Computing stuff tied to the physical world

Low-end light box

In Hardware on Oct 5, 2010 at 00:01

Yesterday’s post was about trying to make better pictures for this weblog. The jury is still out on whether the results are dramatically better, but here’s the setup I used – first an add-on for the Nikon D40 built-in flash:

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What it does is place a small piece of mirror (extracted from a flatbed scanner) in front of the pop-up flash to reflect all the light up. It’s made of a few little scrap pieces of foam board, glued together to keep the light from directly reaching the object, reflecting the light upwards instead. It’s held in place by friction:

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That solves one half of the problem. The other issue is to get light all around the object to avoid excessively sharp shadows. I made a little “light box” for that, from a little wooden storage box with the interior covered entirely in white foam board:

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I can now place the object on the bottom in the back, and sort of peek inside with the camera. The trick is to make sure that the flash sends its light inside the box, bouncing up against the top foam board.

That’s basically it!

The reason I chose this setup, is that I need the height to get the flash inside, and I wanted something that could be easily dismounted and stored away. Like this:

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All the foam pieces were cut from five A4-sized panels, because I’ve got lots of ’em lying around. Everything is held together purely by friction, so it’s trivial to assemble and disassemble, but also very easy to replace one of the form boards if it ever got dirty or damaged.

I can also rearrange things, and put the wooden box flat on the table, with the camera looking down into it for shots straight from above.

One detail I’d still like to improve is the amount of diffuse light striking the object at the front. There is currently still a bit of a shadow. One idea is to cover the top with aluminum foil, and perhaps also a surface inside which is slanted forward. Here is a cross section:

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Here is the current setup (no foil yet), with the slanted top panel showing on the left:

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Note that foam board is very easy to use for “broken” panels – simply don’t cut them all the way through:

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Simple. Now I just need to understand all the adjustments and photo stuff a bit more…

Update – here’s the last trial – different angle, slightly more interesting surfaces, but the FTDI pins are too washed out:

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