Re: [APML]: Digitizing Slides. Help!

["Mark C. Taylor" <mct@interramp.com>]

At 09:43 PM 9/3/96 -0700, Howard C. Anderson wrote:
>I have some slides of various deep-sky objects and would like to
>have them digitized so I can put them on my home-page.

Well, this may fly in the face of conventional wisdom, but these are my
thoughts and plans...

First, IMHO, slides were meant to be viewed by projecting light *through* 
them.  The problem with scanner-based solutions place the slide with
a white surface behind them, shine light on the *front* of them, and then
take a picture of the resulting (dim) image.  This seems all wrong to me,
and is why you have to tweak the resulting images.

I own a "Snappy" (although probably any video frame grabber may do the 
same job).  I plan to project the slides onto a screen as they were meant 
to be seen, then use my camcorder and Snappy to grab a live video frame.

I know what you're thinking - video resolution is lame.  However, Snappy 
grabs better MUCH better detail from live video (no snow/crackle) and it
takes 8 images and basically does some software based "image stacking" 
to get a whopping ~1500x1200x256 image.  It also uses the data from the 
horizontal refresh area to get good color balance, etc. (a bunch of 
video-techie details I don't know about ;^)

That may be lower resolution than you would want to make prints
from, but it is *overkill* for what most people post on a websites.

Another benefit to Snappy is that it will read an input image as B/W or
color, and will read it as a positive or negative image.  So theoretically
you could mount all of your film in slides and use this method to transfer
them to graphics.  Or if your videocam focusses close enough (like mine), 
you could put negatives on a backlit display and take the images right
from the 35mm film (although I expect this will yield less detail).

The best benefit to Snappy is that it's less than $100 (assuming you
already have a decent camcorder) and comes with some image whacking 
software (albeit low-tech stuff).


I just decided to start using slide film from now on, and plan to go
through this process over the next few weeks.  When images are ready, 
I'll make them available for all to critique the image quality (but NOT
the photo quality ;^)

Regards,
---------------------------------------
Mark C. Taylor       mct@interramp.com
Software Engineer / Amateur Astronomer
Sunnyvale, CA   37:20:54N x 122:01:56W