
Got some antique beer bottles to sell on eBay? Photograph 'em better in a light tent.
WHAT YOU NEED
> Decent camera, preferably with a macro lens
> 3/4-inch PVC pipe (26 cents per foot) and T-joints ($2 for 10)
> Ripstop nylon or similar fabric (such as a shower curtain)
> Velcro tape (or other fastening system)
> Big, sturdy table to work on
So you got yourself a digital SLR camera and now you think you're big stuff? Yeah, whatever. The cool kids are into macrophotography - super-close-ups of coins, bugs, flowers, whatever. The best way to capture such small fragments of the world is to isolate your subject in a light tent: a mini tabletop photo studio with light-diffusing walls. Place a few remote flash units (or table lamps) outside the tent, and marvel at your in-tent subject's perfectly even light.
Step 1: PVC for You and Me
Rather than messing with a hammer and nails, it's easier to frame your box with good old PVC pipe. Home Depot has every flavor of PVC known to man. We used 3/4-inch-diameter tubing for our smallish box. Get the stronger, one-inch-diameter PVC if you want to make your box big enough to stand in. PVC is super-easy to cut with a wood saw, or you can buy it precut; either way, you need eight two-foot lengths of pipe, eight T-joints, and four two-inch shims to connect the T-joints.

Sixteen feet of PVC pipe and eight T-joints, all chopped up juuuuuust right.
Step 2: Four Corners Make It a Box
Assemble your box according to the photo below. The PVC fits together tightly enough to frame the box, but you can still fold in the side walls and stash your box behind a door. Note the dual T-joint configuration on each corner post: We used the upper set to hang the sides and the lower set for the top, but you're free to experiment. However you build it, make sure to jam the pipe firmly into the T-joints - we tapped ours in with a hammer.

When you're done, you can flatten your tent and stash it under the bed.
Step 3: Just Add Walls
Since you're building this box to diffuse light, use material that's heavy enough to evenly disperse your flash or whatever light source you use. Ripstop nylon is ideal; heavy cotton sheets work in a pinch; thin, sheer fabrics like silk and linen won't completely neuter the flash and will likely create a hotspot. Attach the two side panels with tape if you're in a hurry, or use Velcro tape if you think you'll ever want to change your material to a different color or weight for special lighting effects.

If you want to skip the tape, just drape a big sheet of nylon over the top and call it a day.
Step 4: Top 'Er Off
Instead of taping the top and back pieces, cut the nylon long enough to span the back and top - for our box, we used four feet and left extra nylon to drape over the front and sides. Now stretch the fabric across the box's top (tightly, but not too tightly), cut one-inch holes above each corner, and fit the holes over the protruding bits of PVC.
Unless you plan on using your light tent outside, you don't need to tape the top.
Links:
[1] http://www.maclife.com/article/hack_your_toys
[2] http://www.maclife.com/article/turn_your_webcam_into_an_ir_spycam
[3] http://www.livingroom.org.au/photolog/tips/macro_digital_photography.php
[4] http://www.maclife.com/macro photography tips
[5] http://www.shutterfreaks.com/Tips/tomhicksmacros.html