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How fast with flash?

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Anonymous
August 12, 2005 10:57:00 PM

Archived from groups: rec.photo.digital (More info?)

Hi All,
I've read about how many shots a dslr camera can take in succession.
How many can this same dslr take in succession using the built in flash.
Are you limited to the flash's recharge rate? Do external flashes
recycle faster? This seems to be a limiting factor on my P&S HP 945. I
was wondering how this works on a Canon or Nikon?
Paul

More about : fast flash

Anonymous
August 12, 2005 10:57:01 PM

Archived from groups: rec.photo.digital (More info?)

Yes, you'll still be limited by the flash.

You can get external battery packs for most good flashes that speed up
the flash cycle.

I think the idea is, you'll not be using a flash on anything in sports
which is the venue that really neccessitates a high frame rate.

Wouldn't it be nice to have a flash with a built in ultra-capacitor? Or
three constantly charging with a wired battery pack.... Wonder If I
could patent one... hmm.

Correct me if I'm wrong. I'm always up for a flaming, I mean.. *cough*,
learning experience.
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Anonymous
August 12, 2005 11:18:42 PM

Archived from groups: rec.photo.digital (More info?)

Actually according to the info from Howstuffworks.com, ulltracapacitors
can hold their charge for weeks, and keep 10X the longevity and power
than batteries vs. volume, all while providing rapid charge and
discharge.

The current system is always waiting for the next. The good is the
enemy of the best. I think though, that a sytem built entirely on
Ultracapacitors on the charge and discharge side of the flash should
theoretically be able to charge the flash or discharge side of the unit
due to lower impedence. Of course, this is limited by the tranformer
getting the power up to above 1000 watts in the discharge capacitor.

I love the internet. You can find out almost anything if you look hard
enough.

Actually, if they really can hold their charge for weeks, then why not
just remove the transformer to the charger, install a large
supercapacitor in the flash, charge it up to the 1500w range full time,
and call it a day? Then you could use a small battery, or camera fed
power to control the flash electronics as the wattge just wouldn't be
compatible.... hmm...
Anonymous
August 13, 2005 12:18:37 AM

Archived from groups: rec.photo.digital (More info?)

On 12 Aug 2005 16:05:34 -0700, wavelength wrote:

> Wouldn't it be nice to have a flash with a built in ultra-capacitor? Or
> three constantly charging with a wired battery pack.... Wonder If I
> could patent one... hmm.
>
> Correct me if I'm wrong. I'm always up for a flaming, I mean.. *cough*,
> learning experience.

It depends on why you think an ultra-capacitor would help. It
takes a *lot* of current to charge capacitors quickly. If a fully
charged ultra-capacitor had enough capacity to provide a dozen or
more "full power" flashes I suppose it wouldn't really matter if it
took several minutes to fully charge - as long as the camera could
be used while charging. But that might then also require much
larger batteries, since zooming and focusing also make large demands
on the battery. And although I'm not too familiar with
ultra-capacitors, if they have the relatively high leakage rate that
most large electrolytic capacitors have, that would also waste
battery power.

I think the current (!) solution used by "pro's" that you
mentioned (external battery pack) is more practical. Those that
don't need this feature don't have to pay for it. And for those
that do, since the extra bulk and weight is external, the camera
would remain more convenient to carry most of the time when rapid
flashes aren't needed. Something like a Quantum Turbo is nice and
quick. As low a 1 second recycle time for full power flashes, and
much shorter times at reduced power for rapid bursts. If that's not
fast enough try one of Lumedyne's products. The say that their VHUX
UltraMegaCycler is "acclaimed in paparazzi and press photo circles"
and allows for 0.7 sec. recycling of up to 400 full power flashes
per charge. It works with many Canon, Metz, Minolta, Nikon, Sunpak
and Vivitar external flashes. Using Nikon as an example, it works
with 9 models, ranging from my old SB24 to the SB800, but for
whatever reason, the SB600 isn't listed. I hope that it won't be
necessary for me to repeat this tomorrow. <g>
Anonymous
August 13, 2005 3:08:22 AM

Archived from groups: rec.photo.digital (More info?)

On 12 Aug 2005 19:18:42 -0700, wavelength wrote:

> Actually according to the info from Howstuffworks.com,
> ulltracapacitors can hold their charge for weeks, and keep 10X
> the longevity and power than batteries vs. volume, all while
> providing rapid charge and discharge.

Sounds interesting. If they really have greater power density
than even lithium batteries then there'd be no need to continue
using batteries. But the 'supercap' batteries would need to have
rugged protective cases to prevent them from the danger they'd pose.
And I wonder how many charge/discharge cycles they'd have, and
whether (like lithium rechargeables) they'd only be good for 2 or 3
years?


