Call for C-mount lens info
 

C-mount lenses are coming back into fashion for people using scientific/industrial box cameras for creative video production. It can, however, be a problem to know what to buy and what to avoid. Buying new needs care: most of the inexpensive C-mount lenses are not high definition and only intended for CCTV security cameras. I've found it difficult though tracking down information on the older lenses originally used for 16mm cine cameras.

The C-mount screw thread can come in different diameters: 1", 2/3", 1/2". The accepted standard is the 1" format. Also be aware there is CS-mount; this uses the same thread as C-mount, but has a different flange distance (the lens shoulder to sensor/film plane distance): C-mount = 17.526mm; CS-mount = 12.526mm. You can easily get a CS-to-C mount adapter. Watch out for C-mount lenses (eg. Switar lenses) made for 16mm Bolex reflex cine cameras (such as the RX5). These lenses are marked "RX" and have a non-standard flange-to-film distance to accomodate the reflex prism in these cameras.

There are some great C-mount lenses out there to buy second hand: Zeiss, Cooke, Kinoptik, Schneider, Angenieux, Bausch and Lomb, etc. I include below (in separate posts so it'll be clearer to read) information that I have so far, which isn't that much! To avoid repition, assume all lenses are 1" C-mount format unless otherwise indicated. I'm hoping contributors will join in with more information, plug the gaps, make corrections, give personal recomendations, suggest places to buy (I suppose we already use ebay as a catalogue!), provide useful links, etc. It might build into a useful resource; the cameras are nothing without good lenses...

Regards,
John.

Schneider lenses
 

Schneider lenses
These are professional quality lenses. I received a helpful email reply from them which provided most of the info below.

www.schneideroptics.com

1" C-mount primes
10mm Cinegon, f1.8, filter thread = 55mm.
16mm Cinegon, f1.4, filter thread = 35.5mm.
25mm Xenon, f0.95, filter thread = 39mm.
25mm Xenoplan, f1.9, filter thread = 30.5mm.
50mm Xenon, f1.2, filter thread = ?
50mm Cinegon, f?, filter thread = ?
360mm Alpha Tele-Xenon, f4.5, filter thread = ?

2/3" C-mount primes
17mm Xenon, f0.95, filter thread = 35.5mm.
17mm Xenon, f1.7, filter thread = 30.5mm.

2/3" C-mount zooms
12.5-75mm Variogon, f1.8, filter thread = 52mm.
10-100mm Variogon, f1.8, filter thread = 77mm.

Angenieux lenses
 

Angenieux
This manufacturer has a good reputation for lenses suitable for professional use. I couldn't find any mention of the older lenses on their website, and currently no reply to my email request for information.

www.angenieux.com

Primes
5.9mm, f1.8, filter thread = ?
10mm, f1.8, filter thread = ?
15mm, f1.3, filter thread = ?
15mm, f1.8, filter thread = ?
25mm, f0.95, filter thread = ?
25mm, f1.4, filter thread = ?
50mm, f2.0, filter thread = ?
75mm, f2.5, filter thread = ?

Zooms
9.5-95mm, f2.2, filter thread = ?
12-50mm, f2.5, filter thread = ?
12-120mm, f2.2, filter thread = ?
12-240mm, f4.8, filter thread = ?
17-68mm, f2.2, filter thread = ?
17.5-70mm, f2.2, filter thread = ?
20-80mm, f2.5, filter thread = ?

Bausch and Lomb lenses
 

Bausch and Lomb
Sharp lenses but for some reason underrated and therefore quite cheap. Not much info to list here at the moment!

Primes
1-inch Animar, f2.7, filter thread = ?
26mm Animar, f1.9, filter thread = ?

Using 35mm SLR lenses
 

You can easily get C-mount adapters to use manual 35mm SLR lenses; most brands are accomodated -- Olympus, Canon, Nikon, Pentax (M42 screw and K bayonet), Minolta, etc. However, the narrower field of view (using only the middle portion of the still camera lens) means you can expect up to a 6x increase in effective focal length compared to the original 35mm values. If you like shooting with long lenses this will be an advantage; if you need wide angle shots you'll be disapointed. You can get adapters from:

www.srbfilm.co.uk
www.edmundoptics.com

"""""""""""The C-mount screw thread can come in different diameters: 1", 2/3", 1/2". The accepted standard is the 1" format."""""""""""""



