H. G. Dietz
http://aggregate.org/hankd/
Department of Electrical and Computer Engineering
Center for Visualization & Virtual Environments
University of Kentucky, Lexington, KY 40506-0046
Initial release: September 26, 2009
This document should be cited using something like the bibtex entry:
@techreport{bokeh20090926,
author={Henry Gordon Dietz},
title={{Big Old Camera, Tiny New Sensor}},
month={Sept},
year={2009},
institution={University of Kentucky},
howpublished={Aggregate.Org online technical report},
URL={http://aggregate.org/DIT/4X5/}
}
In this digital age, nostalgia about the analog days of yore is becoming an epidemic. People with brand new DSLR (Digital Single Lens Reflex) cameras are diligently seeking out 30+ year old manual-focus prime lenses with their finely-machined full metal jackets to replace their modern multi-coated auto-focus plastic-encased zooms. I've even gotten the bug. In fact, the first two photos in this posting were shot with a 1970s Super Takumar 55mm f/1.8 mounted on a 14MP Sony A350 using an M42 adapter. But this little posting isn't about nostalgia. It's about really great parts being available at very low cost. Big old cameras and lenses easily can be used with modern, usually tiny (compared to the originally intended film), digital image sensors.
The photo at the top of this page is one of the more extreme examples of this principle. It's a relatively indestructable Burke & James Press View camera designed to take 4x5 sheet film... and yes, that's a USB cable hanging off the back. The other end of the cable is connected to this:
This is basically a homemade substitute for the usual 4X5 film holder. Set into an appropriately-sized piece of scant board painted flat black, held in place by hot-melt glue and metal duct tape, you see the guts of a $15 digital camera. More precisely, it is the same model discussed in my Fisheye Digital Imaging For Under $20 posting from back in 2006 (and that's also when I did this little hack). Now, I'm not going to pretend that I get great image quality out of this -- I don't. In fact, things look pretty strange:
However, let's look at that image a little more closely. The Burke & James has a Kodak Ektar 127mm f/4.7 lens and this sensor is quite tiny, so we get quite a huge "crop factor." Basically, we have the equivalent angle of view of a high-power telescope, and the lens is quite fast when you think of it that way. Did I mention that the sensor doesn't have a filter to block near-infrared (NIR) light, so it can work even when there's not enough visible light? I've been using this rig as one of many surveilance cameras, and this one gives a nice close-up of the gate to my property... from 300 feet away looking out a window! The window glass and atmospheric distortion are why the image isn't tack sharp... maybe I should be doing adaptive optics (AO) compensation?
Oh yes; this hacked camera does video too. It may be funny looking for a digital webcam/security camera, but what's wrong with that?
I am not saying that there is no point in buying modern lenses and such. In truth, modern glass often is better (and not radioactive) as well as easier to use. The point is that old photographic equipment definitely has a place in both digital imaging research and creative applications. Don't be afraid to mix and match.
The Burke & James belonged to my dad and I remember borrowing it many times back in the 1970s. Even then, I took advantage of it not only as a 4X5 film camera, but as a testbed for experiments. I had a number of homemade lensboards mounting various odd lenses, and I also made an alternative back that used a broken MC extension tube to mount my Minolta SRT-101 or XK 35mm SLR camera body. The use of 35mm SLRs solved the problem that many random lenses do not contain shutters. Of course, that also isn't an issue if you use either a DSLR body or a digital sensor that has an "electronic shutter" (sometimes called a "rolling shutter") built-in, as do virtually all webcam-like sensors....
One final note: no precious antique cameras were harmed in doing any of this. It is usually quite easy to make all modifications reversible for large-format cameras. One also could modify old 35mm film cameras, although it may be harder to make the changes be non-destructive.
The only thing set in stone is our name.