To begin a session, I position the camera above the viewer and roughly adjust
everything. Then I take a test shot and check it with my photo editor to make sure
everything is straight and square. There is some play in the locating tabs of the
viewer, so it's important that every slide be placed firmly up against one corner.
In the screen snip below, you can see that all 4 sides of the image are straight,
and parallel with the cropping grid that I stretched over the image. If the edges
are not parallel, then the camera position will need to be adjusted. Repeat this
process until you're satisfied with the result. Time spent here will save
headaches later on.
When you're satisfied with the setup, write down the cropping coordinates & dimensions. You will need these later for the cropping function.
If your slides are dusty, you could give them a quick brush or blast of compressed air. Also, remember to keep the room as dark as possible to maintain a 'clean' light source. Then it's just a matter of loading and shooting. Use ƒ8 for good depth of field, and 2 sec delay to prevent shake. Note that the slide in the first photo is not perfectly flat on the viewer, but there should be sufficient depth of field to handle this. Also, the room lights are on just for that picture, otherwise I shut everything off except a nearby computer screen.
Here's the result straight out of the camera. Notice how dark the white slide
border is: the darkened room prevents stray light from interfering in any way.
Also notice that the slide is offset to the right a bit, but that doesn't matter
because it will be the same for all photos, and batch cropping will take care of
When I finish the session, I transfer the images to my computer and run them through the batch function of my photo editor for cropping. I use Irfanview, but other editors must have similar functions.
Enter the cropping coordinates & sizes you noted before. This will automatically be applied to each photo, and as you can see below, there are lots of other editing functions that you can do at the same time. The beauty of the batch function is that you can process hundreds of slides at the click of a button. The original image size is 3648 x 2736, but the cropped image still yields a relatively large 2148 x 1430, which is big enough for 300dpi 4x6 prints. After the batch process runs, I can make further adjustments in batch mode, or for individual photos.
Here's the cropped photo. Who knew farm machinery could look so good?
Click here to see the full-size image. Original photo was taken with a Canon EOS 10s and 28-80 USM on Fujichrome Sensia 100.
Keeping in mind that this camera's sensor is only about 6mm wide, this is astonishing detail, so a camera with larger sensor and specialized macro lens would produce even better results. This slide had no obvious problems, but I did see some blown highlights, obscured shadows, and purple fringing on higher contrast slides. Individual slides could be redone either by shooting RAW and post-processing, or maybe shooting multiple images and processing through HDR software. I haven't tried either of those options, so I can't say how well they might work.
In spite of the camera's limitations, the results satisfy my need to be able to easily enjoy (and share) the hundreds of slides that have been sitting neglected in storage because they were too much trouble to view. Even with shipping and duty, my Gepe viewer only cost $50, which I think is a small price to pay for this fun, effective, and easy solution. Thanks for a great idea, Charles!