Re: [APML]: Digitizing Slides. Help!

[Steve Bell <sb635@delphi.com>]

Chuck Vaughn wrote:

> That's why you want to use a slide scanner for transparencies instead of
> a flatbed scanner. The slide (or negative) scanner shines light through
> the silde and onto the CCD.
> 

I'm a relative noivice at negative digitizing, but I have dealt with alot of computer 
graphics through the 
years, and this is what I do with my Microtek ScanMaker 35t. First, I develop the 2415 
negative and hope that 
the sky fogging is not too severe. Even if it is, I always give it a shot. Using the 
scanner (which is actually 
another CCD camera (for the most part) that we can use) I scan in the negative (it's a 
SCSI device) into Sft'wr 
Bisque's SkyPo.  The software allows an auto contrast adjustment, and I allow this. 
Sometimes it does a pretty 
good job. Most of the time, I adjust the shadow setting so that the sky appears 
relatively black.  You can do 
all this in a pre-scan, and when I get a good image in a cropped box around the object, I 
then do an actual 
scan.  The image comes into SkyPro as 8-bit 256 greyscale, and if acceptable (usually is) 
I save as a TIF file. 
 This file is usally ~ 1-2 megs big. I scan in at different resolutions, but I always 
create the TIF file at 
least 300 dpi - if the crop is around a small part of the 35mm frame, I may bump it up to 
600 dpi.  For 
something as small as M57 (Ring) I might use 1000 dpi.

SkyPro allows saving in just about any format, and I've found that converting the TIF to 
24 bit True RGB color 
helps what Netscape will show on the net.  I've tested this out on both PC and Mac 
systems of various 
capabilities, and I know that Netscape (or a functional equivalent) selects the best 
image viewer (will select 
the 24 bit viewer, if your machine can do it). After conversion to 24-bit RGB, I save the 
file in JPG format 
usually using a compression of 15-20 to get the file size down to 100k or so. I find that 
even at my slow 14.4 
modem rate, I can stand the minute or so wait to see an image.  Using the direct Internet 
(ethernet) 
connections at work, these images appear in just a few seconds.

-- 
Clear skies,
Steve Bell
sb635@delphi.com
http://people.delphi.com/sb635 - Astrophoto page