WAKD Loc: Cincinnati

ALL of what GoofyNewfie says is the way it is. You may find that placeing a black sheet on you copy surface will help you track down 'mystery' reflections.
The only thing I might add is that a vacuum platen may be of use. Don't need expensive, a decent DIY rig would work.

And try to limit light spill. Only what you are copyiing needs lisht!

PHIL BITTLE Loc: CALIFORNIA

First - Do not lay flat. The book should be verticle even if it means building (or having built) and frame to hold the book(s). Make sure your glass is "water white", i. e. no color, and that the frame holds the glass firmly against the material to be copied. Also, make sure that the frame and camera are perfectly lined up, parallel.

Light Evenly - Use four lights of equal lumens (brightness) and color temperature, one for each corner, far enough back so to use the relative center of the circle of light, i. e. avoid lighting the books with the edge of the light.

Check Lighting - Using an Incident Light Meter, check the reading at nine different points. TOP LEFT CORNER. TOP MIDDLE. TOP RIGHT CORNER / CENTER LEFT SIDE, CENTER MIDDLE, CENTER RIGHT SIDE / BOTTOM LEFT CORNER, BOTTOM MIDDLE, BOTTOM RIGHT CORNER. Make sure they're of equal brightness. Then move the meter around to see if you find any fluctuation ... if so, adjust until all areas are equal.

Make Exposure - Use a lens with a FLAT FIELD OF FOCUS. Using a gray scale, photograph gray scale at each f/stop, select best exposure. Once you've determined your exposure, make a series of developing tests @ one minute intervals ... select proper developing time. You want to see gradations as per the gray scale.

You want your copy room to be dark in color and illumination, no more light than necessary and NO SHINY SURFACES from equipment or anything else.

Finally, shoot from BEHIND a dark surface ... this could be a large piece of non-reflective, black cloth, large enough so that the lens, poking through a slit or hole in the cloth can only see the copy material.

Those steps will take care of your problem. You don't need non-glare glass as there's nothing to reflect.

the f/stops here Loc: New Mexico

Been there and done that ... the black cloth or board works best. The polarizing filter will help saturate colors but will not handle the glass reflection problem.

JonZ

45º often isn't enough. Move your lights as much as 30º off the subject plane (and/or further away) and aim the axis of the light at the far edge of the subject. As said, go for the longest lens practical. I've shot scads of artwork both under glass and without and have never had to put up with reflections of lights or stands. While your at it, rig a mirror and string so you can hang the mirror in front of the center of the art. Center the reflection of your cameras lens in the center of your viewfinder to eliminate perspective distortion.

Scott Gottschall Loc: West Jordan, UT

I've never tried your method for photographing old books. I use a method that is listed here: http://www.subchaser.org/photographing-documents

I, in my love for family history, come across a variety of documents and photos. Scanning is best if the pictures or documents are small enough. Otherwise, I have brought my old Canon Rebel G film camera and used it very similar to the article listed above and get the pictures developed and printed so I can scan them in.

Larryw918 Loc: Tulsa, Oklahoma

I was in the microfilm business for many years and have filmed the Cherokee Indian roll books and Hernando DeSoto's log books from the 1500's. You need to do it a room that is painted flat black, copy stand lights at a 45 degree angle, using photo flood lamps, two on each side. Try that and see how it works for you.

HLS45 Loc: Fairmont, WV

Many years ago, I copied about 450 pages of a book I wrote, to create slides. I used frosted glass I got from a glass shop. There was no reflection.

alliebess Loc: suburban Philadelphia

I've used the frosted glass, but believe that I lost some sharpness as a result.

Shutter Bugger

That's right... all you have to do is move the light source.