Flashgun vs studio head

[treeman]

I'm not up to date with flash stuff at all these days, but I here a lot of talk about strobist this and that, with speedlites etc, and was wondering in terms of power how a top end battery flashgun, compares in power to studio heads.

 

[HoppyUK]

Hot shoe guns get by by firing a concentrated beam directly at the subject, and nowhere else, so they are very efficient with the small amount of light they produce. But when you bounce them they run out of power, and when you ask them to fill even a small softbox, then can only just manage at short range.

It can be done however, helped by the high ISOs that are possible with digital, as the stunning strobist results we often these days testify. But there was a picture of strobist guru Joe McNally posted on here recently, battling against daylight with seven Nikon SB900s lined up together

Watts and joules etc are measurements of electricity, which doesn't always translate to light ouput, but I think I read recently that a hot shoe gun does 70J or something but I may be wrong there. The only measurement of light output I know of is the Guide Number but that too is subject to all sorts of variables and comparing like with like accurately is very hard.

Bottom line is hot shoe guns will do the job, with care and with limitations. But four AA batteries cannot compete with mains power (a bit like a torch vs mains bulbs) and recycle times are very slow for serious portraiture.

 

[david1701]

each have different purposes hotshoe guns are great for working in close spaces or in the dark but as hoppy aays they can't outdo the midday sun

in my book you need to know both (i have both in my room atm) as each are very useful in their own way. i mean i was in my sisters shop with my camera bag and she asked me to do some quick pics. the ambient was hideous so i shoved a speedlight on full power as high as pos bounced off the ceiling and the pictures were a thousand times better, bit of burn around the uplighters to make them look real that you can control with the shutter

imo the flexibility of speedlights makes them worth thier wieght in gold

 

[Terrywoodenpic]

Flash guns are jack of all trades, and excel as fill light.
Studio flashes are just that, and for formal set-ups can't be bettered.

However do not forget studio flashes can be taken outside and used with large battery packs.(and or Generators) You will see them augmented with large reflectors on most fashion shoots.

 

[classcams]

Joules is not used nowadays, it is now called Watt-sec. Same answer though. The formula is 1/2*C* v^2 (c is in farads). So this limits the size of the capacitor in onboard or hotshoe mounted flashguns. Therefore the power of these guns is small.The voltage can easily be obtained with a built in oscillator. I have a small flashgun that takes 2 AA batteries, and the trigger voltage is 400 volts. The power of these guns is quite low compared to a studio flash which is about 250 watt-sec.

 

[david1701]

Joules is not used nowadays, it is now called Watt-sec. Same answer though. The formula is 1/2*C* v^2 (c is in farads). So this limits the size of the capacitor in onboard or hotshoe mounted flashguns. Therefore the power of these guns is small.The voltage can easily be obtained with a built in oscillator. I have a small flashgun that takes 2 AA batteries, and the trigger voltage is 400 volts. The power of these guns is quite low compared to a studio flash which is about 250 watt-sec.

but the amount of lecky involved doesn't always relate to the amount of light you get out

also watt-seconds are joules (P*T=E)

 

[Garry Edwards]

Joules is not used nowadays, it is now called Watt-sec. Same answer though. The formula is 1/2*C* v^2 (c is in farads). So this limits the size of the capacitor in onboard or hotshoe mounted flashguns. Therefore the power of these guns is small.The voltage can easily be obtained with a built in oscillator. I have a small flashgun that takes 2 AA batteries, and the trigger voltage is 400 volts. The power of these guns is quite low compared to a studio flash which is about 250 watt-sec.

In fact, it has always been called Joules except in the U.S., they prefer the term Watt seconds (Ws) not Watt-sec.

The energy storage of studio flash heads varies enormously, from around 30J to around 1500J for mono heads, and can be much greater for generator-powered heads, they are not all 'about 250' although many of those popular for small studio use are. I think I'm right in saying that most hotshoe flashes are around 60J or less, although a few are slightly more powerful

 

[classcams]

In fact, it has always been called Joules except in the U.S., they prefer the term Watt seconds (Ws) not Watt-sec.

The energy storage of studio flash heads varies enormously, from around 30J to around 1500J for mono heads, and can be much greater for generator-powered heads, they are not all 'about 250' although many of those popular for small studio use are. I think I'm right in saying that most hotshoe flashes are around 60J or less, although a few are slightly more powerful

My Solaflash manual calls it joules (watt/sec). Does it matter? Of course energy differs from different models, small and large. Having made several different models, limited only by the lack of parts obtainable in this country.I cannot see why you correct yourself so much as above I have had so many shocks in the past, my hair is now permanently vertical. Believe me DC is ten times worse than AC. At least one gets a brief respite every 25 milliseconds with AC.

 

[classcams]

but the amount of lecky involved doesn't always relate to the amount of light you get out

also watt-seconds are joules (P*T=E)

By lecky, do you mean electric? I always remember as a child, all the houswives would say "The lecky man is due today". Oops I dropped a clanger above. It should be 10 milli seconds.

 

[kalibre]

Got both, love both but I must say once the novelty has worn off of the studio stuff I reach for the speedlights because of portability and quick setup. Of course there are limitations but most can be addressed or worked around.

If I was starting out again I'd go speedlights first until I knew why I would need studio lights or decided I didn't!

 

[treeman]

Thanks folks, pretty much what I thought. I was just wondering whether somehow someone was making mega powerful flash guns I hadn't heard of!

 

[david1701]

By lecky, do you mean electric? I always remember as a child, all the houswives would say "The lecky man is due today". Oops I dropped a clanger above. It should be 10 milli seconds.

yeah apparently I werent brought up proppa