DIY Ring Flash
A ring flash is such a popular and easy DIY project that I finally couldn't resist the temptation to make one myself. I'll post some detailed instructions on how to make one (like this) when I have more time, but most of you should be able to figure out the essentials just by looking at the finished product.
- plastic dome (originally intended for covering food in a microwave oven)
- a tin (sans fruit salad)
- something with male filter threads on it; I used a very cheap Cokin P filter holder clone
- aluminium baking foil
Total cost of materials (excluding paint and glue) was approx. €7 (and we ate the fruit salad from the tin; it's included as a bonus). Of course, a regular flashgun is also required, and with this method of mounting the flash you need some way to trigger it off-camera (optical triggering by the built-in flash would work nicely since light from the trigger flash is blocked by the dome).
One thing to consider with this method of construction is that the lens cannot have rotating filter threads (when zooming or focusing), because they almost certainly would not welcome having to fight the weight of the ring flash, and the flashgun position would change during focusing (mine doesn't fall even if it's under the ring, but I wouldn't count on it). The best lens for this is a prime with internal focusing (i.e. length doesn't change depending on focus), but an extending macro lens worked fine in my experiments. For flimsier lenses it is probably better to mount the ring on the camera somehow (e.g. with some kind of holder attached to the tripod threads), or hand-hold the flashgun above the ring instead of supporting its weight on it.