High Power Flash.

Intro: High Power Flash.

An ongoing project for creating a high power and speed studio flash (cheaply) that can sync with a chdk enabled camera.

Once I get the new parts (couple weeks ish) I'll make an instructable.
If you don't know what chdk is have a look:
https://www.instructables.com/id/Pocket-Sized-CHDK-USB-Camera-Shutter-Remote/


Currently I can take photos at about 1/1000s consistently.
I believe the limitation is the camera.
As the flash timing moves about +-1/4ms

The bulb is being run at about 7.5j, but is capable of about 32j, so I'm going to get a proper sized tank capacitor and use a voltage doubler off the line to charge it faster.

Comments

[gaveno]

Has any progress been made with this? I am very interested in making one of these.

[Photomancer]

Your limitation is probably in the shutter. The shutter in most DSLR-type cameras have two shutter curtains: the first opens and starts its movement to expose the film/sensor, the second shutter/curtain then follows, the smaller the gap the less "exposure time (but more light needed). The amount of light determines how close the shutters can run together. Cameras have to coordinate the shutters and flash (plus exposure metering, most people don’t realize that flash actually goes off several times until he light level is reached for correct exposure - I mean really fast between flash adjustments)

The problem is the "flash" can be on for much shorter periods, say 1/50,000th of second. I'd suggest, get everything set-up, turn the lights off or very dim (I mean barely able to see) the set the camera on B (Bulb) - shutter stays open. Have you device trip the flash to coincide with the event, say balloon popping. Then close the shutter, and now the exposure is limited to the actual flash duration.

The more clever part will be to have the device with start button that turns off lights about 1 second before "pop" the balloon, the trip shutter, say set for 1 second exposure, then immediately do the "pop", shutter closes after 1 second, then lights come back on a second later. It'll take some tests to get the exposure right for a given distance. But once dialed in, should be good for any item.

Good cameras can go between 1/250th (my Nikon) to 1/500 (Mamiya, different type of shutter) of second with their flash. You've already topped that, but almost all high speed photos are done in the dark with the flash controlling exposure time.

Just some thoughts: Maybe the pin that trips the flash when it touches something and grounds so the circuit is almost instantaneous. A sonic pick-up that is 12'' away will have about 1/1000th of second delay just do to the speed of sound getting there. A laser maybe?

I know much more about cameras a flash photography than electronics, just starting out Ardunio projects. Good work you've given me some ideas. Looking forward to your expanded instructable.

[VadimS]

I don't have a dslr camera, only a cheap point and shoot.

[Photomancer]

Even so, the shutterwill be the limiting factor. Try this: go into a dark room and press the shutter release button. You should a "click"shutter opening, then after a while or when you turn on the light, a second "click" shutter closing. If this happens, have everything set-up, go totally dark, press the release, then trip the flash so it is in time with the event. The shutter should be open and hopefully get enough light to close it.

[etw]

Interesting but I do not see much of an instructable yet

[CieNTi]

I agree