The focusing viewer from 3D World has been several years in the making. It has its shortcomings but it is a capable viewer and is, AFAIK, the only illuminated medium format stereo viewer on the market.

  • Primarily plastic construction
  • Coated achromatic lenses (75mm focal length, 32mm diameter)
  • Focusing by lever operated rack and pinion
  • Adjustable lens separation
  • LED illuminated with a momentary switch and powered by three AA batteries
  • Designed for use with 80x140mm plastic mounts and adaptable for use with 80×132 cardboard mounts
  • 14 ounces ( 397 grams) with batteries
  • Less than $100 (those are US dollars in 2008)

What it does

The most important question is, how do slides look when seen in the new viewer? The simple answer is, they look great.

The slot in this top-loading viewer is an exact fit for the 3D World plastic mounts (80x140mm). It will take 80x132mm cardboard mounts, but they really need an adapter plate to center the images in the lenses. The coated 75mm lenses are a good match for the normal taking lenses on most medium format cameras. They stand well clear of the viewer body and introduce virtually no chromatic or spherical aberrations. The lens spacing is adjustable (between 61 and 66mm) by a simple sliding motion. Focusing is accomplished by moving the lenses fore and aft with a pair of small levers on the left and right sides. Pressing a switch on the right rear corner of the viewer turns on the light.


So what’s not to like on the new viewer? For a new product in the market, it has a curious list of deficiencies and we may as well get them listed up front so we can talk about them.

  • The illuminator is only 12mm behind the slide. This means any dust on the light panel will be in focus behind your slide.
  • The adjustable interocular distance starts too narrow and doesn’t go wide enough. As the 3D World mounts have apertures spaced at 62mm, lenses spaced at less than 62mm is totally pointless and anything less than about 63mm is mostly pointless.
  • There is no provision for external power to the light.

Sure, we’d rather have a perfect viewer, but just how important are these problems?  Blowing the dust off the illuminator isn’t unreasonable and a little bit of adjustment in the lens spacing is better than none at all.  As for external power, I’ll probably end up using some rechargeable NiMH batteries anyway.

So sure, it isn’t perfect, but have you compared it with the other medium format viewers on the market? Have you seen any other medium format viewers on the market? No? I haven’t either. So take this one as it is or take it and add your own improvements. It’s your best and easiest path to show your medium format images in their best light.