Why dont studio strobes use speedlight technology ??

Hodders

Hodders

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Just occurred to me as I looked at the shots from my latest childrens portrait session.

Yet again some of the jumping about shots suffer from motion blur due to the flash duration from my studio strobes.

Speed lights have much shorted flash durations.

Why don't studio strobes use speed light electronics/flash tubes to get the shorter duration ?
 
Because it's horrifically expensive to use IGBT technology for high powered studio flash heads.

And, so far at least, those manufacturers who have done it haven't managed to get anywhere near as much flash energy as the W/s rating indicates - typically they are about a stop down from the expected figure, which means that a head rated at say 400Ws only produces about as much power as you would normally get from a 200Ws flash.

But watch this space, because technology is moving on and there will be viable IGBT flashes at reasonable prices available soon...
 
Hodders said:
Just occurred to me as I looked at the shots from my latest childrens portrait session.

Yet again some of the jumping about shots suffer from motion blur due to the flash duration from my studio strobes.

Speed lights have much shorted flash durations.

Why don't studio strobes use speed light electronics/flash tubes to get the shorter duration ?
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It's a good question, and it may come, but...

As Garry says, current examples of IGBT-type studio heads are down on power Ws for Ws compared to conventional studio heads. One solution might be to effectively combine say four hot-shoe type guns in one head, and that could be affordable at Yongnuo prices and give around a true 400Ws of light.

The drawback is really fast durations would only be available at much lower power outputs. And it's a small market where those that want this approach can quite easily gang four (or more) hot-shoe guns together now. The biggest advantage here IMHO, is that you can also get decent power using high speed sync, like Dave Black here, using eight hot-shoe guns http://www.youtube.com/watch?v=xNDAINwhTWU And auto-TTL exposure control.

The other thing is that conventional studio head technology is quite capable of much faster durations than some/most. Elinchrom A-heads for example, or most Profotos, or Bowens Gemini Pro. Leaving aside the question of what t.5 duration measurements actually mean compared to shutter speeds, you can get a true 1/1500sec out of them quite easily, and at max power.

Fastest regular/affordable studio heads I've tried are Elinchrom BX250Ri. I measured them at 1/1300sec on full power, down to 1/900sec at min - that's quick enough for most things, and about 2-3x faster than most entry level jobbies.
 
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Generally, the more powerful they are, the longer the pulse of light will be.

Flash tubes are connected directly to the high voltage capacitor but they do not start to conduct until the xenon gas inside is ionised by a trigger pulse. When this happens, the tube is basically a short circuit across the capacitor discharging it in a very short time. When it is fully discharged, the xenon gas is no longer ionised and the tube goes back to its non conductive state allowing the capacitor to charge up again.

A higher powered flash will have a larger value of capacitor which stores more energy. This takes longer to discharge leading to a longer pulse time.

The technologies are the same but on different scales although what I described above is a very basic flash which outputs at full power each time.

Modern flashes use a couple of thyristors to stop the current flowing when enough light has been output as decided by either an on flash sensor or TTL interface. This has the added advantage of leaving some charge in the capacitor which will reduce its next charge up time.


Steve.
 
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Triggaaar said:
Annoying isn't it.

Is the Elinchrom Style RX, with a flash duration of 1/2850s (300W) or 1/2050s (600W) any good? Or is that still too slow?
http://www.elinchrom.com/product/Style-RX-300.html


Or the Bowens GeminiPro, with flash duration as fast as 1/2400s:
http://www.bowensdirect.com/index.php/compact-flash/geminipro/gemini-500pro.html
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I've not tested those, but rule of thumb suggests that a claimed t.5 time should be multiplied by 2-3x to get an equivalent of real shutter speeds in terms of action stopping. It's only a rough guide, and would put all those heads around 1/1000sec, which is probably just fast enough.

T.5 times get longer as the power is turned down though. Generally speaking, less powerful heads with smaller capacitors are faster.

1/1000sec won't freeze all fast movement, but it's usually the extremities like hands and feet that move fastest and that doesn't look too bad with a bit of blur, so long as faces are sharp. Sometimes a bit of blur actually looks better.
 
I agree with this, and personally often like to see a bit of blur.

If you really must have extremely short flash durations then your choices, at present, are extremely limited - hotshoe flashguns or the Alien Bees Einstein both have extremely short t.1 times at low power.
 
