C-mount lenses on Micro Four Thirds

One of the great things about the micro four thirds format is that you can simply mount anything on these. It’s just a matter of finding the right adapter, among the variety of available offers. In this particular case, the C-mount to M43 one pictured above is indeed well made, but there are cheaper ones starting from just a few bucks.. Fotodiox comes to mind.
C-mount lenses are still in use,  no longer as 8mm or 16mm cinema lenses as they used to be but as security devices lenses, namely closed circuit television lenses. Normally they are pretty fast lenses as they need to work 24h and they come under the commercial term of TV lenses (from the CCTV acronym).
This is why some may be interested in the vintage C-mounts on a cropped sensor. Fast glass is expensive and C-mounts are not.

Bolex cameras were very popular in both the 8mm and 16m world,  that much the guys over at Digital Bolex thought it could be commercially viable to financially venture into a revival.

I myself have been tempted by the whole C-mount business,  best thing is always hand on.  Names like Angenieux and Cooke do appear in c-mounts variants,  as in old movie lenses, and suddenly you start thinking how nice it would be to have them on you next shooting session not for too much money …or at least nowhere as much as a Cooke S4 or an Angenieux Optimo. I had my fair bit of C-mount knowledge from experience .

There are some things that have to be said thought.
First issue relates to the focal length.  You cannot go any wider than 22mm as the lens will indeed vignette at best or porthole in worst cases scenarios. Actually the term vignetting is not technically correct, we should say there is a the mismatch between the original intended mount and the real mount.   On the micro four thirds format the sensor is nearly a super 35mm,  close in size to the Aps-c format,  anyway horizontally and vertically bigger than the  16mm format those lenses were originally designed for. We could say that the Micro 4/3 sensor is 20% wider than 16mm.
You can refer to the below summary that I found on a Google Spreadsheet as a reference between focal lengths and sensor coverage, compiled by some good soul :-)

 

MANUFACTURER MODEL FL  MAX AP   SENSOR COVERAGE  DETAILS
Weinberger Hi-G 8 1.8 Yes slight vignette
Kern Switar 10 1.6 No ~14mm IC
Schneider Cinegon (silver) 10 1.8 No ~14mm IC
Schneider Cinegon (black) 10 1.8 No ~17mm IC
Schneider Cinegon 11.5 1.9 No ~15mm (rumor)
Elgeet Cine Navitar 12 1.2 No ~16mm IC
Cosmicar 12.5 1.4 Yes no
Computar 12.5 1.3 Yes no
Canon TV-16 13 1.5 No ~16mm IC
Kodak Cine Ektar 15 2.5 No no
Kodak Anastigmat 15 2.7 No ~13mm IC
Kern Switar RX 16 1.8 No no
Schneider Xenon 16 1.9 No no
Schneider Cinegon (black) 16 1.4 ~18mm IC
Sony 16 1.8 Yes no
Navitar 17 0.95 No ~16mm IC
SOM Berthiot Cinor 20 1.5 No ~16mm IC
Fujinon TV 25 0.85 Yes ~16mm IC
Angenieux Type M2 25 0.95 *arri* 95%
Angenieux Type M1 25 0.95 No 95%
Angenieux Bell&Howell 25 0.95 No no
Century 25 0.95 ~19mm IC
Soligor ITV 25 0.95 no ~19mm IC
Kern Switar 25 1.4 Yes ~18mm IC
Kern Yvar 25 2.5 No ~18mm IC
Kodak Ektar 25 1.4 corners
Pentax 25 1.4 No 16-Sep
Schneider Xenoplan 25 1.9 full>22mm
Schneider Cine Xenon 25 0.95
Schneider Xenon 25 1.4 full>22mm
Schneider Cine Xenon 25 1.4 No ~15mm IC
Schneider Cine Xenon RX 25 1.4 16:9 ~20mm
SOM Berthiot Cinor 25 1.8 No ~19mm IC
SOM Berthiot Cinor 25 1.9 No ~19mm IC
SOM Berthiot 25 0.95 Yes full
SOM Berthiot Lytar 25 1.9 No ~19mm IC
Taylor & Hobson Cooke Kinic 25 1.5 full>22mm
Taylor & Hobson Bell&Howell 25 1.9 no ~18mm IC
Taylor & Hobson Cooke Filmo 25 1.8 no full>22mm
Zeiss Tevidon 25 1.4 Yes 16:9 ~20mm
Computar 25 1.3 Yes very slight vignette
Wollensak Cine Raptar 25 1.9 no full>22mm
Kern Macro Switar 26 1.1 no slight vign
Schneider Xenon 35 2 full>22mm
Schneider Xenoplan 35 1.9 No very slight vignette
GE 36 1.1 No full
Kodak Cine Ektar 40 1.6 No full>22mm
Kern Macro Switar 50 1.4 No full>22mm
Navitar DO-5095 50 0.95 Yes full>22mm
Canon 50 1.8 No full>22mm
Kodak Cine Ektar 63 2 No full>22mm
Kern Yvar 75 2.8 No full>22mm
SOM Berthiot Cinor 75 3.5 No full>22mm
Schneider Xenar 75 2.8 full>22mm
Kern Switar 75 1.9 full>22mm
Angenieux Bell&Howell 75 2.5 No full>22mm
Wollensak Cine Velostigmat 1″ 1.9 No full
Wollensak Raptar 1″ 2.5 No full
Kern Vario Switar 18-86 2.5 No ~16mm IC

