Original photographs by Ansel Adams are defined as photographs printed by Ansel Adams from the negatives he made (photographed and developed). Most will range between $4,000 and $70,000.
Keratosis is the term for any condition that is a benign overgrowth  and thickening of the epidermis.
The fourth layer in the epidermis is called the stratum lucidum, or the clear layer. This layer is present only in the fingertips, palms, and soles of the feet. It is 3-5 layers of extremely flattened cells. The fifth layer, or horny layer, is called the stratum corneum. This is the top, outermost layer of the epidermis and is 25-30 layers of flattened, dead keratinocytes. This layer is the real protective layer of the skin.