Ken Watson (watsok@frii.com)
Mon, 25 Jan 1999 13:44:34 -0700
There are scanners that have the ability to "scan" a projected image.
However this is not common today. If you just want to scan the negative one
needs to build a 90 degree reflector out of mirrors that would set behind/
on top of the negative ( Scanners are reflective devices) so that you get
some light through the negative / transparency. One of the issues is that
the reflector should be a front surface mirror and slightly convex. This is
to de-focus any artifacts in the illumination. The 90 degree mirror should
be 2X the size of what is being scanned. If you think about this you realize
that the file is getting the same illumination from the back as it is from
the front by reflecting the scanners light to the rear of your film. An
alternative to the convex mirror would be a diffuser of some sort. One needs
to be careful as the depth of field on some scanners is quite deep and you
may introduce artifacts from your diffuser
> -----Original Message-----
> From: William J. Thomas [mailto:bthomas3@jps.net]
> Sent: Monday, January 25, 1999 1:33 PM
> To: alt_photo
> Subject: re: scanning 4x5 negatives ?
>
>
> being new to this group and digital (darkroom guy), i am looking for a
> way to scan 4x5inch and 6x9cm negatives.
> and being able to print at 400 dpi. if i have the math correct on a
> 4x5 i need to scan at 1600 dpi (optical) to print a 16x20
> (400*16/4). can i use a 600 dpi scanner by projecting the 4x5 negative
> to 10.7x13.4 onto the face plate of the scanner
> (400*16/10.7)? has anyone done this?
>
> does anyone know where i could get software which can deal with a
> negative and its orange mask?
>
>
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:06:47