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Converting Zeiss ZF to PL?

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IanK

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Just wondering if it were possible to convert Zeiss ZF lens to PL mount? How much would it cost? Please let me know. Thanks



Ian
 
Yes and no. The flange depth is just too short, and the iris sits very far back in the lens. It would require a very expensive re design. The PS+technik folks decided to leave them Nikon mount because it is just to expensive to re-engineer them. By the time your done each one would be the cost of a Cooke prime.
 
Probably a pretty penny. If you don't mind doing mount swaps, one other way you could go would be to have the mods done by a company like RP Lens and then use something like View Factor's gears to get some control over your still lens mechanics.
 
I own a nikon mount. I was under the impression that the the camera had to be collimated each time the mount was changed. Is that not the case.
 
IanK said:
I own a nikon mount. I was under the impression that the the camera had to be collimated each time the mount was changed. Is that not the case.
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What do you mean? Isn't it necessary to collimate?
 
It is necessary to check the collimation and you should have a large monitor to do so.

The ZF lenses would require far more than a simple mount change. The entire lens would have to be rebuilt in a new housing with all new mechanics. Thousands of dollars at best.
 
Mitch, How do you check the collimation?
 
Use a wide angle lens with a fast aperture. The lens itself needs to be collimated beforehand on an optical bench, because it is now going to become your standard. Point it at a large focus chart at a decent distance, say 10 feet, but it has to be something with a definitive mark on your lens. Open the aperture all the way. set the lens at the proper distance on the ring. Adjust the RED's backfocus adjustment (unlock that pair of clamping screws on the lens mount) until the image appears as sharp as possible. Be sure to view the image on a large monitor with the focus assist zoom in feature activated in the camera menu. Get the image as sharp as possible by adjusting only the backfocus. Save a short file to a CF card and open it up in software where you can actually see the full resolution of the image so that you can judge if it is actually sharp. If not then you'll have to dance between the adjusting it and rechecking the file on the computer.

Just checking in the viewfinder or onboard monitor is a mistake. Just checking on a monitor in 1280x720 (zoomed in to a virtual 2560x1440) is still around half the res. of the actual image. The only way to accurately judge focus in 4K is in 4K.
 
..as Mitch stated, but in addition i would also check on two more different distances. For determining right focus it helps to record a clip where the distance setting on the lens is dead on the witness mark and another two clips slight under and over the mark, so you can compare to each other.

Manuel
 
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