Daguerrowhatsit

Everytime I go junkin', I see antique photographs mislabeled as to their process. Sellers do this either because they just don't know the difference or because they want to charge you more. So, before you go out to the flea market this weekend or buy online, here's a little education so you know what you're getting.

Daguerrotypes, so named for their inventor, are one of the oldest photographic processes. They were very involved to make and used chemicals like fumed mercury. So, these are generally the most expensive. For this reason, this is the most common mislabling. However, these are also the easiest to spot if you know what to look for. An image is formed onto a substrate of highly polished silver. For this reason, when held at certain angles, you can't even see the image – just a mirror. But if you reflect something dark into the image, it appears (one of the reasons it comes in a case with dark velvet lining). The detail, sharpness and tonal qualities on a Daguerreotype are really beautiful which is another reason they're sought after and pricey.

Ambrotypes and their cousins Tintypes can get trickier to tell apart. An Ambrotype is an image on glass. Since it's the grayish and white highlights of the image that form on the emulsion, the glass is coated on one side (sometimes the emulsion side, sometimes the reverse) with black lacquer to form the final image. This will not reflect at all like a mirror, and you might be able to see on close inspection the white emulsion on the glass. Ambrotypes can also be printed on colored glass or ivory, but these are rarer.

Tintypes were cheap and easy to produce (relatively speaking), so many people could own them, and tons exist today. A tintype makes an image much like an Ambrotype, but on a thin metal substrate that has been laquered black. They tend to bend easily and many have the emulsion badly cracked. Sometimes I see these in nice cases with a piece of glass over the top, and it will look similar to an Ambrotype unless you inspect it closely. The quality of a tintype is the poorest of the three processes, and they have an overall grayish look.

Any of these processes might have some hand coloring on the final image. Sometimes just some "pinking" on the cheeks, sometimes white to accentuate highlights, and often jewelry is gilt.