Anyone try 16mm cine lens with a DOF adapter ? They are made to use with follow focus and its easy to do it correctly. And you can find somes used that not too expensive. Less DOF then a 35mm, but still better than 35mm still camera lens, i guess.

16mm lenses do not have any different DoF than 35mm lenses of the same focal length; they are however designed to cover a smaller image area so they will vignette when used with a 35mm adaptor even if the lens mounts are the same.

The important thing to understand about lenses is that a 20mm focal length has the same depth of field characteristic no matter what its application. In other words, a 20mm lens on a 35mm camera system delivers the same depth of field as the 20mm setting on your DV camera's lens. However, the field of view is much smaller (i.e. more telephoto) on the DV camera for that same focal length, because the imager is much smaller.

DOF also has to do with the image target size. The 16mm film plane is much smaller than the 35mm film plane, so the circles of confusion are smaller, hence, more DOF (not Less. Less means more stuff out of focus!). a 1/3 CCD camera, like XL2, is much smaller that a 16mm image plane (1/3 inch = about 7-8 mm). Therefore, an 8mm film camera has about the same DOF (and funnily enough, resolution) as a 1/3 CCD camera.

But yes, a 20mm lens is always 20mm. However, on a 16mm camera, 20 mm lens seems to be doubled due to the image size, so if looking for a 50mm aesthetic on a 16mm camera, I believe you use a 25mm lens.

DOF also has to do with the image target size.

Indeed, that's what I was referring to when I said "the imager is much smaller".

But yes, a 20mm lens is always 20mm. However, on a 16mm camera, 20 mm lens seems to be doubled due to the image size, so if looking for a 50mm aesthetic on a 16mm camera, I believe you use a 25mm lens.

aesthetic? If you mean field of view, aka angle of view, then, yes. If you mean DOF, then, no.

Indeed, that's what I was referring to when I said "the imager is much smaller".

Those links should help make this thing clear:
http://en.wikipedia.org/wiki/Circle_of_confusion
http://en.wikipedia.org/wiki/Depth_of_field
http://en.wikipedia.org/wiki/Hyperfocal_distance

if you look at the formulas, you'll see that image plane's linear dimension(for example diagonal) has linear relation to Distance_far - Distance_near.

Bill, that is what I meant.

I could use some coffee ;)