AboutDavid Silver Expertise I'm an expert on all types of antique, classic, and contemporary cameras, as well as the general history of photography. Everything from ancient box cameras to modern single-lens-reflex; from simple Kodaks to sophisticated Leica and Nikon; from glass plates and roll film to movie and 35mm. I can identify and appraise them, explain how they work, and offer insights on their restoration and care. I can also provide historical background on vintage cameras and equipment, and guidelines on their purchase and sale.
Experience I've been a professional photographer and a student of the history of photography for nearly 30 years. During that time my collection of vintage cameras and photographic paraphernalia has grown beyond 2000 significant pieces. I've published nearly 70 articles in the field, including 16 in the popular "Buying Classic Cameras" series for PHOTO SHOPPER MAGAZINE from 1995 to 1997, I'm currently a contributing editor for CAMERA SHOPPER MAGAZINE and McKEOWN'S PRICE GUIDE TO ANTIQUE AND CLASSIC CAMERAS, and I've written numerous entries for WORLD BOOK ENCYCLOPEDIA. Portions of my collection have been displayed in museums and special exhibits in the past two decades, and many of the items were photographed as illustrations for books. In 1985 I founded the International Photographic Historical Organization (InPHO), which eventually evolved into its intended purpose as the best first resource for information on the history of photography. I'm also a founding member of several e-mail forums dedicated to specialized areas of photography, and I'm the moderator of the Internet Directory of Camera Collectors (IDCC), which remains the largest and most successful such group in the world. For more information about the International Photographic Historical Organization and its many services, please visit its web pages at:
Question Hi David,
Old folding cameras sometimes use meniscus lenses. What are the properties of a meniscus lens? I'm interested because I've used convex and concave lenses for experimental photography but have no experience with meniscus lenses. Any information appreciated. Thanks.
Regards,
Usuff
Answer Hello,
If you've used simple convex and concave lenses for photographic experiments, then you've probably already had experience with "meniscus" lenses.
In optical physics, a true mensicus lens is one that's convex on one face and concave on the other, and the radius of each face is exactly opposite, such that the curvatures are neutralized. In other words, a true meniscus lens will NOT project a photographic image! However, in the photographic industry, the term "meniscus" was used generically to identify ANY single piece lens. So there are "meniscus" lenses in many old folding bellows cameras and box cameras that are actually bi-convex (convex on both faces, although not necessarily the same radius), plano-convex (convex on one face, flat on the other), or convex-concave (convex on one face, slightly less concave on the other, so the radii do not neutralize each other). The vast majority were bi-convex. Why did the manufacturers do this? For the simple reason that "meniscus" sounds a LOT more fancy than "cheap piece of magnifying glass"! If you've experimented with convex lenses, then you've been using more or less what the manufacturers were calling "meniscus" lenses a century ago, and you already know all their properties from your own experience. They ARE capable of sharp pictures, but they are slow (usually no faster than f/8, and much better in the f/16 range) and they can exhibit too much chromatic aberation (they bend different colors of light at different angles, so on panchromatic black & white film they tend to blur a bit). The next step for you? Try combining convex and concave lenses together in an attempt to create a doublet or achromat lens. If you succeed, you will have a lens that greatly decreases chromatic aberation, and will render superb results at f/8. The old camera manufacturers called this combination an "achromatic meniscus" lens, which made no sense in optical physics, but it sounded so good in advertising!
