The first two images were made with a Lytar SOM Berthiot 25/1.8. I think these images are indicative of what is appealing about shooting with c-mount lenses. Note the vignetting, the color saturation, and the smooth bokeh that has a tendency to get 'swirly' in busy areas.
The vignetting is a result of the focal length. Wider focal lengths seem to produce the strongest vignetting, and the 25mm focal length seems to offer a nice trade-off.
The Lytar SOM Berthiot 16/2.8 vignettes pretty fiercely (sample below). I've also shot with a Wollensak 17/2.5 that produced similar results. The vignette look of both lenses lenses has a 'tunnel vision' effect. I've not played much with either lens to be able to discern whether the lenses offer or add much value within the image area. I've seen wider lenses that offer a distinct fish-eye effect.
I'm not finding much value in the 'tunnel vision' effect. I prefer the coverage, and, going forward, I'll probably avoid any c-mount lens wider than 25mm or 20mm.
Here's the Lytar 16/2.8.
Noting the flare, I think the lens might have some fungus or lens damage. I haven't been able to determine the condition. The lens elements are very small and the front side is deeply set within the lens, so I haven't been able to evaluate the condition nor confirm that my cleaning is thorough enough. However, this is an improvement from the first few shots with the lens.
The next images were made with the Kodak Ektar Cine 63/2 lens (more images available in an earlier post). Notice the lack of vignetting.
This is an interesting lens. It's pretty sharp and the bokeh is rather nice. It's an all-metal lens with a length around 3.75 inches (less the hood and including the removable s-to-c-mounting), but the weight is very manageable on my G1. The lens has eight blades, and the close-focus marking on the lens is 24 inches. I'm thinking this lens can probably be had at auction for cheap, so if you would like to try a fast longer lens in a c-mount, keep your eye out for this one.
