power pack for 7D and Canon 580 \ex flash

[Bill Yeung]

I do sport photography and rely on flash in indoor rink, and use a lot of 8 fps for capturing figure skating.
Even though 580 can have high speed sync. Seems that it just cannot re-charge fast enough.
Seeing from Canon battery pack to Quantum power pack.
want to ask friends here your perference and experience.

one review said Quantum has problem in communicating with 580EXII.

Advise, please.

thanks

Bill

[Colin Southern]

Hi Bill,

Canon make a high-voltage accelerator called a CP-E4 that plugs into the side of the unit. It basically feeds 380 volts straight into the unit so that the flash doesn't have to create it from the internal AA cells. You can also configure the flash to use BOTH the internal and external power sources to generate the voltage, which is faster still.

I've got 4 of them, but don't use them very often. Off memory I think I was able to get continuous firing at 10 fps with the flash set to no more than 1/8th power (you'll want to switch on the custom setting for quickflash too). The downside is that it's pretty hard on the flash, and it's not hard to cause overheating (the 580EX II has over-temp protection though).

Another approach is to use what's called the "fake battery" approach where the 4 AA batteries are replaced by an adaptor (from Quantum) and the unit is then powered from a lead-acid 6 volt power source (AA batteries work well initially, but recycle times drop as battery capacity diminishes).

Hope this helps.

[Bill Yeung]

The Quantum power pack attracted me as:
I only do indoor, family or figure skating shots.
AA battery just doesn't last very long ( an hour shot easily comes up to 3 hundreds of shoot and all of them need flash!) indoor ice rink.
AA battery problem is I don't have much idea how many power left from the last shooting. If I play safe and use new AA every occasion, then will be lots of half power AA battery left!!!
LIke using the camera battery, I normally recharge it before a shooting occasion.
that's why I look into the rechargable power pack and saw lots of wedding photographer recommend it.

thanks for more knowledge about the accelerator.

Bill

[rpcrowe]

Consider using rechargeable Eneloop batteries for an AA battery use. You could have a pocketfull of AA Eneloops and replace those in your flash at any time without worrring about wasting money on partially used batteries. The Eneloops generally provide longer life and a more stable recharge times than do batteries such as Energizer...

There are some external battery packs available which are compatible with your flash. If I selected one which was powered by AA batteries, I would opt for Eneloops...

http://www.ebay.com/itm/External-Fla...item4d035a168b

http://www.ebay.com/itm/New-Godox-PB...item564e927313

The heating up of the flash unit could propose problems. A second flash unit would minimize this. You could use a bracket like the Stroboframe Camera Flip and mount two flashes. Switching back and forth between flashes might be a PITA but, it would solve the overheating problem...

OTOH: You might consider a Quantum Flash Unit. They are pricey but, are aimed at what you are doing. http://qtm.com/

[Colin Southern]

Possibly a better choice for you would be an Al Jacobs Black Box

http://www.aljacobs.com/my-products/

I've got a couple of them and they work really well.

If nothing else, have a good look through the site -- he's quite a humourist!

[Bill Yeung]

thanks, you folks are so great, that's why i visit other forum to view reviews, photos while already start my question here.
thanks for giving three directions:
Quantum seems to be the toughest but how come I rarely see people use it in Canada?
eneloop rechragable batteries seems to be the least expensive way, while I only need a power pack for the batteries.
Aljacobs offer another option.
Good start as I can view more you tube around these product and see how it goes ..
again, really appreciate all of you who shared your experience.

thanks

Bill

[Colin Southern]

Hi Bill,

Some closing thoughts ...

- The Quantum approach has a reputation for being hard on the flashes -- a bit like running a turbo at maximum boost.

- The Enloop batteries are pretty versatile - but - depending on how much you're asking from them, the recycle times will drop off as their charge drops. This may or may not be significant.

- The Al Jacobs approach is nothing more than a Gel-cell 6v battery - if you want to "do it on the cheap" then just order the adaptor from Quantum (I forget the part number, but can find it for you pretty quickly if you want) and then make it yourself if you're handy with a soldering iron (it's just a couple of wires that connect the battery to a socket via a switch).