I photograph all my stones in my office where I have three 4000K CFL spot lamps (sunlight is around 4800K, but I’ve found those lamps to have too much blue) in an adjustable ceiling mount, so thy point down (from over my shoulder) to a photographing desk, to avoid most reflections. But this really isn’t much light so I use a tripod for my photography as most of the photographs are done using exposure times of around 1/25 of a second to 1/40th of a second with f-stops of F-7.6 to F-8, so the depth of field is sufficient to keep the entire stone in focus. These slow exposure time would create unacceptable motion or blur in my photographs if the camera was hand held, so a tripod is mandatory. And all photography is done using manual metering mode. Auto light metering will overexpose the stones…especially light colored opal, since I am photographing on a dark background.
At least for now I have a Nikon B700 camera, but I go through a camera every couple years since I am doing so many photographs. The B700 isn’t an expensive camera and seems to do well for opal photography. But it seems like the auto focus doesn’t hold up well. And it’s easy to bump a camera on a tripod and break the camera…oops. The Nikon Coolpix B700 is heavy on the reds (tans and grays have a red tint) and unfortunately blues don’t show up well either. So I use “Auto Color” adjustment in my old Photoshop Elements 2014. This nicely corrects the camera color problems without affecting the saturation or hue. In Elements 2014, I also use “Auto Contrast” and “Auto Sharpen” and then finally adjust the “Brightness” manually so the images don’t come out too bright or to dark. It usually works well and have had very few complaints that the photograph looks too good…something I desperately try to avoid. I would rather have people pleasantly surprised when they open the package I’ve shipped them than be disappointed. In many instances I hold the stone under a 4000K lamp on my computer desk to be sure the image on my monitor matches the stone when doing adjustments in Photoshop Elements.