For example, I have an M-mount adapter and an F-mount adapter for my Panasonic Lumix G1. Those adapters allow me to attach Leica and Nikon-compatible lenses (respectively) to the camera. I recently acquired a C-mount adapter ($20 off eBay). This adapter allows me to attach and shoot with cine and CCTV lenses.
I probably wouldn't have bothered with the C-mount adapter if I didn't already have a Bolex 16mm camera with three C-mount lenses sticking to the front of it. I'm glad I did bother, because for me the adapter has opened up a new world of exciting optical possibilities .
The photos below show my Bolex camera with two of the three lenses attached. I'm shooting with the third lens, a Kodak Ektar Cine 63/2.
The other lenses are Lytar SOM Berthiots. One is a 25/1.8 and the other is a 16/2.8.
There are a lot of C-mount lenses out there (both new and used/older)—many with names I've never heard or with names that I haven't heard mentioned in over 20 years. While I'm just beginning to understand the characteristics of these lenses on my m4/3 system, one of the things I've noticed is C-mount lenses are fast. Generally, most of the lenses I've come across in my online viewing and research land in the f0.95 - f2.8 range. I'm sure there are slower C-mount lenses, but it's the lenses in this range that are creating a stir.
From what I've seen, the quality of these lenses can run the gamut from Holga-ish to Leica- and Zeiss-like. The results have been impressive.The effects range from images with heavy vignetting and flare-y softness to 3D-like images with creamy smooth bokeh supporting razor-sharp in-focus areas. Images with seemingly impossible DoF shifts and images with spot color saturation are not uncommon either.
The photographic world pretty much caught on to the c-mount rage a while ago, so if you're looking to pick up a couple of these lenses, you can expect to pay a premium or engage in some heavy bidding wars. Regardless, as of this writing, the lenses are still a bargain compared to what you might pay for fast lenses in other mounts. However, as I stated above, there are a lot of these lenses out there, so there are also a lot of unknowns. Do your research and know what you're getting. It can be difficult to assess what you can expect from a C-mount lens on a mirror-less system. This is where a service such as Flickr is invaluable. The site has groups dedicated to C-mount lenses, and it's in these groups where you can find the image samples you need to help you make a decision. You can leverage the efforts of those brave souls who venture into the unknown and scoop up some no-name CCTV lens.
If you are going this route, remember that mirror-less systems have a crop factor. In the case of the m4/3 the crop factor is 2x. A lot of the current samples in online groups are 25mm lenses.
If you're interested in checking out some images created with C-mount lenses, then I recommend starting at the Flickr group, C-Mount on Micro 4/3. And once you get to shooting with your C-mount lens, do us all a favor and share your results.
