no idea that was even on the market. Do you happen to know when that became available?

But yes, in general, I would like to see a shallower mount on the Ursa series. Whether that's some sort of bolt-on universal mount system, or just micro four-thirds, would be fine, although I think MFT is perhaps a little small and fragile. Maybe something larger would be better, although I would point out that JVC managed to fit a rotating filter wheel, IR filter and a super-35mm sensor behind MFT on the GY-LS300 camcorder, so it can be done.

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Robert Hart · November 2, 2022

I think the first Lucadapter may have been for the older Ursa Mini 4K so they have been around for a while.

These were my speedbooster mods for "big" Ursa 4K with the modified mount removed and the modified IMS-Nikon F-Mount Speedbooster. Luca went one step better and was apparently able to make a workable Ursa Mini Pro version.