HoppyUK said:
I've not tested those, but rule of thumb suggests that a claimed t.5 time should be multiplied by 2-3x to get an equivalent of real shutter speeds in terms of action stopping. It's only a rough guide, and would put all those heads around 1/1000sec, which is probably just fast enough.

T.5 times get longer as the power is turned down though. Generally speaking, less powerful heads with smaller capacitors are faster.

1/1000sec won't freeze all fast movement, but it's usually the extremities like hands and feet that move fastest and that doesn't look too bad with a bit of blur, so long as faces are sharp. Sometimes a bit of blur actually looks better.
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Indeed, so look at the RX300 and Gemini 500Pro, for 1/2850 and 1/2400 (or 1/2900, depending on which spec you read). That's probably a lot faster than you currently have, and more to the point, if you read reviews on them, people say they do freeze action.

And you only really need one, for your key light.
 
Triggaaar said:
Indeed, so look at the RX300 and Gemini 500Pro, for 1/2850 and 1/2400 (or 1/2900, depending on which spec you read). That's probably a lot faster than you currently have, and more to the point, if you read reviews on them, people say they do freeze action.

And you only really need one, for your key light.
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You asking or telling? :thinking:
 
Triggaaar said:
Does that mean those lights are not suitable for you, or that you'd need more than one?
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LOL Sorry Mike, I thought you were asking the question in post #7. I am not the OP :D
 
HoppyUK said:
I am not the OP :D
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Oh yes, so you're not. Different names, with different letters, pronounced differently :)

LOL Sorry Mike, I thought you were asking the question in post #7.
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Post 7 was a question, but in post 10 I was confused and thought you were the OP, so it was a suggestion :)

Re the Paul Buff Einsteins - they aren't easily available over here, and the support for them over here is non existent, so I'd give those a miss unless they're the only thing that do the job.
 
Garry Edwards said:
Because it's horrifically expensive to use IGBT technology for high powered studio flash heads.

And, so far at least, those manufacturers who have done it haven't managed to get anywhere near as much flash energy as the W/s rating indicates - typically they are about a stop down from the expected figure, which means that a head rated at say 400Ws only produces about as much power as you would normally get from a 200Ws flash.

But watch this space, because technology is moving on and there will be viable IGBT flashes at reasonable prices available soon...
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Garry, I've read that speed lights are less colour consistent than studio heads because of the way the power is controlled. Is that true?
 
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gfinlayson said:
Garry, I've read that speed lights are less colour consistent than studio heads because of the way the power is controlled. Is that true?
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Not really. Most speedlites have very good and consistent colour. They do get a little cooler at low power settings, but it's hardly noticeable. You get more colour polution from the surroundings than from the flash itself.

Studio heads are different. Conventional ones get more yellow at lower power settings and it's noticeable, but rarely an issue. IGBT-type studio heads are the worst for colour and though they use the same technology as speedlites, they don't seem to be as well controlled. Of the ones I've used, they can get significantly blue at lower power outputs. Again, not a deal breaker in itself, but if you have two of these lights on the same subject at different power settings it can be a problem. Probably unlikely in practise though.
 
gfinlayson said:
Garry, I've read that speed lights are less colour consistent than studio heads because of the way the power is controlled. Is that true?
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Yes, but let me qualify that...

All that I've personally tested is my Nikon SB-800, a couple of older Nikon flashes and some generic flashguns. I haven't tested the SB-900 and I haven't tested any of the Canon products, simply because I don't have any.

The consistency, flash to flash, is spot on. The problem I found is that as the power is turned down, the colour becomes increasingly colder (more blue).

The reason for this is obvious. At full power, the flash discharge is complete and the camera records all of the light emitted by it. This includes both the blue colour of the start of the flash and the red colour at the end of it, which balances out nicely. As the power is turned down, the flash pulse is quenched, and at some point only the very start of the flash pulse, which is very blue, is 'used'.

On most of the flashes I tested, the colour changed by 1000K.

Of course, this problem may not exist in all flashes - Richard (Hoppy) says that the Canon ones are OK.

The problem is definitely there with the Alien Bees IGBT light (Einstein) but they have a clever solution for it, a mode that progressively adjusts the colour temperature as the power is reduced. And I happen to know about another, brand new IGBT light that will be available shortly that also gives consistent colour regardless of the power setting.
 
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