I usually use 2 or 3 flashlights to lit the whole jewellery in this white environment. And one light or two close the camera where you have some gap as the light should directly effecting the stones without diffusion. Its direction should be where the lens points.
As given examples (attached) show, you should be focusing manually from the very end to the very front of the jewellery using the macro lens as close as you can get to the jewellery. On average I do 10-25 images as I step through the different focal points (because of dept-of-field). Please set the lens’ aperture to F13 or (F11 depending what suits you the best). Please do not shoot F16 or above. Please see attached image for focusing steps example. It is important to have mirror lock up while shooting and doing the focus steps (if you don’t have a leaf-shutter lens). The camera must be very steady so the subject stays at the same place in the frame.
We then use Helicon focus to merge images into an all-the-way-sharp image. This we can do at our end, you shall be please providing white balanced unretouched and uncropped processed TIFF files at the highest output in 8bit per RGB channel.
Would please ask you photographer to do some test shots of the finished elements of the watch. We are aware they might not be assembled yet, but if you the stones are set of and the pave work done on parts we could do a montage and a make it look ready in photoshop.
If you have any questions to ask please don’t hesitate to contact me. I’m happy to speak to your photographer if he needs some more guidance.
I look forward receiving some images in your earliest when you can arrange it.