Scanning glass negatives

[Sylvester Graham]

I'm sure this must have been discussed before. Thanks for any links. A search for the term didn't turn up much, since "scanning," "glass," and "negative" come up pretty frequently here.

In any case, I recently scanned a 4X5 glass in using my 750. I put the emulsion side down, but came up with quite a few weird colored scan lines. I had chosen "set scan area" instead of "with filmholder." I flipped the neg and the lines were gone, but now it seemed a little blurry. What's proper protocol for scanning a glass neg?

Thank you

[jp]

I put the film area guide down, then the negative. I use a penny or other small spacer object to keep it from being glass-glass contact (and resulting newton rings).

[jnantz]

hi amline

i've scanned glass plates on and off since i got my first scanner in the 90s ..
i never had trouble with newtons rings and just put the glass plate directly on the skanner-glass .
sometimes if the plate was thin enough i didn't need the transparency lid to light up ( a white piece of paper worked well )
sometimes they were dense and i needed the extra light.

good luck !
john

[benrains]

As someone else stated, the patterns you see are probably Newton's rings. When I'm scanning sheet film, as you tried with the glass plates, I scan emulsion side down to minimize their effects. My thinking has been that the metallic silver deposits on the emulsion side prevent the film base-to-glass surfaces meeting. The Newton rings still often show up in the thinner areas of the negative. With your glass though, because of the rigidity of glass, the idea of using a spacer to keep the emulsion surface lifted up from the glass is a good idea. I don't know that I'd use something as thick as a penny, but you should be able to take four pieces of paper--even something as thin as cheap copier or printer paper--and place it under each corner of the negative.

If you scan through the non-emulsion side, I'd guess it's blurry because of the glass distorting the image or it's could be because the scanner isn't focusing correctly on the emulsion. The image in the emulsion will be suspended on the "top" of the glass a few fractions of an inch above the surface of the scanner's glass bed.

[jnantz]

you could probably use clear plastic report cover sleeves
to raise the plate off of the glass if you get newton rings.
they are pretty rigid and thin and you can cut the plastic
with regular scissors... ( and increase the thickness as needed )

[sanking]

Amilne,

If you have the 4X5 film holders that came with the Epson V750 you might be able to just place the glass plate in the holder. If it fits, put it in emulsion side down. The film holder will position the plate over the glass at about the right plane of focus, if you select "film holder", not "film area guide". I tried this with a glass plate and my film holder for the V700 and the plate fit fine in the holder.

The reason for the weird color streaks is Newton Rings. Sometimes it is possible to scan negatives by just putting them direction on the glass emulsion side down, but often this will cause Newton rings. In any event, putting the emulsion right on the glass is not the right place for it to be in terms of plane of focus.

As someone else also suggested, you could just place some shims, say thin washers, or a dime, underneath the corners of the glass plate and scan with it emulsion side down. In this case, select film area guide to assure that focus is as good as possible.

Sandy

[Jim Noel]

I use the glass-less negative holder in my Microtek i900. Perfect scans every time w/o the interference of another piece of glass.

[Sylvester Graham]

Thanks everyone. Good stuff, as usual.