A New Mostly Lumen Camera

My much beloved Lumenbox, the creation of Jorge Otero and the namesake of this blog is growing very long in the tooth. It's been severely abused and seen almost daily use in all kinds of weather. These days it's literally held together by duct tape. I think the Lumenbox has done quite well for a very well crafted laminated paper camera.

For a while now, I've been thinking of experimenting with some inexpensive plastic lenses with the end goal of eventually building a large format lumen camera, but a little faster than the f/4 of the Lumenbox. The reason I've been thinking of a larger aperture is to shorten the very long exposure times it takes to achieve the colors that I'm interested in. Typically my exposures are 5-12 hours, or even much longer.

The camera I built yesterday is a baby step towards my eventual goal. It's made from a 3"x3" paste board box and only uses very slightly larger photo paper than the Lumenbox, 7x7cm for my camera vs 6x6 for the Lumenbox. I think with the current lenses I could possibly use a bigger box. I plan on trying 4"x4" or even 5"x5" boxes soon.

Sourcing lenses was a little more difficult than expected, at least as far as finding lenses at a price I was willing to pay. There are tons of cheap plastic meniscus and other lenses on the web, but many don't specify a focal length, which I know I could figure out after I purchased them, but still, I was hoping to find lenses with some specs already in place. I wound up buying some 63mm focal length x 45mm diameter plastic Plano-Convex lenses which looked promising on arrival. When I held them near a wall they projected a decent size, decent looking image. They seemed to have promise!

I mounted one in a box that I had sprayed flat black on the inside, cut some photo paper and made stick on velvet light seals and a very crude matt board shutter for it. I did fit it with interchangeable apertures; I made f/4, f/8 and f/64 apertures for it. The f/64 aperture is so that I can use it as a conventionalish camera, which I hope to try tomorrow.

Spraying the inside flat black was a mistake as it helped to seal the camera. When I dip the photo paper in water, the water vapor has no where to go but disperse in the camera and fog the lens.

I'm about to begin on a new prototype which will be black velvet lined. I'm sure I'll still have to go light on the water (which seems to facilitate the lumen process) but it will hopefully be somewhat less prone to fogging. I'll also fit the new model with a tripod mount, I'm using up lots of gaffer tape mounting the current camera to various surfaces.

I have an f/8 exposure going right now, which will be too late for publication of this post.

I also ran out of what had become my standard paper, Arista Edu Ultra grade 3. I'm using some Foma MG Classic which seems to be working for now.

Below are some shots of the first model Son 63 Dual and the first couple of f/2 exposures. Both are 1/2 hour exposures.