There probably needs to be clarified, that the common C-Mount is the 1" (25mm??) as I understand it. C-Mount lenses listed at Fujinon for the different applications including some newer sharper lenses are described in charts being 1/3", 1/2", 2/3", 1". This refers to the area of image thrown by the lens at the film plane.

""""""""""""Also be aware there is CS-mount; this uses the same thread as C-mount, but has a different flange distance (the lens shoulder to sensor/film plane distance): C-mount = 17.526mm; CS-mount = 12.526mm. You can easily get a CS-to-C mount adapter. """"""""""""""

As I understand things, you can use a C-Mount lens on a CS mount camera by adding a spacer which is about 5mm thick. You cannot succesfully fit a CS mount lens on a C-Mount camera unless you want to use it in a permanent close-up (macro) application such as a home-made video assist.

"""""""""""""""""""""There are some great C-mount lenses out there to buy second hand: Zeiss, Cooke, Kinoptik, Schneider, Angenieux, Bausch and Lomb, etc. """""""""""""""""""""""

Some of the older Schneider-Kreuznach lenses for non-reflex Bolex will work on small-chip 1/3" or smaller cameras but for 1/2" or 2/3" such as JVC KY-F50 and KY-F32, the image area is sometimes a bit tight and there can be a vignette in the corners. I would not be inclined to separate these from any vintage camera they might be installed to as added usage will subject them to risk of damage or loss.

On ebay, two older C-mount lenses for older tube video cameras turn up from time-to-time. These are from the old Sony cams, the Tamron 12.5mm - 75mm zoom lens, aperure f1.8. - closed. I used this lens for stringer news work on a non-reflex Bolex and later, RX5 Bolex. There is a Canon 17mm - 85mm?? lens which was fitted to the first generation of Panasonic colour VHS portapack style systems. These were consumer grade lenses.

There is a scarcer lens which turns up from time-to-time, a Fujinon 16mm to 160mm f1.8 lens. "TV-Z". It is larger and heavy but is a good light collector. It is a bit heavy as a C-Mount lens, possibly damaging to a small security or scientific cameras. As there is no tripod support built into this lens, one has to be innovated around an adequate shoulder in the lens body. The C-Mount on my specimen of this lens appears to be an adaptor option, retained by a threaded ring.

The lubricants are likely to have dried off and the lens movements baulky and stiff ion these lenses.

Cap'n Lensmeat
 

Avast ye

On a DIY camera them be fine... but fer those of ye thinkin of using C-mount lenses on a shallow-DOF-adapter, wit ye're C-mount lenses ye got a much smaller image circle, ay

This be meanin ye'll have much bigger grain from ye're GG

Arr matey

I'm discussing the same thing with someone who uses the Elphel (1/2 inch) CMOS camera. He's not really happy with his computar C-mount lens (is that a TV lens?) So he ordered a SLR-canon to c-mount adapter.
What lens do you guys (and Bill) think he should try out to get a decent field of view? Say you have an 28mm lens, would it be somewhere near 50mm or 55mm or a lot bigger?

Ay be tinkin moast thu ludd's mart bi contemplartin offrin' oop thu see-mount lins tuh thu vuddio carmara uz uh riillay lins. Uz uh varliid commintarry yuh be arferrin compadre.

Arz loong arz we be piratin oon thuh har sees an noort the viddeo undustry we be sairff. -- mebbye. Narr beck to grarndin, un cuuttin, un glooin, un mairkin gard fillums.

Oscar, are you asking whether a 28mm SLR lens on a 1/2" chip camera, compares to a 50mm or 55mm SLR lens on a film camera, in terms of field of view?

If so, I don't know, as I'm not that well-informed on the cropping factor of a 1/2" chip camera, but I do know that it still will have plenty (of cropping factor).

This is a great link on the subject of actual chip sizes (it ain't 1/2"!) and of field of view:

http://www.navitar.com/zoom/cctv_op_char.htm

As is this:

http://www.dpreview.com/news/0210/02...ensorsizes.asp

Thanks Bill, that's what I meant. Those links are very helpful indeed.

