Medium Format Viewer 
Comparison Notes

Viewer Comparison notes 
by Michael K. Davis

  1. Smaller lenses are less expensive to produce, but support a smaller percentage of the population.  
  2. People with IPD's of 56mm, 72mm, 73mm, 74mm, and 75mm can use the SaturnSlide, but they can't use the Uni-Colour.  
  3. This isn't critical, but which is closest to the focal length of your camera lens?  
  4. The Uni-Colour has about a 4% advantage in magnification when both viewers are focused at Infinity.  
  5. When focused at 10 inches, the SaturnSlide has a 26% advantage over the Infinity-focused Uni-Colour. 
  6. The largest apparent image (greatest immersion) can be had with the adjustable-focus SaturnSlide. 
  7. Uni-Colour's lens separation is a little short of ideal for RMM mounts, terribly short for their own mounts. Lens Separation should equal (or barely exceed) the separation of your mounted Infinity homologs. For the RMM mounts (with an aperture separation of 62mm), Near homologs mounted "to the window" will be 62mm apart and 100% MAOFD Ininfity homologs will end up 2.7mm farther apart still, at about 64.7mm. Thus, the SaturnSlide lens separation of 65.5mm allows you to fuse both Near and Infinity homologs with convergence - you don't have to diverge your eyes unless Infinity homologs extend well beyond 100% MAOFD - to about 125% (in views with excessive deviation).
  8. Uni-Colour's choice of aperture separation is unfathomable given their chosen lens separation. With an aperture separation of 65mm, Uni-Colour's mounts exceed lens separation in their own viewer. Even if you mount your Nears "to the window", using Uni-Colour's mounts in their viewer, you must diverge your eyes to fuse the Near homologs! And diverge them even further to fuse Far homologs! This same design flaw exists in their rotary drum viewer. I brought this to their attention in Jan 2004. If they don't want to redesign their viewers, they should at least redesign their mounts to an aperture separation that's 3.5mm less than the lens separation (changing them from 65mm to 61.5mm). And if that doesn't leave enough of a septum between the 55mm apertures - oops - it's time to make those smaller, too!  
  9. For reasons discussed above, the Uni-Colour viewer works better with the RMM 50x50 mounts  
  10. Uni-Colour's diffuser is much darker than the SaturnSlide STL viewer in equivalent ambient light.  
  11. Uni-Colour got this right! Any accumulated dust on the diffuser is too far away to be in focus.  
  12. Well, if you're shooting MF3D for greater immersion, read notes 4, 5, and 6 again. Also note that some fraction of those people who can see fine in an adjustable viewer, won't be able to use a viewer fixed at Infinity. I, for example, am a little bit near sighted in the right eye. Everything from about 100 feet to Infinity is a little soft in that eye, but just fine in the left eye. I have no problem finding a closer than Infinity focus position in the SaturnSlide that presents very sharp images to both eyes, without glasses. I can't get my glasses up to the lenses with the Uni-Colour viewer's wrap-around design, and without my glasses, the right chip is soft. I have no way to make it sharp. Even if I could get my glasses closer, their reflections would spoil the experience. How many people do you know who can't see sharply in one or both eyes at Infinity? They need adjustable focus.  
  13. Both are light enough to offer no advantage to the Uni-Colour except perhaps for handicapped users. The Uni-Colour is so light, I think a smart marketing move would be to add some weight to the viewer just to make it "feel" more substantial (less toy-like), while at the same time increasing its inertia for the sake of steadiness. The SaturnSlide can get away with being light, because it doesn't look cheap.  
  14. The SaturnSlide Light Box kit is $85.00, partially assembled, but is a big improvement over STL use.  
  15. I'm too fastidious to actually enjoy working with my hands, but it's a great feeling when you're done.  
  16. At first glance: "cheap plastic 1960-ish toy" meets "early 20th-century hardwood craftsmanship".  
  17. The smaller lenses have afforded the Uni-Colour design a very comfortable tunnel for the nose  
  18. Several "lay" people I've shown both viewers to are surprised the Uni-Colour isn't less than $69.00 and that the SaturnSlide isn't more than $225.00. They don't appreciate the quality of the "toy viewer's" lenses, nor the value added by assembling and finishing the SaturnSlide. Still, on appearance alone, I think I'd be hard pressed to sell a Uni-Colour viewer for more than $30.00 at a craft fair, taking a loss on the viewer so that I could sell some views at a profit.  

    Viewer Comparison notes by Michael K. Davis