I am commenting from my experience of using a variety of Nikons on P+S Mini25-400 adaptors and SI2K cameras. What follows below may be utter rubbish relative to the RED camera family.
There are Nikons, old Nikons and older Nikons and third party Nikon mount lenses. Whilst they conform generally to the Nikon F-Mount, there are some subtle differences which may cause problems with positive lock versions of the Nikon mount profile like a small few very early specimens of the P+S IMS "Professional" Nikon mount before it was revised. I don't know the Optitek but the first things I would be looking for are :-
Lens rear flange face not seating dead flat on the mount flange face.
1. If the Optitek mount is a positive lock style with a solid pin and rotating collar, check that the channel in back of the lens for the locking pin is a tidy fit and not hanging the lens high through being either too tight a fit or not deep enough and bottoming out on the pin-end. (The fixed locator pin on the P+S "Professional" mount was an interference fit, with the pin only partially inserted into a deeper hole. It was designed so that in the event of a misfitting lens and excessive force used to close the mount, the pin would press into the hole and distortion damage be averted. The pin then needed to be reset by partial dismantling of the mount.)
2. If the lens is an older Nikon with an overhanging iris ring, an okay fit on the older 4 x screw FM2 style mount ring, the iris ring may be riding on the mount if it is the newer profile with its 1mm shallower outer clearance shoulder relief depth and slightly wider diameter.
3. Some older lenses have a slightly deeper distance between the flange face and the face of the bayonet lugs. These lenses may not tighten securely but hang, causing the tilt-shift referred to. They may seem snug but this may be the models with the mostly cutaway iris ring overhang holding them firm just enough for the ring to be adjustable but the lens not feeling sloppy in the mount. There are two fault events happening here, one counteracting the other creating an impression all is well. The outcome is the tilt-shift effect.
4. Bent fixing of the mount ring on the rear of the lens barrel. In some lenses, the fixing of the mount portion to the barrel of the lens might be via screws on axial centres. If the lens has been forced or bumped such as in a heavy tripod nose-over, such screws might have become pulled or the narrow fixing rim bent in a ripple pattern ever so slightly between the screw centres. The lens barrel itselrf or attached components may have become bent. The lugs themselves may have become bent and allow the olens to hang off centre axis slightly.
I am speaking for the modern Nikon film cameras with 5 x screw style mount rings and the very early P+S IMS-Nikon "professional" mount which was soon revised to fix the issue.
I doubt the Optitek mount quality control on the machining work is the issue when a prestige product like the RED is being catered to. Parallel faces should be no problem to achieve, even with my old back shed lathe and my bad close-up eyesight. I expect it is more likely a rear of lens problem. If it is a machining quality problem with the Optitek mount, then they won't be trading for too much longer with RED's blessing.
If the Optitek mount is the traditional Nikon twist and releasable latchpin style, then much of what I have mentioned above related to positive lock mounts is irrelevent. The same issues will be present relating to slight difference in the mount profiles on older lenses.
I hope this guides you usefully and is not the precursor of a goose chase.
Last edited by Robert Hart; 05-25-2012 at 10:25 AM. Reason: error
None of this really applies here, each mount is verified flat, tested for lens fit and locking. The locking mechanism on the proLock is completely different , no metal on metal grinding and the subsequent lens mount wear. The prolock is actually gentler on the lenses than the original Nikon spring loaded mount. We had some loose lenses but these were very old Nikons with a dire need of mount replacement after 30+ years of use on Nikon cameras. I don't think 30+ years of use on the ProLock would wear them out so much. I guess we'll see in 26 years....
I doubted there was a quality control issue involved. Older Nikons may have lived hard, even if they appear mint and shiny. The rear section is rather narrow to hope that some changes do not happen there with time and little accidents.
You might be all wearing plastic bibs with catchers being spoonfed in care homes, valiantly resisting the prising of your EPIC/SCARLETTS from your cold bony hands by the time the mounts wear out do you think?
|« Previous Thread | Next Thread »|