Trouble with reflections

[klpurkett]

My grandmother has a couple antique portraits in oval frames with convex glass. The backs are sealed, and she doesn't want to try to peel the paper backing off, but she would like me to try to take a picture of the portraits, so she can print them off and give family members copies of the portraits. I'm having trouble figuring out how to photograph these, as the convex glass reflects everything! Anybody have any ideas for this? Thanks!
Kristy

[Mike Buckley]

This is a very complex situation requiring no easy solution. Your easiest solution is to light the subject evenly using a light on each side that is at the same distance and angle as the light on the opposite side. Doing so will render a reflection of the two light sources. Even so, capture the image. Re-position the lights maintaining equal distances and angles to create the reflections in different areas. Capture the scene again. You may need to do this a third time or fourth time until all the images, once merged, display no reflection of the light source. Merge the ideal portions of the images.

If that method doesn't suit your needs, buy the latest version of Light: Science and Magic.

[klpurkett]

Thanks for the helpful and detailed response, Mike! Hmm... This sounds like it might be even more complex than I was afraid it might be. But I think I'll give it a shot anyway (sorry, bad pun)... Thanks again!

[rpcrowe]

In one photo lab that I worked, we used polarized light sources for working with glass covered artwork or photos.

http://chsopensource.org/2013/02/27/...documentation/

[William W]

Try shooting the images with the pictures laying flat on the ground under a EVEN cloud covered daylight using a CPL (Circular Polarizing Filter).

You might need to move around a bit and jiggle the CPL. Obviously you cannot stand directly over the pictures so you might need to correct the geometry (shape) in Post Production, Photoshop "lens correct" will do that.

WW

[klpurkett]

In one photo lab that I worked, we used polarized light sources for working with glass covered artwork or photos.

http://chsopensource.org/2013/02/27/...documentation/

Thanks for the link, Richard! Wow... That is quite complex! Interesting, though.

[klpurkett]

Try shooting the images with the pictures laying flat on the ground under a EVEN cloud covered daylight using a CPL (Circular Polarizing Filter).

You might need to move around a bit and jiggle the CPL. Obviously you cannot stand directly over the pictures so you might need to correct the geometry (shape) in Post Production, Photoshop "lens correct" will do that.

WW

Thanks, Bill. A polarizing filter crossed my mind, too. I don't have one yet, but this just might be a perfect excuse to "need" one. I suppose if I'm far enough away from trees/buildings/etc a very overcast day could be just the ticket. Thanks for the idea! Seems like this might be the most straightforward approach as far as post processing is concerned.

Thanks again!

[Val Mansfield]

Not quite what you are looking for, but you may get some ideas from https://www.youtube.com/watch?v=b3q6aIBc_cc

Val

[Mike Buckley]

The issue my explanation helps you with has to do with the fact that the glass is curved. That characteristic will probably make it impossible to capture the subject in one shot without getting reflections of the light source. The polarizing filter won't be much help in your situation because it will affect only part of the glass at a time.

If the glass was flat (not curved), the polarizer might help as others have suggested.

[Mike Buckley]

I suppose if I'm far enough away from trees/buildings/etc a very overcast day could be just the ticket.

Your best bet is to create an isolated environment that allows you to light the subject while preventing anything else being reflected in the glass. Creating a tent of sorts using black material is one way. Nothing other than the light source will be reflected in the glass.

Another ways is if you have a large, dark room. Move everything except the subject to the edges of the room and light only the subject, leaving the rest of the room dark. If the room is dark enough, nothing other than the light source will be reflected in the glass.

[William W]

. . . A polarizing filter crossed my mind, too. I don't have one yet, but this just might be a perfect excuse to "need" one. I suppose if I'm far enough away from trees/buildings/etc a very overcast day could be just the ticket. Thanks for the idea! Seems like this might be the most straightforward approach as far as post processing is concerned.

