8"x10" Nested Box Camera
This new camera is nearing completion, enough so I was able to achieve "first light" this afternoon.
It's a nested box camera, employing a single-element meniscus lens (diameter ~4") that was salvaged from a photo-lithographic stepper (used in the semiconductor industry to print integrated circuit patterns onto silicon wafers). When finished, the front portion will be fixed to the bottom plate, with the rear sliding in and out for focusing. It employs standard Riteway-style 8"x10" sheet film holders.
The camera is constructed from black foamcore, the front half is laminated on the outside with a thin, wooden adhesive laminate used for countertops. The rear of the sliding portion, made from scrap wood, employs a set of aluminum "L" channel to clamp the film holder, via thumbscrews, permitting an uninterrupted view of the rear, where I will insert a removable ground glass viewscreen, same thickness as the film holder.
There is a removable aperture stop, behind the shutter; I only made two so far, the one used today is 3mm, giving a focal ratio of F/90, a hyperfocal setup needing little in the way of critical focusing. The other aperture stop is ~3" diameter, giving a focal ratio around F/4 wide open. I plan on making a set of various sizes.
The shutter is a simple guillotine shutter made from masonite, covered on the reverse side with adhesive craft felt, as is most of the inside surfaces of the box that aren't black foamcore, to absorb light reflections.
The camera will have two operating modes: 1) Hyperfocal mode, F/90, no critical focus needed; 2) Wide aperture, narrow DOF, taking advantage of the single meniscus lens's abberations to produce soft-focus images, for instance for portraits.
Since there is no mechanical shutter, I have to keep the shutter speeds >1 second, so the hand-operated shutter can be used accurately.
Today's first images were made using preflashed grade 2 paper negatives.
Beautiful camera. Well done.
Several images from today's shooting with the near-finished camera. I'm still working on finishing the removable viewscreen. So for this afternoon's landscape images, captured along the foothills of the Sandia Mountains, I used a smaller removable viewscreen that I had made for a 4"x5" camera. The lens was stopped down to 3mm, about F/90, exposure ~3 seconds onto preflashed grade 2 paper negatives.
Later in the evening, after processing the above images, I setup a still life composition in my shop, this time with the lens opened up to F/23 (accounting for bellows extension, nominally F/16 at infinity), 1 minute exposure, lit by a single low-wattage work lamp.
you've inspired me to make one - great work
Last night I made some contact prints of negatives exposed yesterday. I came to the conclusion that the big meniscus lens just isn't as sharp as I'd like; in fact, comparing these contact prints with ones from a cardboard 8x10 pinhole camera (with optimized pinhole), the meniscus lens images are softer.
So I considered other alternative lenses I have at my disposal. One obvious candidate is my 150mm binocular objective, which I've used repeatedly in my Speed Graphic. It has incredible off-axis softness and blurr, depending on aperture, but knew it would be too short for infinity focus in the big 8x10 box camera. Still, for close-ups where bellows extension is the norm, I figured I'd give it a go.
I fashioned a bracket from scrap wood and foamcore that mounts the binocular lens in place of the meniscus. Surprisingly, it covers the 8"x10" format. So I concocted this still-life on my workbench, the main subject being my WWII-era Anniversary Speed Graphic. Preflashed grade 2 paper negative, 7mm aperture (f/38 effectively), 50 second exposure. You can see the reflections of my work light in the lens.
I'm pleased! :)
That is really awesome and inspiring!
The formica is a wonderful touch! It is really wonderful.
I/m very impressed with the quality of the meniscus lens---especially the still life of the bananas. Is there a place to find these lenses for sale? I would like one to use on my R.O.C 8X10 with about an 18" focus.