sh0dan // VoxPod

Sunday, March 26, 2006

Hacking a Cheap Ring Flash

(From my photo blog)

Today, my girlfriend and myself continued to play with her new macro lense. I got my Centon MR40 Ring flash out, I bought half a year ago for about $35. It's an old type TTL-lense, which doesn't really work to well on my 20D. It fires alright, but it fires at the lowest level, so it didn't really help.

My first solution was to set an exposure time at about half a second, and have an assistant (me or my girlfriend depending on who held the camera) fire the flash, using the "Test" button on the flash, when the other pressed the shutter release. It worked surprisingly well, except for a few ghosts from the long exposure time.

My second thought was if it would be possible to disable the TTL, and just have the flash fire everything it got. There are no controls on the flash whatsoever, so my only change was to remove the TTL comunication. I did this by covering all but the main flash trigger with tape. And it WORKED!

Wow - a ring flash for a tenth of the price of a Canon. Of course the camera has to be run completely in manual mode. But since macro are such a controlled environment, that isn't much of an issue anyway.