430 8fps?

[Nick Pro]

Hey guys. Would a 430 be able to go off at 8fps? Or would I need to upgrade to a 580...

mark III w/ flash
http://www.youtube.com/watch?v=ze_Ywkp4fis&feature=related

Thanks!
Nick

[neil_r]

the recycle time is directly proportional to the flash output. (That is for the individual exposure not the overall Guide No.)

[PacAce]

Hey guys. Would a 430 be able to go off at 8fps? Or would I need to upgrade to a 580...

mark III w/ flash
http://www.youtube.com/watch?v=ze_Ywkp4fis&feature=related

Thanks!
Nick

Yes, the 430EX can do 8 fps at the right output setting.

[Wilt]

Yes, the 430EX can do 8 fps at the right output setting.


I have not seen guidelines, but I wonder for how many seconds you could do this, without danger of thermal overload of the flash

[Nick Pro]

Thanks guys!

Hey pac, and idea what that setting would be? The high speed sync or course and what else?

[sandpiper]

Thanks guys!

Hey pac, and idea what that setting would be? The high speed sync or course and what else?

I don't think high speed sync would be a good idea, unless you really needed to use a fast shutter speed, the extra flashes would deplete the capacitor quicker I should think.

As for other settings, it's hard to say. You want to keep the actual power usage, per shot, to an absolute minimum so a wide aperture would be useful, as would trying to keep your subject fairly close.

[poloman]

IMO you are at the edge of the envelope with this idea. If you can do it. You will probably be happier with the 580exII and a battery pack.

[PacAce]

I have not seen guidelines, but I wonder for how many seconds you could do this, without danger of thermal overload of the flash

The 430EX manual says not to shoot more than 20 continuous burst without letting the flash cool down for 10 minutes. For worst case scenario, I take that to mean 20 continuous full power bursts. So, assuming a normal recycle time of about 3 to 4 seconds, you could probably shoot continuously for about 60 to 80 seconds at 3 to 4 seconds per frame (not frames per second) before being in danger of thermal overload. But I'm sure that's not what you really meant to ask. :mrgreen: :lol:

Or, another way to look at it, if I set the flash to 1/16 power, I should theoretically be able to shoot a burst of 16 frames for 2 seconds at 8 fps and generate the same amount of heat as when I shoot only one frame at full power. So, it's not how long a burst you're shooting the flash at but how much total power you're expending when firing the flash in a burst. :)

[Wilt]

The 430EX manual says not to shoot more than 20 continuous burst without letting the flash cool down for 10 minutes. For worst case scenario, I take that to mean 20 continuous full power bursts. So, assuming a normal recycle time of about 3 to 4 seconds, you could probably shoot continuously for about 60 to 80 seconds at 3 to 4 seconds per frame (not frames per second) before being in danger of thermal overload. But I'm sure that's not what you really meant to ask. :mrgreen: :lol:

Or, another way to look at it, if I set the flash to 1/16 power, I should theoretically be able to shoot a burst of 16 frames for 2 seconds at 8 fps and generate the same amount of heat as when I shoot only one frame at full power. So, it's not how long a burst you're shooting the flash at but how much total power you're expending when firing the flash in a burst. :)

Leo,
There is an inherent ability for the flash to dissipate heat. So it might be possible, for example, to have a flash output ar 1/16 power ad infinitum until the batteries are drained, if the dissipation was faster than the heat generated at 1/16. OTOH, the heat generation might be higher than the dissipation, so there are a finite number of consecutive flashes before you need the cool off time. But there are no guideline for this type of usage, except at full power.

[PacAce]

Thanks guys!

Hey pac, and idea what that setting would be? The high speed sync or course and what else?

At 1/16 power on my 580EX II, I could easily shoot at 10 fps with my 1DmkIII for more than a second before the charge ran out. With an external power pack, I'd be able to shoot for a longer length of time. At 1/8 power, I'd still be able to shoot at 10 fps but only for a burst of 6 or 7 frames before running out of juice.

