Lightbox with even light???

[JoelBelmont]

I am photographing (digitally) my 4x5 negs to make contact prints, and am having a hard time finding a small lightbox (10x12" to 12x18" give or take) with EVEN light. I bought a logan slimedge? and found it uneven at both ends. Looking on B&H both "Just" and "Hakuba" are supposed to be evenly lit (as close to $200 I would hope so)... just wanted to know if anyone had a recommendation...?

Thanks.

[Eric Woodbury]

This is why they make scanners. They are corrected for this. If it is just the ends, then buy a bigger lightbox so the ends are outside your pic. Making a lightsource perfect is very difficult. You can add more diffusion, but more diffusion is inevitably less light.

[JoelBelmont]

I am photographing, at times, 200-300 pages (4 to a page) of 4x5" negs (a backlog of work), so scanning is not a timely option. They are B&W, so color is not important... just even light to render the negs correctly. I am with you on the larger surface... I am currently looking at the hakuba Lightviewer 7000 PRO (8.5x11") which should give me at least a little more edgeroom than the 8x10 that I have now. Still would like any recommendations on affordable lightboxes with even light.

[Eric Woodbury]

You might make your own. Get a larger piece of white plexi and put a bunch of lights behind it. In front of that, a clear piece of glass on which to put your negs. (If you are having problems with newton rings, use non-glare glass.) Using a medium to long lens, focus on the glass and shoot at a bigger f/number. The plexi will act like an oversized light box and the glass will give you a flat surface. Being away from the plexi will place the plexi out of focus. It may seem weird, but even plexi is not 100% diffused and that means you can have some imaging through it. Placing the focus in front of the plexi helps to blur it more. Also, as you won't be using fluorescent tubes in close proximity to the plexi, they will be even more blurred. And finally, mask the excess light around the negs.

Another option, find an old light box from a commercial camera used for making plate negatives. It would be something that an old newspaper would have.

[Nathan Potter]

My old solution to this was to use a home built setup. The copy camera was enclosed on top of the lightbox to eliminate extraneous light from the outside. The films were arranged on clear glass (12X 12 inch format IIRC) and below that was a piece of white cardboard at about 45 degrees from the glass and film copy plane. Then I simply used an electronic flash at about 12 feet distant to expose the film (In your case to capture a digital image). You'll need to sync the flash to the camera thru a long flash cord but should not be a problem.

The idea was that at a great distance between the flash and the white card the variation in intensity is negligible. I used an auxiliary tungsten light directed on the white card for focus then switched that off during electronic flashing. But your digi will need an external sync outlet unless you rig a slave unit that will be actuated from the digi. Anyhow you get the idea and it can be a fast copy technique.

Nate Potter, Austin TX.

[DarkroomDan]

I use an x-ray viewer that I got for free when a hospital was remodeling. I don't know where one would look for these but, since they are quite expensive new, I would think someone must salvage them. They come in a lot of sizes. The viewing area on mine measures 17 x 28 inches and is very high quality opal glass. It was originally mounted in a wall but I built a stand for it so the glass is now a table top in my studio. I have a small (10x12) PortaTrace unit next to my enlarger in my darkroom.

Dan

[Thebes]

I used to have an old 4x5 contact printer that gave an incredibly even light. About the size of a large toaster, and if you can still find one it would probably cost mostly for shipping. I don't recall who made it.

[Archphoto]

Just made some good lightboxes but they were never cheap.

[Gordon Moat]

Try Porta-Trace, also sold under Gagne brand. The two bulb versions are quite good. Construction is strong, but not elegant. You might opt for the wood version over stainless if you want something that looks less industrial.

Ciao!

Gordon Moat Photography

[Drew Wiley]

Everybody and their cat makes a lightbox. Very few actually have even illumination.
The apparent trick is to put a thicker piece of white plastic or more heavily frosted
piece of opal glass on the device to increase the Lambertian scatter, but this also
drastically cuts back the amount of light being transmitted. It also changes the color
temperature. There's also the issue of the ballast. What might seem like a constant light to you might not to film, if you are using the light box for actual photography. Then the quality of the base diffuser becomes an issue, and how this affects both light distribution and color temp. And bulbs vary considerably in quality. In other words, there are light boxes and there are light boxes. Which explains the dramatic differences in price. Maybe you just need something simple, maybe you need the real
deal. Just be aware that the specs can be very misleading, and that they are generally
telling you, at best, the color temp and CRI of the bulb itself, not of the cumulative system.