Apache-Talk @lexa.ru 

Inet-Admins @info.east.ru 

Filmscanners @halftone.co.uk 

Security-alerts @yandex-team.ru 

nginx-ru @sysoev.ru 

   


   


   















      :: Filmscanners
Filmscanners mailing list archive (filmscanners@halftone.co.uk)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: filmscanners: LED Illumination for Film Scanners



Moreno wrote:
>And taking things one step further, a dense LED array positioned closer to 
>the negative could even be
programmed to provide some degree of selective dodging/burning/variable
constrast control. With an appropriate control mechanism, a user could
adjust for dead even lighting across the easel for a specific lens/format
size combination.

This is a very signifficant "AhHa!" IME. I'm actually surprised that no 
programs, to date, are using that possibility. As I might have said sometime 
ago, we users *do* have some ideas worth considering, from  time to time. 
;-)

Best regards--LRA


>From: "Moreno Polloni" <mp@dccnet.com>
>Reply-To: filmscanners@halftone.co.uk
>To: <filmscanners@halftone.co.uk>
>Subject: Re: filmscanners: LED Illumination for Film Scanners
>Date: Wed, 20 Jun 2001 15:05:09 -0700
>
> > > A couple of years ago someone on the darkroom newsgroup was working on
>an
> > > LED light source for enlarger heads, utilizing clusters of
>high-intensity
> > > LED's. I don't know what happened to the project, but at the time a 
>lot
>of
> > > people were really excited about the technology and the initial 
>results
> > > showed a lot of promise.
> > >
> > > http://www.trailing-edge.com/www/led.html
> >
> > Yes, and look at how uneven the lighting is.
>
>Quoting a recent post on this list: "And you can tell this from a 72dpi 
>JPEG
>image?"
>
> > For an enlarger, that may turn
> > out to be a very bad idea, simply because you can't adjust each 
>individual
> > LED for even illumination.  At least with a CCD, you can adjust the gain
>for
> > each sensor element to get even illumination.
>
>Why can't you adjust each LED for illumination levels? For instance, the
>designer could quite easily vary the voltage levels throughout the array to
>compensate for enlarger lens light fall-off. And taking things one step
>further, a dense LED array positioned closer to the negative could even be
>programmed to provide some degree of selective dodging/burning/variable
>constrast control. With an appropriate control mechanism, a user could
>adjust for dead even lighting across the easel for a specific lens/format
>size combination.
>

_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com




 




Copyright © Lexa Software, 1996-2009.