By
Andy.
I was asked by a shy dgrinner to explain how I get the white backgrounds in some of my shots. The first step, of course, is well, have a white background. in my case, it's some large pieces of foamboard, and also some large white poster board. But this technique will work with any white background, really.
Of course, there are ways to nail it with lighting at the time of shoot - but many folks don't have either the skill or the equipment to do this - so here's a way to get it done, "in post."
Okay - for these balls of clay, i used a snooted external flash unit (full power) off to camera left, and another flash unit onboard the camera (very low power), with a small softbox attached. The snoot and the small softbos are from
Lumiquest. Still, the clay balls are exposed properly, but the background is really grey.
Open the file in photoshop
Choose select>color range
Use the eyedropper and drag it along the full range of the grey background color
Click enter
Now, the background is selected
choose select>feather and try 2 pixels
Do cmd-j (pc: ctrl-j) to put this selection in a new layer.
Now do cmd-l (pc: ctrl-l) and do a levels adjustment
Drag the rightmost slider to the left until you've got white white
