Did you try a polarizer filter?

The polarizer works well on some reflections, but not others. Doesn't seem to do much on non-specular reflections from glass.

Well, the polarizer works if the lights are shining from positions where the polararizer can work. The stars have to line up, ya know?

A soft light would seem to offer more chances for reflections off the glass-the effect might look a little more like fogging.

Treat these as if you were shooting into something like a mirror. Keep moving those lights to the side until you can't see their reflection. Black out everything in front of the glass- you might even resort to shooting through a hole in your duvatyne or black foam core.

It'll work, you just have to keep trying.

Rob Mack

Get some sheets of polarizing gel and put those over your lights. Make sure it's oriented the same way on both lights. That'll polarize the light going to the pictures. Then use your polarizing filter to cancel out the light reflections, and you should have completely reflection-free images (well, at least there will be no reflection from your light sources).

Here's a great trick for this kind of situation -

to get you in the right frame of mind, think Pool Table Bank Shot.

1-Put a small light right in FRONT of the lens, pointing at the offending framed photograph.
2- Walk around the photo.
3- Where ever you DON'T see a reflection - that's where to put your light.
Generally speaking two lights at 45 degees is the basic setup. Use spots at full flood for even distribution. If this a a critical job, put a large grey card in front of the photo and use your Zebras at 75 or 80 IRE - not for exposure, but to see how evenly you've lit the surface. Stop down until you see the zebra's and move the lights in or out to even the illumination. Then go back to Number one for final placement.
If you are getting paid for this job, inform your client that the correct way to proceed is to remove the glass prior to shooting. This would be a billable expense.
Different glass will have different waves in it, so you will have to adjust your lights for each setup. Also, if the framer used "Non-reflex" glass - there is no way you will get a good shot.
Hope this helps...
v

Non-reflex, or non-glare glass simply means you get a light even reflection/glare form any angle all the time. Horrid stuff! Robs the image of contrast terribly. If you encounter this you absolutely must remove the image from the glass or it's not even worth trying.

Thanks everyone. I'm going to start this tonight.

All good advice but missing one important point: if you center the camera over the picture, so as to eliminate any perspective distortion, you'll get a reflection of the camera off the glass and centered in the picture. One technique that worked well for me in shooting Daguerreotypes, which, if you don't know are highly polished metal that acts as a very efficient mirror, has been to cut a circular hole in a black mat board to fit over the lens. The board needs to be large enough to cover the field of view of the lens at twice the distance from lens to picture. that way anything not blocked by the board will not be reflected into the lens' field of view. Make sure that there's no stray light illuminating the hole or lens, use gobos to shield them from the luminaries. Good luck!

John, also consider aperture/lens length to minimize depth of field. It might help minimize some of the refelection problems ...

Cheers!

-Matt

John, also consider aperture/lens length to minimize depth of field.

I was actually considering using a fairly long focal length in order to both increase the distance from the camera (and minimize reflections from the camera itself) and also to reduce any "wide angle" distortion of the perpendicular sides of the picture. I was also going to use a fairly small f-stop to minimize any focus errors.

Whilst a small f stop gives you good depth of field I think most lenses perform best at high f stops.
Just a tip that sure will not help in this case but for small objects that need even lighting I've seen the stills guys use a cocoon. Just a small white tent with holes for the camera. Another gadget good for jewellery is the infinity box.
Bob.