Here are two more c-mounts. I like the Canon 25/1.4 on the m4/3 format, it has a great handling, the IQ is nice, the size is perfect, and the sensor coverage is decent, i.e. slight vignetting but less than e.g. a Kern Switar. The lens is in good shape, it has been sitting around for a while and would benefit from a good cleaning, though... I can add a rear cap but don't have a front cap for it. $149 incl shipping, insurance & paypal.

_1080535 by mgapicius, on Flickr

_1080531 by mgapicius, on Flickr

Here is a pic taken with it, fully open on a gloomy day in 16:9 format

Canon TV-16 25/1.4 at f1.4; 16:9 format by mgapicius, on Flickr

The Canon 13/1.5 is a decent cheap wide angle for the m4/3 system. Like most wide c-mounts it does vignette and the sharpness falls off toward the corners. But it is usable, especially in 1:1 format, and being fast as it is, I like having one of them around (I have more than one of these...). This copy here is a mixed bag: The outside and barrel show signs of use but nothing that is worrisome, the glass is also good, I can see no major flaws. However, some of the inside paint seems to be bubbling up a bit (see second picture). This does not affect the IQ in any way that I am aware of, and it seems to be similar with all the copies I have, so I assume that is a design flaw. Low price on this one, $89 shipped & paypaled in the US. Comes with a case, no caps.

_1080513 by mgapicius, on Flickr

_1080509 by mgapicius, on Flickr

Here is a pic with it in 16:9 format. Obviously, the vignetting will be much less in 1:1