TV zoom lens
G . Stephen Bruno
Posted 11 December 2005 - 09:01 AM
Posted 11 December 2005 - 10:37 AM
i am looking for a c-mount to go with my 16mm auricon. On ebay i have found several "TV zoom" lenses. What is the difference with these lenses? Will they work on my camera? I ask because when i read the words TV zoom, i imeditialy assume that they are for a studio video camera,
I suspect most of these are for use on old B & W non broadcast standard TV cameras or CCTV. With the Auricon you need a zoom lens with a built in viewfinder. The Auricon is a non reflex camera like the early CP16s. A commonly used lens is the 12mm to 120mm Angenieux, but there are other makes with a built viewfinder.
The TV zoom lenses were intended to be used on B & W TV cameras, so wouldn't have the same standard of correction as the film camera lenses, which were used to shoot colour.
Posted 11 December 2005 - 12:52 PM
i am looking for a c-mount to go with my 16mm auricon. ...
Brian is correct, you need a lens with a side viewfinder built in for use on a non-reflex camera such as Auricon.
For use on other reflex type cameras there are a few things to watch out for:
Generally the 12-50mm and 16-64mm zooms were made for a 2/3" (outside diameter) size Vidicon and will not quite cover the 16mm movie frame. That is, you will get dark corners at some focus or zoom settings.
Generally the 20-100mm zooms were made for a 1" size Vidicon and will cover the 16mm frame and may even cover super-16.
Zooms shorter than 12-50mm are probably CS mount instead of C mount. Although the threads are the same, these lenses will not focus on a 16mm camera as they need to be 5mm closer to the film. Also they will not cover the whole frame even if you modified them to focus.
Sharpness will not be up to the very best film lenses.
The footage may come out 1/2 to 1 stop underexposed. TV lenses are calibrated strictly geometrically while film zoom lenses that I have used do make an allowance for light losses (except at maximum aperture) even if they are officially marked in F stops instead of T stops.
i am looking for a c-mount to go with my 16mm ...
I forgot to mention, do NOT get a TV zoom lens with electronically controlled aperture. These are totally incompatible with a film camera. Even if you jerry-rig an external box to get the iris to open up, there will be no indication of what F stop you are at, and so forth.
G . Stephen Bruno
Posted 11 December 2005 - 02:16 PM
Posted 11 December 2005 - 04:19 PM
Wow, thanks for the replys fellas. Yeah, I know i need a lens with a reflex side finder, i was just wondering what these "TVZOOMS" were about, thanks alot Brian. Do you have any recomendations on where to find a c-mount lens w/reflex finder (older preferably) I have been searching, but i can't find one online, well, not with a pic to show what it looks like anyway.
These lenses are going to be old. I expect you'll find the odd one coming up on e-bay, however you really want to see the lens before buying it. You could check second hand camera shops in places like New York and LA and let them know you're interested in one of these lenses. Some of these specialize in older 16mm cameras. You could put an ad in some web sites.
Posted 11 December 2005 - 04:53 PM