Scanning Glass Plate Negatives

[paulr]

Epson scanners are designed with the focal plain 1mm above the glass. The depth of field is deep enough that originals placed on the glass are quite sharp. Raising a glass neg will let you hit the actual point of focus, and at the same time help you avoid newtons rings and scratches on the document glass.

There seems to be a lot of sample-to-sample variation when it comes to the exact plane of focus. It can range from 0mm to almost 3mm above the glass.

You can make a mask, as Jim suggested, but instead of using 2-ply matboard you can use thinner stock, and make several. Experiment with the number of layers to use until you find the sharpest point of focus. Remember to leave a cutout for the calibration area.

Any epson scanner later than the 3200 will produce extremely sharp scans from a flat large format neg. The 4990 will scan 8x10.

[John Flavell]

Dave, those look great. I like the portrait from behind, and I really like the riverboat since my work area is near the Ohio River, up river from Cincy.

On the other hand, I'm a long-term thinker at this kind of project. Do a community service thing for the library, then look to other uses. I may just have a use for that 4990 myself since I have over a hundred 4x5 negs to scan. I'm just trying to be "efficient". I'm looking through all the reviews of this new beast and I'll decide soon.

The good news is that all the galleries suggested by everyone shows how good this could be.

Thanks again to all.