OMG you're gonna shoot coins with a 24MP full-frame camera? Yer huntin' squirrel with a howitzer.
All seriousness aside, acquire two small gooseneck lamps with small (or no) shades, allowing you to get the bulbs very close to and somewhat above the plane of the lens' outside glass. Use small bulbs - R20 or the like, no more than 50w each will be more than sufficient - to be able to get the light source as close to vertical as you can above the coin. You won't always do it that way, but it's really nice to have close-to-straight-on lighting for lustrous coins.
Get a hood for the lens. You don't want any light bouncing off of anything; that will hurt contrast.
Set lens-coin distance around 12-15". No need to get closer with that lens; with 24MP in-hand you could probably do 24" and still exceed anything I've ever accomplished. Shoot in a darkened room, and if there's a computer in the area turn the monitor away from your work. That'll make setting white balance easier in the camera, and if you can get white balance adjusted in-camera you're gonna like yourself better, later.
With the coin oriented so the camera sees it as straight up, set lighting around 10:00 and 2:00. Use an initial setting of 1/150(ish), ISO 800 and f/8, and vary exposure only to get the lighting correct. You might like only one light (dropping the initial exposure to 1/80 to start) for some coins.
You are, of course, using a good stiff mount, remote (or delayed) shutter, and getting the coin and lens plane exactly parallel, right?
I cannot wait to see what this combination will do. There is no reason why your equipment cannot shoot coins as well as the very best professionals you know. It only remains to dial it in.
Posted 01/09/2010 9:05 pm
