CHDK for external flash?

[rks]

Does anyone here know a lot about CHDK and its capabilities? I'm super curious if there's anyway you could hack the canons to make the internal flash fire dimly instead of full on. (And yes I understand that normally flashes fire at one brightness and the camera varies duration)

What I'm looking for is if you could do a dim on camera flash then if you shot optical strobes you would refresh faster and not drain the on camera battery.

 

[KeithG]

your description is a little confusing. the flash tube in strobes always emit the same intensity of light. the "amount" of light is controlled by having the tube "on" for different time durations.

a dim setting is just a shorter firing duration of the same light intensity. they do not have the ability to use less power, only the same power for a different time period.

most (all?) current canon cameras have the ability to manually set the internal flash "power" level (my G16 has a minimum, medium, maximum setting). if i used optical sync then i would set the internal flash level to minimum in order to conserve battery and decrease the cycle time. this feature is available as a standard setting.

do you have a specific camera in mind?

 

[sunnyboy]

CHDK is very camera specific. I've used the version for my older UW camera, a Canon A570IS. It does indeed provide control over almost every aspect of the camera - well beyond what the default software and physical buttons provide, but it's also a bit of a steep learning curve (dozens of menus to explore). I used it to give me raw+jpeg (raw was not offered on the A570) as well as a functional battery level indicator. I did not play with flash power, but am pretty sure I saw it.

And yes, flash power is a misnomer as pointed out by others here. It's really flash duration, but is usually expressed as a power %, at least many versions of chdk.

 

[rks]

I understand the duration thing and in fact referenced in my original post as you can see. What I want is brightness the ability to have the same duration and a lower brightness, without this you suffer using optical strobes

 

[KeithG]

I understand the duration thing and in fact referenced in my original post as you can see. What I want is brightness the ability to have the same duration and a lower brightness, without t
his you suffer using optical strobes

Xenon tubes do not allow this. They are on or off.
To change the brightness you need to change the size of the tube.

 

[bvanant]

Maybe I am not seeing this correctly but I think we are talking apples and orangutans. Brightness means something very specific and the OP (RPS) is not using it in the correct scientific meaning or if he is he misunderstands how a flash tube can work, but I think we all get his point. He wants to use his strobe at lower power i.e. shorter duration which will allow for faster recycling and potentially less battery usage (but this depends a lot on how the capacitor charging circuit is designed). In most modern cameras you can fire the flash at some low value like 1/64th power, I(sadly not on the A6000) and this does appear to save battery power and certainly improves cycle time.

Bill