Digital BW, The Print

on 9/6/2002 9:45 PM, DigitalBlackandWhiteThePrint@yahoogroups.com at
DigitalBlackandWhiteThePrint@yahoogroups.com wrote:

> Message: 5
> Date: Fri, 6 Sep 2002 22:43:30 -0400
> From: "Austin Franklin" <darkroom@...>
> Subject: RE: Re: Shooting digital vs. film
> 
>>> Well, I'd argue that it's really diffuse...it's still point
>> light...simply
>>> putting a diffuser over a point light source doesn't make it a
>> diffuse light
>>> source in the traditional sense, like a cold light...does it?
>> 
>> diffuse is diffuse. That said the size of the light source will
>> make a large
>> difference.  If you make a very small diffuse source, it will act almost
>> like a point source or lens focused lamp.
> 
> Well, I still say diffuse isn't necessarily diffuse.  Diffuse, as far as a
> light source for film projection goes, MUST give a completely even field
> over the entire field, and I do not believe the LEDs of the Nikon scanner do
> such.  I do know that my cold light heads do, and that the light source on
> my Leafscan does too.
> 
> If diffuse was diffuse, with respect to this subject, then a single
> incandescent light bulb would be diffuse by your definition.
> 
> Austin

Austin,

That's right, a single incandescent light bulb (frosted of course!) is
diffuse.  However, projecting a shadow from an object 5 feet away on a wall
10 feet away will show that a 2inch diameter bulb is a lot less diffuse than
a 6 foot diameter bulb when casting the same shadow from the same distance.

Therefore: in a scanner the SIZE of the light source matters, and the
DISTANCE to the film  matter as well. And the quality of the taking lens as
well.  I'm not writing good English here, I hope I'm making sense.
 
-Bruce

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