See last two images in Post #5 of this thread and the explanation therein.

You don't necessarily have to be far away from trees; it doesn't necessarily need to be "very" overcast - "evenness" of the overcast is more important: you need to be prepared to fiddle and get your angles correct and the CPL well tuned.

It is a simple approach.

WW

[Mike Buckley]

Bill,

The subject has curved glass, not flat glass.

[William W]

A large part of how successful a CPL will be, is dependent how much of the image frame is occupied by the convex glass covering of the pictures and what is the radius of that convex glass ofn the pictures.

WW

[William W]

Bill,

The subject has curved glass, not flat glass.

Yes, thanks. I knew that from the get go. I was replying as you were altering me.

. . .

[William W]

. . . we (Mike and I) are writing at the same time.

To be clear I am not debating Mike's ideas.

The glass covering the pictures might be horridly curved i.e. a very small radius, and the pictures might be huge – in which case it will likely be a problem or impossible with a simple approach: on the other hand, the convex curvature of the glass might be slight i.e. large radius and you (Kristy) might be able to get the picture placed in the frame just so the CPL works on all or mostly all of the glass.

My suggestion was pre-empted by “try” – and that word was purposely chosen. If a simple solution works, then great, if not then not much is lost.

For clarity, my suggestion was in addition to others’ suggestions and not a debate against any.

If Kristy can get hold of a CPL it might work. It has worked for me with watch faces and clock faces. Probably not a good idea to spend $100 on a CPL to make a test - but if Kristy an get hold of a CPL and is prepared to take time I think it is worth a shot.

WW

[klpurkett]

See last two images in Post #5 of this thread and the explanation therein.

You don't necessarily have to be far away from trees; it doesn't necessarily need to be "very" overcast - "evenness" of the overcast is more important: you need to be prepared to fiddle and get your angles correct and the CPL well tuned.

It is a simple approach.

WW

Thanks Bill. That was a very eye opening example... Thanks for the link. I will look into either borrowing/renting/purchasing a CPL filter. And thanks for the clarification about the suggested shooting environment.

[Mike Buckley]

if Kristy an get hold of a CPL and is prepared to take time I think it is worth a shot.

Agreed. Whether or not the polarizer proves to be a solution, the experience of using it and seeing the results will be highly informative.

[klpurkett]

Not quite what you are looking for, but you may get some ideas from https://www.youtube.com/watch?v=b3q6aIBc_cc

Val

Thanks Val! This was interesting... Although I do think the curved glass will prove itself troublesome.

[klpurkett]

The issue my explanation helps you with has to do with the fact that the glass is curved. That characteristic will probably make it impossible to capture the subject in one shot without getting reflections of the light source. The polarizing filter won't be much help in your situation because it will affect only part of the glass at a time.

If the glass was flat (not curved), the polarizer might help as others have suggested.

Hmmm, I see your point. I'm pretty sure my Photoshop skills are not strong enough to successfully merge numerous images, but I guess there's nothing like trial and error for learning. The frames are fairly large (about two feet tall by a foot wide, I'd guess).

Thanks for the advice here....

[klpurkett]

Your best bet is to create an isolated environment that allows you to light the subject while preventing anything else being reflected in the glass. Creating a tent of sorts using black material is one way. Nothing other than the light source will be reflected in the glass.

Another ways is if you have a large, dark room. Move everything except the subject to the edges of the room and light only the subject, leaving the rest of the room dark. If the room is dark enough, nothing other than the light source will be reflected in the glass.

I see what you're saying here, though my minimal equipment could prove a limiting factor. I have a camera, two cheep lenses, a grey card, and that's it. I'll try this at night down in their basement, as that's the darkest place I can think of for it.

This little project just might be a bit out of my range of ability right now... We'll see. I'll try a few things and see what happens, but I'm not going to hold my breath that the results will be satisfactory. A learning experience perhaps, but that might be the end of it.

Thanks again.