Shooting Diamonds

Shooting diamond rings in motion isn't easy. You need pin point light sources that are easy to aim into the stone and not spill on the setting. You need to support and move the ring smoothly. You need to keep the stone in the same place as the ring moves so the point lights don't leak on to the rest of the ring. The rest of the ring has to be lit with soft light to look good and show it's design. The camera has to smoothly tilt if a stone to full ring shot is needed. For "kicks" within the diamond to move, either the stone, camera or lights have to move. Light reflections off the faces of the stone are not desired, just from the inner facets. We found that Zirconium's looked better than real diamonds. So... here is one way.

The ring is mounted soldered on to a shaft that fits into a motor that rotates the ring about its stone. That motor is mounted in a motorized crank so that the stone still stays center as the rings rotated about the stone in two axis's. The camera has to smoothly tilt down as you zoom out to reframe the ring as the crank moves. A gear head will work. The camera has to be nodal so the focus holds.

The lens: I replace the front element of an Angenieux 12-120 with a f1.2 - 55-mm Nikkor lens group. This modification will not zoom all the way wide, but it makes the lens into a true macro zoom. I then extend the lens with a 2.2 x Birns and Sawyer extender to cover 35 mm. This makes the lens slow by more than 2 stops. You also need to stop down a lot (f-5.6 or more) to get a decent image and all the depth of field that you can get. Newer fast films would help. To gain more exposure we shot at slower camera speeds. This makes very smooth, precise moves necessary.

Lighting: The ring itself needs a lot of soft light through a ring of Marlux or the like. Pinpoints of light for the stone are from "light cannons". We made ours out of small slide projectors with 1/4" and smaller mattes at the film plane. We then projected that image through 2" IPS pipe with black velvet paper inside to reduce reflections and a 4 to 6 inch lens close to the stone. Enough working distance for the zoom, soft light for the setting and light cannons is important. We used "grip eliminators" to hold the light cannons. Black velvet covered the crank and motor that spun the ring about the stone. The velvet went black on film. Double AA battery Mini Mag lights without the reflector can work for small light sources with lenses to project into the stone. We always used a 1/4 or more blue gel to cool the light in the stones. (See Steady Effects Stand/Grip Eliminator.)

We also rigged the camera and product to the same support, a long Ubangi. Shooting from a dolly to a separate rig would have too much movement. Dolly arms can be propped from the ground for better product shot steadiness.

Making a rig to hold the ring while soldering on the shafts on is important. The client removed the solder. Small torches are needed for soldering.

This could now be rigged to motion control as we used 3 people to do all of the actions. A tape recorder counted numbers for consistency.

If you are dealing with numerous stones not in their settings you can spin them with pulleys behind a plate with a long drive belt to a motor. If you suspend them far enough above the back plate, you can avoid too much light on the black velvet covering the plate.

Paint the shafts shiny black so they reflect the black velvet as black on film.

To light a large stone with no mounting, you can hang it with epoxy on one edge and remove the support in post. We used a relay lens and an internal matte to remove the support.

"Macro Zooms" do not zoom in the macro position.

© Copyright 1999-2004 Ron Dexter. All Rights Reserved.