12-13-2010, 06:54 AM
Do I still have the same lens focal length if I put the lenses onto the B4 to PL to a varicam?
So 18mm will stay 18mm. Or is a 35mm adapter needed for that matter
12-13-2010, 12:58 PM
Your focal length is the same, and retains the same optical properties, no matter which camera you mount it to.
Super 35mm lenses most commonly come with a PL mount.
B4 mount is the mount used by 2/3" video cameras.
So, you'd have to convert an 18mm PL mount film lens to B4 mount if you wanted a direct attachment. That would be a mechanical adapter of some sort. (and I don't know if its possible to directly adapt a PL mount to B4)
So... on to your real question: will the field of view be the same on a B4 type camera as on a RED or other S35 camera?
The field of view refers to what the lens "sees", and is usually represented with angular measurements.
No. On a B4 mount camera any given lens will be significantly cropped compared to a 35mm sensor.
The 18mm lens is in the middle of the zoom range of most b4 camera lenses.
The wide end of most B4 zooms is usually near 6mm.
If you want to retain the look and frame size that you get with a RED on the B4 camera, then you need an optical 35mm to B4 adaptor. Something like this:
Letus sells a much less costly adapter for this purpose. You can buy a Letus Elite adapter with a PL mount and a 2/3" relay lens to connect to the B4 camera. You can then attach the Letus to the relay lens and get the same results you would normally get on a S35 cinema camera.
The cost for such a set up from Letus starts around $6000. (That adapter is about $1500 and the relay lens is about $4500)
Hope that helps.
12-14-2010, 12:35 PM
That helps a lot. Very clear explanation thanks.