[Nick Pro]

Thanks again! Will the temperature outside have any affect on how hot it gets? Im asking because Im shooting a snowboarding contest, and its gonna be coooooooooold!

[PacAce]

Leo,
There is an inherent ability for the flash to dissipate heat. So it might be possible, for example, to have a flash output ar 1/16 power ad infinitum until the batteries are drained, if the dissipation was faster than the heat generated at 1/16. OTOH, the heat generation might be higher than the dissipation, so there are a finite number of consecutive flashes before you need the cool off time. But there are no guideline for this type of usage, except at full power.
You're right, Wilt. But shooting at full power would be the worst case because the only time for the flash to cool down is during the time it is recharging. When fired at a fraction of full power, it takes longer to discharge the total charge so the time to cool is extended by how long it takes to fully discharge the capacitor, that is, if we kept the math simple since obviously, the capacitor should be able to start charging as soon as its at less than full capacity which would then lessen the time it takes to fully charge the capacitor between bursts. Now, if the recharge time between burst is reduced significantly, then I guess discharging continuously at full power may not be the worst case scenario after all. :confused:

[PacAce]

Thanks again! Will the temperature outside have any affect on how hot it gets? Im asking because Im shooting a snowboarding contest, and its gonna be coooooooooold!
Yes, the outside temperature will affect how fast the flash cools down but by how much or if it will make a significant difference, I can't say.

[mbellot]

While its not a 430 (or 580) the manual for my Sigma 500 lists the following limits:


Mode Number of Flash Exposures
TTL, M(1/1,1/2) 15 Continuous Flash Shots
M(1/4, 1/8) 20 Continuous Flash Shots
M(1/16-1/32) 40 Continuous Flash Shots
Multi 10 CycleSo, assuming the Canon flashes are similar you would be limited to ~ 5 seconds at 1/16 in a continuous burst. And thats assuming the charging circuit can keep up.

[neil_r]

Its not the flash temp you need to worry about whenever I do this my nmh batteries start to cook

[FlashZebra]

Yes, the outside temperature will affect how fast the flash cools down but by how much or if it will make a significant difference, I can't say.
PacAce, Looks like those thermodynamics class of yesteryear still haunt, and still serve.

The temperature differential between the warmer item and the ambient is one of the fundimental aspects of heat transfer.

Enjoy! Lon

[Wilt]

Its not the flash temp you need to worry about whenever I do this my nmh batteries start to cook


OTOH it is a whole lot less expensive to replace 4AA than one 430! :)

[PacAce]

Who wants to lay odds that the flash will go before the batteries do? ;) :lol:

[Wilt]

Who wants to lay odds that the flash will go before the batteries do? ;) :lol:

I bet on the side of the flash going first. so would the guy who cooked two 580EXs before changing his ways with the third one!

[PacAce]

I bet on the side of the flash going first. so would the guy who cooked two 580EXs before changing his ways with the third one!

Yeah, I agree. If that guy created a "Warning: Don't let this happen to your flash" thread relating his eye-opening experience, I'd sticky it right away. :D

[Wilt]

Yeah, I agree. If that guy created a "Warning: Don't let this happen to your flash" thread relating his eye-opening experience, I'd sticky it right away. :D

It started in the Quantum Batteries thread,

http://photography-on-the.net/forum/showpost.php?p=4889074&postcount=1

first raising the issue with this message...

http://75.126.234.18/forum/showpost.php?p=4897537&postcount=16

and ended with message #28

[msowsun]

Hey guys. Would a 430 be able to go off at 8fps? Or would I need to upgrade to a 580...

mark III w/ flash
http://www.youtube.com/watch?v=ze_Ywkp4fis&feature=related

Thanks!
Nick

If you just want to make a video like the one you linked to, then yes it will be no problem. Just set the flash to manual at 1/64 power and have at it.

If you want to actually photograph something, then it will depend on the ISO, aperture and subject distance.

Example......My 580EX II, at 1/64 power, will light a subject at about 20' with f4, and ISO 800.