Calliostoma zizyphinum

[wolfi]

Hi,
just a guess: for taking a picture, I mount the specimen on top of a wooden rod/bar (2 or three inches long) by using a bit of modelling clay for fixing the shell exactly in the desired position. The wooden bar is sticking vertically in a hole of a wooden platform covered by black paper. The wooden bar is helpful to get the shell sharp in contrast to the background. Then I use a tripod and the self-timer to avoid camera shake.
I hope you see what I mean, it's not easy for me to explain, sorry  .
Kind regards: wolf