I've extended my collection with an interesting set of 50 glass 45x107 stereoviews and a simple stereoscope. The stereoviews are published by the Service des Ventes de l'U.N.C. (SDV).
The Glyphoscope was a stereo camera using glass plates, developed by the famous manufacturer Jules Richard from Paris. It was a compact, simple and affordable camera that could also serve as a stereoscope.
When searching for stereoviews to extend my collection, I always pay special attention to images of sites I’ve visited while working on my photo projects. I was delighted to found a slide of Fort de Troyon. It brings back good memories of my visit to this fort in 2015.
Last month I've acquired my second cabinet stereoscope. It's a beautiful late 19th century deluxe rotary viewer, built by the French manufacturer Mattey. This multiple-view device supports paper and glass stereo views in the both 45x107 and 6x30 formats.
The majority of French stereoviews from the First World War are not rare. They were produced in large numbers and are offered on many online auction sites. Much less is known about the photographers, manufacturers and sellers. That's why simple documents can sometimes reveal valuable information.