Most clear containers are plastic one where the bottom is usually heavily scratched. Glass containers usually end up in pieces in my fish room so I don't have any. BTW, most containers, plastic or glass, the bottom is thicker as well. Again, holding a glass container with water over one's head and try to take picture is just too acrobatic for me to perform by myself. Maybe you can set one up with a glass tank on a table with part of the table top cut out so you can take picture lying down under the table looking up to the tank bottom.