The Nikon 1 cameras – J1, J2, J3, J4, V1, V2, and V3 – use a “1 inch” sensor that is about the same size as “Super 16mm” film. The small’ish sensor is ideal for working with old 16mm lenses (I have one) or with various c-mount lenses. Ideally, the c-mount lens should provide a “1 inch” coverage. However, the photos below were shot using a Tamron 4-12mm f/1.2 lens having a 1/2 inch coverage. Except when zoomed in, in which case it covers the full frame with a very tiny amount of vignetting.
These macro photos amazed me – shot on an inexpensive Nikon 1 J2 with a CCTV c-mount lens! You can click on the photos for larger version, although these were uploaded at about half the horizontal resolution. The extremely narrow depth of field is pretty neat for a small sensor camera using an inexpensive wide angle lens!
The c-mount lenses I have used are often quite soft when the aperture is fully opened. Stopping the aperture down a bit improves sharpness. They also tend to have softness in the corners, or vignetting. This particular lens is very good for these close macro shots – the edge softness is obviously not a problem as it is supposed to be out of focus! But I would not recommend this lens for general purpose shooting of non-close subjects. I also have a Computer 12.5-75mm f/1.2 lens. This is useful mostly in full zoom (75mm end) but at f/1.2 it is very soft. Stopping it down to f/2 to f/4 greatly improves the image quality – and with the telephoto effect, does a good job for creating certain types of narrow depth of field. I would not use it as a general purpose lens, however.