technicals - 10d and LED high speed trigger

Canon RF 24-70mm f/2.8 L IS

12/15/2006 05:52:14 PM · #1

i have a chance to possibly play around with some hi-powered LED lights. these are adjustable down to a 1us light burst ( .000001 sec ). i would like to configure the camera shutter to activate the light in hopes of using them for some high speed photography.

these aren't typical LEDS you find around normal daily life - these are hi-power & and used in manufacturing for capturing images of say doritos as they pass down the flavor powder conveyor. ie: they are powerful enough to allow reasonable aperture and shutter speeds.

i don't have them in my possesion yet, but...

they require 5v of DC power and i need a means to have the shutter and lights in sync - where i can then adjust the delay/time of burst of the LED's to coincide with the moving subject. will my 10d output 5v to the LEDs -w/o major camera surgery? because they are LEDs - they won't spread light all over, but be more of a straight line directional lighting. so i think i could use a longer light burst in order to have the subject lit when the shutter fires -w/o worrying about light spilling off the subject area and into the camera. however i can't just leave the LED on and fire the shutter - the delay settings are quite short so i would need to have the shutter bascically activate the lights.

any thoughts - i would provide more info - but i am waiting on that myself ;}

Message edited by author 2006-12-15 17:55:20.

kirbic

Canon EOS R5

12/15/2006 05:56:18 PM · #2

You're going to have to have some sort of controller for the lights. Then you'll need to figure out what sort of inputs that controller has, and whether the camera can provide a signal that the controller can understand.
The 5V power for the lights is going to be *high* current. That's a must in order for the lights to output any useful amount of energy (light). They are more efficient than a xenon tube flash, but you're still looking at a lot of energy.

12/15/2006 06:01:47 PM · #3

this is the info i have. so maybe i have it mixed up.

Originally posted by me:

I have some semi-scrap (old) strobe controllers that arenâ��t quite as fast as the top of the line strobes, but do a good job. I can get one to borrow no problem, and a simple LED light to show you what Iâ��m talking about. The strobes are triggerable; I.E. you send a small 5volt signal and it will turn the light on, with a pulsewidth as short as 1uS (that is, the light turns on for .000001 seconds). You can time this trigger with a shutter of a camera, so it kinda acts like a high speed camera flash that you can position anywhere you want (might require some tinkering with the camera electronics; I donâ��t really know how to work cameras with external triggers?).

Gordon

RIM BlackBerry Curve

Canon EF 85mm f/1.8 USM

12/15/2006 06:09:16 PM · #4

Something to consider. You don't need to sync the shutter and the lights, not really.

You just need the shutter open during the period the light fires. The shutter could be open for a second or more, if you were in a dark room, and the light pulse just has to happen during that period.

When I've played with high speed strobe, I'd usually have a several second shutter speed. I designed and built an infrared trigger attached to a normal flash unit. The same thing could be done here to generate the required 5V pulse. I built one with a variable timer to allow a delay to be introduced.

As in most flash photography, all that controls the resulting image is the flash duration/power and the camera aperture. The shutter speed doesn't have much to do with it (other than controlling the ambient light exposure) Shoot in a dark room (or effectively dark given the shutter and aperture being used) and the only exposure is flash power and aperture. Just leave the shutter open.

Message edited by author 2006-12-15 18:10:52.

fotomann_forever

12/15/2006 06:19:14 PM · #5

Originally posted by Gordon:

Quite true and the 10D can't sync the shutter to flash at speeds higher than 1/200 sec anyway.

____

As far as controlling the LED's from camera, I'd put a wien Safe-sync between the camera and the light controller, whether it be an oscialtion circuit or a simple relay.

Opto-isolation is your best bet for the firing mechanism as it keeps the current out of your camera.

Message edited by author 2006-12-15 18:20:30.

might give you some more ideas

12/15/2006 08:19:04 PM · #6

yeah i understand that. but i am not sure how to tie me pushing the shutter button to the lights actually being engaged. engaged in the sense that it might be a delayed fire of the lights. even with the shutter being sort of a non-issue - i'd like to be able to semi-control the timing.

for instance - having the subject come - into - through - and out of the line of light - is going to have a different effect than the light firing directly across the subject for a split second.

Originally posted by Gordon:

Message edited by author 2006-12-15 20:23:10.

Gordon

RIM BlackBerry Curve

Canon EF 85mm f/1.8 USM

12/15/2006 10:52:54 PM · #7