Info from Kenrockwell.com
INTRODUCTION
It is a fixed Schneider 47mm f/8 lens attached to a clumsy Mamiya 6 x 9 cm back. It gives about the same angle of view as a 20mm lens on a 35mm camera.
It was built from about 1965 till around 1975.
SPECIFICATIONS
Film: It puts eight 55 x 79mm images on common 120 medium- format film or 16 on 220 film.
Lens: 47mm f/8 Schneider Super Angulon lens, 6 elements in 4 groups.
40.5mm filter thread. Buy a step-up ring to allow use with normal filters.
Five-bladed diaphragm stops from f/8 to f/32 with clicks at each full stop. Of course you may set it to any aperture.
Shutter: 1 - 1/500 second plus bulb. X Flash sync to 1/500 second.
Focus: One guesses the distance and sets it on a scale calibrated from about 2.3 feet to infinity, just like the Hasselblad SWC. There is no rangefinder and there is no ground glass. You focus by guessing, taping or measuring the distance with a separate external rangefinder. These external accessory rangefinders were common photo accessories before the 1960s when very few cameras had built-in rangefinders. There also are odd arbitrary metric conversions exactly at each foot marking, which is weird considering the camera and lens were made in Germany.
PERFORMANCE
This is all of course limited by the lens. It's great: it's very sharp at every aperture, there is no distortion and there are no ghosts.
The biggest gotcha is your ability to guess or tape focus distances and whether or not your camera hasn't been dropped in 40 years and is still aligned properly. To test this make some photos of a far away ridge of trees diagonally across the image at f/8. The entire image ought to be sharp. If one or both sides are less sharp than you've got a problem.
It has a very quiet shutter and very smooth shutter release. This makes it great for long hand-held exposures.
The lens has lots of light fall-off at all apertures. This is normal for a view-camera lens.
I got consistently great results hand held. I returned the camera I had to the used dealer from whom I bought it because the filter thread was so badly dinged I could not attach any filters, which are important to me.