creation of light table for macro work

[Willie Jan]

Acryl has a name here of "plexiglas". I will have a look where I can get this here local.
Some shops who sell material for modell of ships/airplanes sell this stuff.

[Earl Dunbar]

I made a large table with sweep using 4'x8' acrylic. I used acrylic that had one side frosted, and placed the frosted side down. I used a heat gun to bend the sweep. The front sweep was kept in place by attaching a 1"x2" firring strip (wood) underneath the front edge, secured to the acrylic by bolts and washers. This strip was then secured to the bottom of the main frame structure by using picture hanging wire, i.e. guy wires to keep the sweep taut.

With this setup I was able to photograph fairly large objects. I used coloured paper behind the surface to change the background colour. This way I didn't have to use gels on lighting equipment, and IMO the background colours were better. Lighting the background paper from below allowed me to photograph objects that appeared to float in space. I could also simply place background paper on top of the sweep if that was better for the subject.

[archphoto]

Why don't you guide the light to the plexiglass with a mirror ?
In that way the heat of the lamp will be gone before it reaches the plexiglass.........

Peter

[John Koehrer]

Acrylic diffuser sheets are available for 24 x 48 fluorescent fixtures made of material about 1mm thickness. This is thin enough that you would not have to heat it, just clamp it to your table.

This works OK but the sheets tend to be brittle and aren't very rugged if not treated gently

[Willie Jan]

Why don't you guide the light to the plexiglass with a mirror ?
In that way the heat of the lamp will be gone before it reaches the plexiglass.........

Peter

I have seen a solution of somebody who did send the light first through water, and after that onto the subject also to cool the light.

[Q.G.]

Acryl has a name here of "plexiglas". I will have a look where I can get this here local.
Some shops who sell material for modell of ships/airplanes sell this stuff.

Formido, Praxis, Gamma, and most other such shops will have sheets of plexiglass.

[jerry lebens]

I tend to use 3mm white opal acrylic. You can create a curve using clamps etc, it depends how 'tight' you want your curve to be. Often the sheet can actually be left flat. As long as the sheet remains evenly illuminated and fills the picture frame it doesn't matter whether it's curved or flat : Obtaining a consistently white background depends on the size and shape of the object you're photographing relative to the size of the acrylic sheet and of course the angle of the camera to the background.

As for the acrylic deforming under the heat of lights, it depends whether you're using hot lights or not. With hot lights, you can use mirrors or reflecting panels both to disperse light evenly across the acrylic sheet and avoid overheating. With studio strobes, simply switch off the modeling lights once you've set up, the flash alone shouldn't generate too much heat.

Jerry

[Russ Young]

I have a small sweep table... have used it for nearly three decades. It has a thin white opal plastic that needed no heat to make the bend (remember, you want a wide radius bend, not an angle)... have always used strobes so no idea bout how it reacts to heat.

Just be careful to not scratch it by scooting objects across it. Pick things up. Dust will also produce scratches if you clean it improperly.

Russ