portable light boxes

JC

I'm going to get an hour or two in a museum to photograph a specific obsidian arrowhead. They sent us a picture of it, but with no scale. It has thicker edges than than my test obsidian below.

I need a portable lightbox to take with me, but reading about them, I can't compare the intensity of light output. Anyone have experience with these light boxes?

I'm comparing these:
http://www.adorama.com/VRPLB10122.html
or
http://www.adorama.com/VRPLP811.html

Test shots- first image is my test piece with my laptop screen as a backlight, not quite bright enough to illuminate the internal details. Second image is the piece the museum has, it has thicker edges, so I don't have to worry so much about the backlight overpowering the edges too much.


3rd image- a 125 watt light bulb with parchment paper over it, slightly too powerful for the edges, but I think that's less concern with the museum piece.


In addition to the light box, I'll probably bounce a low power flash off a reflector to the side to fill in some surficial details. If I have time, I'll also try isolating the artifact in front of a black backdrop with a light to the rear and off to the side, but I want to start with the light box. I don't think too much power is a problem, because I can always layer some parchment or rice paper or something on it to attenuate the light more.

Any suggestions for a lightbox? (And I'm hoping my canon 100mm macro (non-L) will perform, but i could rent the L version if it blows mine out of the water)

Don Kondra

I've only shot on a light table but one trick is to cut out a smaller outline of the piece in the paper.

Cheers, Don

ziggy53

A product table and several light tents, so you have some options, are the proper way to approach this sort of project. Did you check with the museum to see what they might have for equipment resources. Sometimes they have very nice stuff, but they may not be trained in the use of the equipment except for simple documentary photography.

3-5 flashes would be typical for lighting.

You may wish to photograph separately for transmissive and reflective properties, compositing the images later in Photoshop to gain the best mix of properties.

Without examining the piece beforehand it's difficult to prescribe a specific strategy.

Also bring some sort of color target, in addition to a physical scale for size, so that you can properly adjust white balance in post.

grandmaR

I've never tried anything like that but I use an old X-ray viewer to look at my slides. The old one came in a big fiberglass box.

JC

ziggy53 wrote: »

A product table and several light tents, so you have some options, are the proper way to approach this sort of project. Did you check with the museum to see what they might have for equipment resources. Sometimes they have very nice stuff, but they may not be trained in the use of the equipment except for simple documentary photography.

They've been a bit vague. Or, my boyfriend has been a bit non-specific with his questions. It's been a trial just finding a museum that can find these artifacts in their archives. The photography setup they showed him at their archive is a drafting-style light table and camera + tripod. No additional light sources. You can see the quality of the image they sent us after they found the piece. If they let us check out the piece, I have access to several macro-setups with side lights, I think the most descriptive term is a copy stand? I'd need to bring a backlight &/or a softbox. Or, I can give up and call in a favor at the Getty, but I want to learn how to do this.

ziggy53 wrote: »

3-5 flashes would be typical for lighting.

You may wish to photograph separately for transmissive and reflective properties, compositing the images later in Photoshop to gain the best mix of properties.

Without examining the piece beforehand it's difficult to prescribe a specific strategy.

Also bring some sort of color target, in addition to a physical scale for size, so that you can properly adjust white balance in post.

Off site I can arrange for three lights plus my on camera flash, on site, it'll be whatever I can bring, judging by what they showed my boyfriend. I was thinking the lightbox for backlight and bounced flash, with a softbox. I'll use a gray card for sure for this. But, this'll be the one time I don't put in a scale in a rock picture, we'll talk about the scale in the caption. That's a good suggestion for doing transmission and reflection images separately, thanks! But, I don't think that just a couple of lights outside of a softbox is going to give me enough backlight. In my tests I needed a pretty strong backlight to bring out the inclusions and texture in the obsidian.