Film vs. Digital
I have no intention of engaging in an abstract debate about the relative merits of film vs digital. I still shoot using both, but I am moving steadily toward the use of digital technology. I used to think that film still reigned when shooting slides, but I no longer believe this is the case, given my experiments in formatting digital images for slide-based stereo projection. Although many film purists will foam at the mouth when I say this, it is entirely possible to use digital cameras to make slides that you could not differentiate from pictures shot directly on film! To see why digital is absolutely competitive with film, let's look at two different stereoviews:
This image was shot on Kodachrome slide film (46 years ago!) that was then scanned, aligned with Stereophotomaker software, and printed at the local 1-hour outlet.
The second view:
was taken with a Van Ekeren digital twin rig, the image files were imported directly into Stereophotomaker, aligned, and then printed at the same 1-hour outlet. As nice as both views may look on the computer screen, they are displayed at significantly lower resolution to ease the download time. Shown below are two full-resolution samples, one directly from the Kodachrome slide and the other from the stereoview image file:
The effective magnification here is about 5X - about what you would get with a Realist-format slide viewer and much more then that produced by a Holmes-Bates stereoscope. Note that, despite the relatively high degree of magnification, there are no visible artifacts when looking at the digital image. This is the result of the following two simple rules when it comes to digital stereo photography:
Use the highest possible digital resolution when taking, scanning, or formatting your pictures.
Never use "lossy" compression. These are JPEG images, but the degree of compression I choose (minimal compression/highest quality) trades modest file size for no effective loss of data. If you don't observe this rule, your pictures will degrade every time they are loaded and saved!
Now, is there a quality difference between the film and digital versions? I honestly feel that anyone without an ax to grind would probably say no. But here's the catch - if I want to use digital techniques to format the card - the only way to go - here's what I have to do with the film to get it into digital form:
Process the film - tough with Kodachrome, easier with E6 films like Velvia, really fast with color negative films.
Clean the film - no matter how good the processor, there will be dust and lint.
Scan the film
Digitally edit to clean the scan - no matter how well you clean the film, it will still be dirty at the level of a high-resolution scan.
In the case of a digital stereo camera, the images are already in digital form and can be imported directly into the stereo software. What's more, none of the tedious cleaning is required! Add to this the fact that I can work with and evaluate my shots if I take a laptop along with me on vacation or whatever, there is no contest when it comes to format. Make no mistake - I like and respect film and I've been shooting film-based stereo for over 50 years, but that doesn't mean that things never change. Form me, I can see no reason to shoot anything but digital, regardless of the final format (stereoview or slide) of the image.
Ralph E. Taggart (Gyrobee@msu.edu)