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Pan Cinor 17-85 Lens for reflex camera?


Gabe Agoado

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  • 1 year later...

The side viewfinder on the lens means the lens was designed for a non-reflex camera.....like basically an older Bolex.

A Bolex that is has reflex viewing nad is a REX series camera....has a beam splitter behind the lens mount......and takes lenses that are marked "Rx".

 

The difference is that the back focus distance is different......so I doubt that the lens would work on a camera that is already reflexed.

 

The lens with the viewfinder would work on an non-reflexed Bolex H-16.....or a CP-16A.

Rich

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Hi Rich,

 

you can use a non-Rx lens like this one on a reflex Bolex, it just gets a bit of abberation under about f/3.5 and as a general rule only at wider focal lengths. Bolex didn't actually commision manufacturers to make Rx lenses over 50mm so for telephoto options you have to use non-Rx lenses.

 

The back-focus of Rx and non-Rx lenses is the same, an Rx lens is just optically computed to negate the aberrations introduced by the prism.

 

I think the confusion comes about because the physical flange depth of a reflex Bolex is longer than the 17.52mm C mount standard, due to the prism refracting the light and causing a lens to form an image further back than it normally would. But this happens to any C mount lens mounted on a reflex Bolex. The lenses themselves, Rx or non-Rx, are still set to 17.52mm back-focus from the mount seat.

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Rich and Dom, I haven't myself noticed any aberration problem on a RX camera, although I mainly use it on longer focal lengths. The big advantage I've found is the viewfinder on the lens, so much brighter and clearer than the camera's finder, so you have a choice of finders. Although it's sometimes too easy to rely on the side-finder's split image for focusing as I once did and I got some soft footage.

A good point Robert made about covering the camera's viewfinder when not in use.

Incidentally, the Pan Cinor also covers ultra-16 format.

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First Post!

Doug, Great lens, I own one for my Bolex rex 1. RX I believe passes %25 of light loss to the finder, however based on my model camera, I plug the finder and use bolexreflex finder for focus.

 

Also, the 17-68 t2.2 from Angenieux is another good lens option for ultra 16. vignetting a bit at wide open. COver my ikonoskop sp-16 wonderfully. Even lighter and smaller.

Cheers!

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First Post!

 

Doug, Great lens, I own one for my Bolex rex 1. RX I believe passes %25 of light loss to the finder, however based on my model camera, I plug the finder and use bolexreflex finder for focus.

 

Also, the 17-68 t2.2 from Angenieux is another good lens option for ultra 16. vignetting a bit at wide open. COver my ikonoskop sp-16 wonderfully. Even lighter and smaller.

 

Cheers!

I hope I didn't give the impression that the rangefinder in the Pan Cinor lens is inaccurate. It's spot on. However, the camera's viewfinder I've found gives a better idea of how the image will appear depth-of-field wise. Also it's imperative that the lens is screwed securely home as even a tiny loosening will affect the focus. One of the weaknesses I suppose of c-mount.

And it's easy to forget that the lens itself looses light by about 2/3 of a stop.

On my lens the focussing ring is quite hard to turn, not sure if this is on other Pan Cinors. The zooming though is very smooth.

Haven't tried the Angenieux...

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I hope I didn't give the impression that the rangefinder in the Pan Cinor lens is inaccurate. It's spot on. However, the camera's viewfinder I've found gives a better idea of how the image will appear depth-of-field wise. Also it's imperative that the lens is screwed securely home as even a tiny loosening will affect the focus. One of the weaknesses I suppose of c-mount.

And it's easy to forget that the lens itself looses light by about 2/3 of a stop.

On my lens the focussing ring is quite hard to turn, not sure if this is on other Pan Cinors. The zooming though is very smooth.

Haven't tried the Angenieux...

I've got a tight focus ring too, I can wear it down a bit by just cranking the ring couple times back and forth. But not the best, I can second that.

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I hope I didn't give the impression that the rangefinder in the Pan Cinor lens is inaccurate. It's spot on. However, the camera's viewfinder I've found gives a better idea of how the image will appear depth-of-field wise. Also it's imperative that the lens is screwed securely home as even a tiny loosening will affect the focus. One of the weaknesses I suppose of c-mount.

And it's easy to forget that the lens itself looses light by about 2/3 of a stop.

On my lens the focussing ring is quite hard to turn, not sure if this is on other Pan Cinors. The zooming though is very smooth.

Haven't tried the Angenieux...

I've got a tight focus ring too, I can wear it down a bit by just cranking the ring couple times back and forth. But not the best, I can second that.

 

OK Bob thanks I'll try that. At least it's better than too loose. But far too stiff for changing focus during a take. How would you compare this lens with the Angenieux ? Is the viewfinder similar ? It's good to have a dogleg lens like this that can be utilized on almost any old non-reflex camera. The 2/3 stop light-loss on the Pan-Cinor is maybe too kind, probably nearer 3/4...

Edited by Doug Palmer
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If the focus ring is stiff it's usually because the lubricating grease has dried out. (The other possible cause is that the barrel has suffered an impact and is deformed, but most commonly it's just the old grease.)

 

If you're game, it's not too hard to relubricate the focus section of older zooms like a Pan Cinor. The focus on lenses like this is a front optical group in a housing that simply screws onto the body of the lens. To remove it in order to clean and regrease the threads you need to remove the outer focus scale to access the stop underneath that limits the focus travel and stops it from screwing right off. Once the stop is removed, you can unscrew the focus group to clean the threads with a white spirit or lighter fluid (a tooth brush works well) and relubricate. Try to avoid spattering the glass, but if you do just clean with isopropyl alcohol on a tissue before reassembly.

 

The really important thing is to mark where things go as you disassemble and to measure the gap between focus group and body at the infinity setting, so that you can get the settings back. The thread will have multiple starts, so mark exactly at what point around the barrel the front group unscrews (mark both parts so that you can line the marks up to screw them back together).

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Thanks Dom for that information. I'll maybe tackle this. Along with the GIC 24fps job ! As with all these kind of jobs, there is a fear somewhere in the background that things may not work out and could bring on more problems, I mean when one has a camera or lens that is perfectly OK otherwise. So not sure about the Pan Cinor.... if fungus was there I'd certainly dismantle.

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