Re: condenser optics??

From: 40 Frames Directory (email suppressed)
Date: Wed Jan 04 2006 - 09:40:05 PST

>> Seems to me like the
>> foil/filament could be designed in such a way as to direct light that
>> with
>> the aid of the reflector would focus to a finer point
> What you want is the light more or less parallel I think. The lens does
> the 'focussing to a point' so to speak.
> The real problem with 16mm projection is edge to edge sharpness and
> portholing.
> (measure screen brightness with a spot meter sometime, see what happens
> the further you get off the center)
> -Sam

Edge to edge sharpness is indeed a big issue. I've seen amazing results
with the ISCO Kiptaron 20-60 and Schneider Cinelux fixed focal lenses. Of
course, you get what you pay for and these lenses fetch a handsome price.

I have several of the cheaper ISCO Vario-Kiptaron 35-65, which I think are
a vast improvement over Buhl, Kowa, Eiki, etc. In a small space I see the
difference. Our screen is a mere 8' x 6' (matted). So edge to edge
sharpness is not difficult to achieve. IMO small spaces and cheaper lenses
work ok, it's when you go to auditoriums with big screens that higher
quality lenses make a difference.


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