Monday, January 25, 2010

DIY Light Tent

For some time I've been meaning to photograph Jen's engagement ring. Recently, I came across a blog posting on how to create a cheap light tent, and after discovering some discarded tissue paper in the recycling last night, it was a great opportunity to give it a go.

Here's a photo of my setup. I won't duplicate the instructions from the original post, although I will note that I used the box from a case of beer, which is significantly smaller than the recommended 12x12 box.

I photographed 4 things: Jen's ring, a stuffed cat toy (I think it's a pig), a beer (having drank the other 11), and a camera lens. I experimented quite a bit with flash location, direction, and diffusion/zoom setting.

One observation is that it is a major, major pain in the ass to get the right flash power setting, and it's so sensitive to location, direction, zoom and subject. Make one tiny change, and the flash power might need to be halved, or doubled. I used flash settings anywhere from 1/32 to 1/4+0.3. On the plus side, the tent nullifies the effects of the flash diffuser, zoom position, and flash distance, removing 3 variables from the equation. It is sensitive to where on the tent the flash is aimed, depending on the subject.

First up, the ring. For this shot (and all others), I used a 200mm lens at 1/1000s and f/18, ISO 200. I chose the 200mm over a reverse 50mm psuedo-macro because it's just way easier. With the reverse 50mm, I need to hold the camera in one hand, the lens in the other (as separate pieces), and get about 4 cm from my subject. Depth of field sucks, focus is uber sensitive, and working a tripod at those distances is just awkward. 200mm, crop it, save time and frustration.
The shot above is one of the better onces, but the photo below shows that the opening at the front of the box creates some unattractive lowlights at a lower camera position. A fix might be to cover the opening with some white paper, leaving enough room for the camera to peek through to the subject.

Next up, the fuzzy pig. This was the most difficult subject to light evenly. I suspect a larger box may have helped. In the end, the best results were achieved by moving the subject to the rear of the box, and aiming the flash near the front edge.

The beer was a great subject. The embossed logo on the bottle just barely registers when lit from the left (first photo). From the top, we get a much smaller catch light and partially visible embossing (second photo), and a black background (last) makes it more 3 dimensional (while bringing out the imperfections.)

The lens was by far the easiest. I didn't have to frig around at all. Snap, snap, snap, snap, done. I think that's due to the smooth matte black finish and regular shape. The light falls smoothly and happily over it without flaring up.


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