View Full Version : strobe activity during capture

April 10, 2007, 22:46:49
As I understand it, if the camera is in free running mode (internal clock) then the strobe fires continuously when the strobe is turned on, and the strobe is not dependent on the camera being in "live" mode.

I'd like to make the strobe signal into a pulse that is active only during an acquired frame. I can approximate this by issuing two commands ("strobe-on" and "live-start") one after another; however, it would be really nice (for me anyway) if the stobe pulses were an exact one-to-one relationship with acquired frames.

I think I understand the problem, and I believe the answer is that they're just independent of one another. However, if I'm an overlooking something, please let me know.


Tim Gee

Stefan Geissler
April 11, 2007, 07:59:36

I suppose, IC Imaging Control 3.0.4 is compliant to your requests. The strobe properties have been extended. Please have a look at:

April 11, 2007, 12:54:39

Thanks. That gives me some options for shaping the strobe pulse that I didn't know about.

However, what I was hoping for was a pulse that only fired when the camera was in "live" mode, so I'd have exactly one pulse per frame stored in memory. Currently, it appears the strobe is controlled independently of the "live" command.



April 11, 2007, 14:00:00
I think I may have a simple solution to get the one-to-one frame/pulse agreement that I wanted. That is to turn off the clock while the two commands are issued. To be specific:

1) Turn off internal trigger
2) Issue "strobe-on" command
3) Issue "live" command
4) Turn on internal trigger

Stefan Geissler
April 12, 2007, 14:10:38
Hi Tim,

Sorry, I forgot, you may need another firmware in your camera. Could please send me your cameras serialnumber to support@imagingcontrol.com?

April 24, 2007, 16:44:14

The new firmware helped.

I found that my idea for turning off and on the internal clock didn't work. The software returned errors (fortunately) letting me know that I couldn't modify the trigger while live acquisition was enabled.

However, after installing the new firmware, I found that the strobe wasn't active outside the live acquires, so that did what I wanted.

I'm chasing one more thing along these lines. I'm trying to match up the number of frames that I receive in memory (via the Directshow Transform hook) and the number of strobes fired. I found that often the number I counted in the Transform function was less than the number of strobes fired. Also, at the time there was some jitter appearing in the display. I've tried to associate this jitter with some sensitivity to my firewire power source - that is when I use a laptop, PCMCIA firewire card, and external firewire bus power. I'm not sure if the missed frames were caused by camera glitches, Windows/Directshow skipping frames, computational resources, or some combination. What worries me a bit, also, is how to know if I dropped any frames.


Stefan Geissler
April 24, 2007, 17:03:34
Hi Tim,

You may get more strobes than images (possibly) if the exposure time is too long. Your trigger frequency should not be too high.
I am very sorry, but I never worked with Directshow Transform hook, thus I have only a vague imagination about how you count images and strobe pulses.