Computar f/1.2 12-75mm c-mount lens on Nikon 1 J2 camera

I recently acquired a used Nikon 1 J1 and a Nikon 1 J2 camera for use in my 3D photography and 3D video photography. I also bought a used Computar f/1.2 12-75mm c-mount lens, originally intended for us on “Super 16mm” film cameras. These can be adapted well for use on the Nikon 1 mirrorless cameras as the sensor is essentially the same size as a “Super 16mm” frame.

Here is what the lens looks like – it has a 55mm filter diameter but came with a 55 to 58mm step up ring:


At wide angle (12mm) and telephoto (75mm), there is minimal vignetting. At some of the in between range, there is very noticeable vignetting.

To make the lens work on a Nikon 1, I used a Fotodiox c-mount to Nikon 1 adapter ring. I quickly found this ring puts the lens too far forward from the sensor focus plane. I ended up using a Dremel cutting bit on my shop drill and did a lot of grinding to push the lens almost 1/8″ of inch deeper into the camera. (Later I bought a different and thinner adapter ring that seems to work without modifications but I have not yet done much testing with this adapter ring.)

Here are some results – shot using the Computer f/1.2 12-75mm cine lens on a Nikon 1 J2 using a modified Fotodiox adapter. All images were shot in RAW mode and contrast or exposure adjusted slightly in Lightroom. The first photo used the “anti-vignetting” feature to lighten the upper left and right corners slightly. None of the photos are cropped. All photos are shot with the camera in full manual exposure mode.



The focus point on this handheld shot is the pond frond located just to the right of center.  At f/1.2, the depth of field is so narrow that none of the other plants are actually in focus!

This last photo was intended to test deep focus. However, when shot at f/1.2, the depth of field was still so shallow that te actual focus point ended up being near the back of the trees in the background. I need to go do more tests on the infinity focus but I am not too worried about infinity focus since I do not expect to use the lens for that type of shot. Plus stopping down just a little expands the depth of field.


Overall, I am very pleased with the c-mount lens and Nikon 1 combination. The J1 and J2 do not have electronic viewfinders – only LCD back panels. For 3D shooting, that is fine as I want to see both cameras at the same time. However, if I were to use the Nikon 1 for 2D still shooting, I would probably prefer the V1, V2 or the said to be coming soon, V3 cameras. The V series is like the J series but with EVF and hot shoe, and slightly larger body.

It is amazing to be able to shoot photos like this with such a tiny camera and lens combination compared to shooting FF cameras. I prefer small cameras. Since I mostly shoot 3D, I am often carrying 2 or 3 pairs of cameras and the weight gets old after a while!

For more examples of what c-mount lenses can do for mirrorless cameras, check out this web site. Once upon a time, c-mount lenses were very inexpensive. But since the popularity of mirrorless cameras – micro 4/3ds, Nikon 1, Sony NEX and the Blackmagic Cinema pocket camera (4k video!) – the market for c-mount lenses has taken off. Bargains are tougher to find now but they can be found if patient. Still, a $100-$200 c-mount lens is a lot cheaper than a new $1500 m43 lens that does about the same thing 🙂

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