> Actually, if they really can hold their charge for weeks, then why not
> just remove the transformer to the charger, install a large
> supercapacitor in the flash, charge it up to the 1500w range full time,
> and call it a day? Then you could use a small battery, or camera fed
> power to control the flash electronics as the wattge just wouldn't be
> compatible.... hmm...

1500w whats? 1500 watt hours?

The commercial Lumedyne product I mentioned stated that it was
used similarly. The flashes continue to use their regular AA
batteries while the ultrapower battery is used just for the flash.
The big difference being that it's an external lead weight, while
(presumably) the ultracapacitor in the flash would be relatively
small and not weigh too much. It'll still need a fairly hefty
'charger'.
Anonymous
August 13, 2005 3:26:37 AM

Archived from groups: rec.photo.digital (More info?)

Paul Schilter wrote:
> Hi All,
> I've read about how many shots a dslr camera can take in succession.
> How many can this same dslr take in succession using the built in
> flash. Are you limited to the flash's recharge rate? Do external
> flashes recycle faster? This seems to be a limiting factor on my P&S
> HP 945. I was wondering how this works on a Canon or Nikon?
> Paul

If the flash is not working at full power output, it may be able to
repeat flash a number of times. This effect is often used for pre-flash to
reduce red eye.

--
Joseph Meehan

Dia duit
Anonymous
August 13, 2005 4:25:53 AM

Archived from groups: rec.photo.digital (More info?)

Paul Schilter <paulschilter@nospamcomcast.net> writes:

> Hi All,
> I've read about how many shots a dslr camera can take in
> succession. How many can this same dslr take in succession using the built in
> flash. Are you limited to the flash's recharge rate? Do external flashes
> recycle faster? This seems to be a limiting factor on my P&S HP 945. I was
> wondering how this works on a Canon or Nikon?

Generally yes you have to wait for the flash to recharge, though some cameras
like my E-1 can be set to fire even if the flash isn't ready (of course you
will get a dim picture, and you also need a TTL flash so the camera knows when
the flash is ready).

Some external flashes recycle faster. In addition, if you really need faster
recycle speeds, with the high end flashes, you can get a high voltage battery
pack to make the recharge much faster. However, the speed comes at a cost,
namely the flashes and batteries are expensive. If you need lots and lots of
flashes, you probably should be thinking about using studio strobes, instead of
hot-shoe flashes -- I burned out a flash last year because I was using it in
continous mode for about an hour and a half (the batteries were too hot to
handle when I changed them in the middle of the shoot).

As an example, on my E-1 with my Promaster flash, I turned off the room lights,
and put the camera in continous mode. The first two shots went off fairly
quickly, and there was about 4-5 seconds between shots while the flash
recharged.

--
Michael Meissner
email: mrmnews@the-meissners.org
http://www.the-meissners.org
Anonymous
August 13, 2005 10:06:25 AM

Archived from groups: rec.photo.digital (More info?)

Michael and all,
Thanks for that info, I have a much better sense of the relationship
between camera and flash in the dslr world.
Paul


Michael Meissner wrote:
> Paul Schilter <paulschilter@nospamcomcast.net> writes:
>
>
>>Hi All,
>> I've read about how many shots a dslr camera can take in
>>succession. How many can this same dslr take in succession using the built in
>>flash. Are you limited to the flash's recharge rate? Do external flashes
>>recycle faster? This seems to be a limiting factor on my P&S HP 945. I was
>>wondering how this works on a Canon or Nikon?
>
>
> Generally yes you have to wait for the flash to recharge, though some cameras
> like my E-1 can be set to fire even if the flash isn't ready (of course you
> will get a dim picture, and you also need a TTL flash so the camera knows when
> the flash is ready).
>
> Some external flashes recycle faster. In addition, if you really need faster
> recycle speeds, with the high end flashes, you can get a high voltage battery
> pack to make the recharge much faster. However, the speed comes at a cost,
> namely the flashes and batteries are expensive. If you need lots and lots of
> flashes, you probably should be thinking about using studio strobes, instead of
> hot-shoe flashes -- I burned out a flash last year because I was using it in
> continous mode for about an hour and a half (the batteries were too hot to
> handle when I changed them in the middle of the shoot).
>
> As an example, on my E-1 with my Promaster flash, I turned off the room lights,
> and put the camera in continous mode. The first two shots went off fairly
> quickly, and there was about 4-5 seconds between shots while the flash
> recharged.
>
!