Instructions
Read about the difference between daguerreotypes, ambrotypes and tintypes at the Antiques Roadshow website (see Resources below). The three types are often confused because they were produced around the same time period and displayed in leather cases. The daguerreotype was the result of a process in which a copper plate was covered in silver, giving the finished photo a mirror-like appearance.
Expect a wide range in prices among daguerreotypes. Current prices range anywhere from $15 to thousands of dollars, depending on the quality, content of the image and condition of the plate (and, seemingly, the whim of the seller).
Consider additional factors including size, additional coloring (often hand-applied tinting), a well-known maker, and whether the subject is someone important in history.
Research current prices on the web at Fine Dags or American Daguero (see Resources below).
Check out the Kovels website. The husband and wife team are well-known appraisers (see Resources below).
Observe online auctions for daguerreotypes at eBay.
Contact an independent appraiser if you feel your daguerreotype may be valuable. Do your homework first, however. With the wide range in prices on the market for daguerreotypes, you wouldn't want to pay for an appraisal that is unwarranted.