IMS Nikon Mount Problem onRED one MX

[Konstantin Seebacher]

Hi,

i recently bought a Nikon F Adapter for the P+S IMS we are using. Problem is; Lenses (P+S digital35 Primes, converted zeiss lenses) have play, it is affecting the image when we pull focus. That is crappy.

can anyone tell me what i could do about this?

thanks

 

[Douglas Underdahl]

I would think that P+S would tell you how to tighten it.

Or you could buy a Nikon Mount for Red One from Red Cine. But I think they no longer sell them.

I might have a few to sell but only if Red Cine won't sell them anymore.

 

[Robert Hart]

Konstantin.


Which of the two Nikon mounts offered for IMS do you have?

One is a simple Nikon-style mount with a chrome pin-release button on one side. You offer lens into mount, twist the lens in the mount and pin clicks to lock. Their "Professional" Nikon mount is heavier. It has a PL-style arrangement. The lens is offered up to the mount. The lens lugs fit into channels. The lens is secured by rotating a ring clockwise until it pull up tight. Some newer Nikon mount lenses will remain loose in the earlier "Professional" mounts if they have been adjusted for an older Nikon lens series. For this reason, mixing and matching old and new lenses into a set is not ideal.

I think P+S fixed the issue by increasing the arc of rotation of the lock ring or using a coarser thread on the altered "Professional" Nikon mount. If yours is an earlier "Professional" IMS-Nikon mount, there is an adjustment available. It may be there in the newer one also.

Take care however that if you insert an older series lens into an early "Professional" mount which is set up for modern Nikon lenses, the lock ring may balk, just barely "grip" the corners of the lugs and turn no furthur. The temptation for operators is to force the ring around. Do not do this. The rotation movement from the outer ring is relayed through slots to an inner threaded rotating section by special shouldered screws. These will loosen and later jam inside or break off immediately if force is used.

With the simpler Nikon-style twist and lock mount, there may be small sprung sections created by cutting slots in metal inside the mount. This leaves thin hanging sections around the inside of the mount, each about 12mm long. These effectively become springs that the lugs on the lens ride over to pull the flange face in tight as the lens is turned until the pin locks. If they are forced flatter by an older lens with a tighter fitting, then they may not apply force to the newer series lens lugs and leave the lens loose against the flange face.

I am not sure if this is the arrangement P+S used. It is a common method with other non-genuine Nikon mounts. If they have become flattened, it is a simple task to wedge them back rearwards no more than about 0.2mm ( zero point two of a millemetre ) with the fine blade of a jeweller's screwdriver. Too much will break them off.

Nikon's own registered design uses a floating ring spring with three raised bows inside a channel behind the flange ring. The lens lugs ride across these into tension as the lens is rotated to the locked position.

An email or phone call to P+S Technik should get you the information you need.

 

[Robert Hart]

Maybe post an image of your mount in the meantime.

 

[Douglas Underdahl]

There are two Red One OEM Nikon mounts.

The earlier one used springs to hold the lens.

The later and current one uses a single rotating stainless ring to hold the lens, PL style.

I made them both.