 

Now,  a vignette fx can be nice.  In fact. It’s even a preset on after effects and popular in some packages like Red Giant Magic Bullet..  it can work well on a music video but I would find it a bit awkward in a narrative piece.
Given the above table,  probably as wide as 35mm would be what most would recommend as a general safe area and a good focal length on the m43 machines (giving you an effective 75mm focal in 35mm terms, a general portrait/medium close up focal length),  you can add vignettes in post if you feel so and have full control over it.
Another thing to consider is that a typical lens design is sharper in the center and less sharp in the corners. Resolution and possible contrast drop may happen at the same time. While this can be corrected on modern lenses design,  this issue would be ever-present for any C -mount lens. Depending on the real lens you can get some corner smearing too, which again is a non removable effect. Below an example

 


This is it.  When shopping for old c-mounts bear go mind that you are not paying for full lens coverage. These days 26mm Switars are going for crazy $450 minimum,  they are indeed very fast but almost unusable wide open.
Bokeh.  Forget about creamy and smooth out of focus areas,  most of these glasses will have a swirly background..  which you might like or not.  To me it’s an interesting effect and you’re not always buying a lens because it is technically perfect, the swirl is something you would only do in post with time-consuming rotoscoping techniques or with carefully planned ahead green screen work.

 


I would recommend Kern Paillard Switars, you will be amazed how sharp these old beauties are and the color rendition. Possibly I would go with the AR versions,  the RX ones were meant to be used with a prism and might lead to potential issues.  You can go for the Yvars too,  they will be very good but the top of the line were the Switars back then, with the Pizars positioned further below at the entry-level line.  Best to avoid the zooms,  quite likely they will all porthole all along the scale or to a certain focal lengths.. unless you opt for the ETC mode but to me it’s not an option, too fuzzy, no external HDMI output and issues with some hack patches.
The 50mm Switars are going for a minimum of $500, they are very sought after.  Down to you to decide if you want to spend that money on a 30 years old lens with limited design.
There a couple more cons I would line to draw your attention to.  Namely the grease on these lenses tends to dry out so either aperture or mostly focus are stiff. Luckily enough they are self -serviceable so with some extra care you can work around this.
The other issue will be even more present and that is due to the C-mount design itself. Pretty much like the M42 design, C-mounts have to be screwed in like a bulb lamp, there is no lock so if ANY ring is stiff,  the lens will pop out.
Even if well lubed the lens might unscrew and that fact alone is a pain in the neck if you ask me.  Never mind follow focus,  put it in the wardrobe and let it collect dust.
One solution would be to glue the mount to the lens base,  adapters come really cheap so you could.  In this case a resale is quite unlikely going to happen though..

 


As a Director of Photography (or DP as it’s quite popular to say) is part of learning curve to try lenses on and I tested Kerns 3633 and 75mm, Bell & Howell 3″ Angenieux, Rank Taylor & Hobson Cookes Anastigmatic 75mm, Pentax Cosmicar 25mm and others memory might have left behind but I ended up selling them on.
Kerns were indeed intriguing. Kodak Cine Ektars are meant to be good as well and quite the same league but I cannot swear by that. Generally speaking all old 16mm Bolex stuff is worthy a look.
My personal advice is to try them on if you can find them cheap,  it can be funny or you can discover some real gems but overall I would not bother too much..  there are better alternatives out there.Even for the forthcoming smaller sensor Blackmagic cinema camera or Digital Bolex I would not find them too appealing,  I know they will be soon hunted for but I feel that ARRI PL mounted super 16mm lenses would be better performers.

3 Responses to C-mount lenses on Micro Four Thirds

  1. RolandJupiter0 RolandJupiter0 says:

    well but I have found some beautiful lenses in C-mounts, to me they are worth it !!

  2. Banana-shot Banana-shot says:

    hey why don’t you name some of those?

  3. Banana-shot Banana-shot says:

    I really could see myself with a nice Blackmagic Camera and some vintage C-mounts, 12db of dynamic range dressed in a vintage outfit..

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