No problem. As payment you may paint a picture of a Heinkel Kabine for me. You have my address.

You have to give me a lot more good answers to make me paint that little...

If it's such a little painting I don't see the problem...

The short flange depth of c-mount lenses makes them poorly suited for relay lenses. The distance from the ccd to the IR filter in a Canon is about 30mm.

1-inch CCD C-mount camera lenses
 

I was making a list of low light superfast lenses..Planning to use a 1-inch CCD GigE camera for making a film..
So far I have the
Schneider Xenon 25 mm f/0.95 C-Mount Lens for 1-Inch CCD
and
Angenieux 25 mm f/0.95 C-Mount Lens for 1-Inch CCD
Fujinon 16mm to 160mm f1.8 lens. "TV-Z" (Is this for 1-inch sensor cameras)

Are there any other lenses from 1-inch sensor tube cameras I could use ?
Would be great if I could troll ebay and pick some super lenses..

Fujinons range do have specific lenses for the 1" sensors (f1.4 too) but check carefully as there's only one letter between them and the 2/3rds image circle versions.

the 25mm will end up as 60mm focal length on this sensor, and i doubt the f0.95 is very sharp. Also i think you'll find that f0.95 will be damn near impossible to nail focus in the field! f1.4 is good enough for a nice shallow DOF. I assume you're using the KAI2093 sensor? Which head?

cheers
paul

The Fujinon 16mm - 160mm f1.8 TV-Z is as far as I know, only a 2/3" lens. I know it works on the Bolex for 16mm film and on the JVC KY-F50 camera head which is 2/3' optically relayed to 1/3" sensors. The resolution of this lens may not come up to your requirements.

It is older generation and softer than a prime lens, but sharper and better contrast than the ex-home video zooms I mentioned in the earlier post above.

If you have a full 1" sensor to play with, it might be worthwhile looking at a C-mount >> Nikon adaptor and using some Nikon glass for your longer lenses. Their 35mm f2 is supposed to be as sharp as the older f1.4 at f2. Sigma for NIkon 20mm f1.8 is a bit soft wide-open.

I've used a canon c mount adaptor with my 10-22mm which can produce good results on a 1" (obviously with the EF lenses they are open full as the adaptor cannot control the iris). However the 10-22 is a pretty slow lens and nigh impossible to manual focus (focus range is too short). Aside from that it's very difficult to find a wide and fast SLR lens. The best you're going to get is 14mm f2.8 or thereabouts. I think decent machine vision lenses are the best bet for 1" (all 16mm and S16 lenses have image circles that are too small -- i've had cookes and the 10mm f1.6 switar on there). I've not been able to test the schneiders though, would love to get my hands on one. And that computar zoom looks interesting (on the sumix thread)

a 35mm would be an 85mm on this sensor, which is too long for most uses. The 20mm more usable though.

cheers
paul

c10x16a-snds21 Fujinon
 

I am going to use a Prosilica GE-1900C camera. I searched for 1-inch lenses.. This lens c10x16a-snds21 shows as a 1-inch zoom lens on Fujinons website..

http://www.fujinon.co.jp/jp/products...16a-snds21.pdf

Would this work ?

Also, if use a c-mount nikon adapter - how does the light performance go ? If I use a 35mm lens - not all the light that goes through the lens will reach my sensor..Thats why I am not too sure about adapters..Am I wrong in thinking this way ?

the adaptor won't loose any light, it's just to phsyically get the lens on there at the right distance from the sensor. the image circle of the nikons will cover a lot more than that sensor though. You will experience a crop factor, each lens will have a field of view 2.5 times the stated focal length, so a 16mm fujinon will be more like a 42mm lens on a 35mm camera.

No light loss though.

The prosilica is a nice head, i've been testing one for a few weeks, i'd be interested in hearing how you get on with it.

I don't think that's the fujinon im thinking of, that seems to be a zoom, im talking about their range of primes.

cheers
paul

Lenses
 

Can I check the exact details of the lenses you are using ? Like the model - that I can search for, and pricing ?

I am using it for a feature so I need a range of primes..

Help really appreciated..

Thanks!