| I don't think distortions from the glass would be an issue so much as the internal reflections. And the dust and fingerprints. There is plenty of depth of field at the paper end of things with the lens stopped down to f11 (50mm) so the paper doesn't have to be perfectly flat - glass isn't a requirement for a sharp image.
I do a fair bit of borderless printing and it isn't any big deal: you can buy a borderless easel on ebay for not much money; make a vacuum easel out of an old graphic-arts camera back (google for DIY vacuum easels); use a low-tack adhesive and a scrap bit of laminate; place strips of refrigerator-style plastic magnet on a cookie tin; just lay the paper on the baseboard; or trim the borders off after you make the print. |