Can it freeze action ?

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testbloke

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Good afternoon. Looking to buy my studio lights as soon as funds allow, had just about decided between Elinchrom D-Lite RX4 (when they actually become UK stock) and Lencarta Ultrapro 300.
However, one thing I was keen to offer clients was the ability to freeze "action", as we will be taking dance school images of kids in costume it would be nice to offer some shots of the kids in movement.
On both the above mentioned kits I start to worry but am unsure exactly how to calculate ...
Example, manufacturer quotes T0.5 of 1/1200th
this roughly gives T0.1 of 1/400th ?
However, this will be at full power ? How does this (roughly) decay with half power, quarter power etc. ?

I don't want the alternative technology employed in Paul C Buff etc. (or the price and lack of support in EU), am I better off looking at used, something like the Rx300 which quote T0.5 at 1/2850th ?

Many TIA
 
t.0.5 roughly equates to an equivalent shutter speed of somewhere between 2 and 3 times as long the stated t.5 time.

Equivalent shutter speed is probably a more meaningful expression of speed than a t.1 time.

There is in fact no more accurate or precise way of expressing it, the problem is that although t.5 is a precise measurement, as the power of the flash declines over time, the colour of the light becomes more and more red in colour. At some point, the colour ends up in the non-visible part of the spectrum (somewhere near infra red) and doesn't affect the shot - But if you were shooting on infra red film or on an infra red digital camera, it would effect it enormously. Conversely, if you were shooting on the old orthocromatic film it wouldn't affect it at all. As not all digital cameras are equal, the apparent flash duration can vary.

The fact of the matter is that if you need really short flash durations then you need to use IGBT flashes and accept the low effective power and higher cost.
 
Gary, thanks for response. Just trying to get to a worst case effective speed for these lights.
"Equivalent shutter speed is probably a more meaningful expression of speed than a t.1 time." Accept your point, but at the end of the day we are still at the third of T.5 time (roughly).
As already stated, don't want to go down IGBT route, this is not olympic sprinters I am trying to freeze, just kids jumping, turning etc. and I can live without one kidney but cannot sell both at the moment ! (scraping funding together).
What would be the equivalent shutter speed (roughly) of an ultrapro 300 at half power and quarter power ?
 
Garry Edwards said:
t.0.5 roughly equates to an equivalent shutter speed of somewhere between 2 and 3 times as long the stated t.5 time.
Click to expand...

For many types of light (including the 2 listed). For some others the relationship breaks down. As Facebook would say "it's complicated".

Not sure I understand the comment about IGBTs and kidneys. Some IGBT lights are available in the EU for less than the cost of Elinchroms.
 
What it comes down to. I reckon I need equivalent of 1/200th to ensure that the kids moving can be frozen. I do not expect to have an ultrapro 300 working at more than half power to light this (total three ultrapro 300).
All lights will normally be about five feet from subject (keylight less when used).

Can the ultrapro 300 achieve this ?
 
JonathanRyan said:
For many types of light (including the 2 listed). For some others the relationship breaks down. As Facebook would say "it's complicated".

Not sure I understand the comment about IGBTs and kidneys. Some IGBT lights are available in the EU for less than the cost of Elinchroms.
Click to expand...

Jonathon, I'm talking Elinchrom D-Lite RX kit here, roughly £575 including stands, softboxes etc. for two heads.
 
testbloke said:
Jonathon, I'm talking Elinchrom D-Lite RX kit here, roughly £575 including stands, softboxes etc. for two heads.
Click to expand...

Ah - I'd missed that Elinchrom had rearranged their letters again ;) (Real) RX kit is a little more.

Even so, IGBT isn't far off that money.
 
testbloke said:
What it comes down to. I reckon I need equivalent of 1/200th to ensure that the kids moving can be frozen. I do not expect to have an ultrapro 300 working at more than half power to light this (total three ultrapro 300).
All lights will normally be about five feet from subject (keylight less when used).

Can the ultrapro 300 achieve this ?
Click to expand...
It's difficult to answer this, because the UltraPro models have now been revised and have more effective power and shorter flash durations...
Let me do some tests on the new models, I can then give you a definitive answer.
 
The 500BXRi has a t.5 of time of 1/1558 (roughly 1/500th) and even that struggles to freeze action like someone just jumping.
 
Garry Edwards said:
It's difficult to answer this, because the UltraPro models have now been revised and have more effective power and shorter flash durations...
Let me do some tests on the new models, I can then give you a definitive answer.
Click to expand...

Very much appreciated.
 
EOS_JD said:
The 500BXRi has a t.5 of time of 1/1558 (roughly 1/500th) and even that struggles to freeze action like someone just jumping.
Click to expand...

Jim, I have a chance of used RX300's at the moment but need receivers as well so going to cost a good wee bit more and are two years old.
If these kits cannot cut it then I will probably go for the RX300's which have a quoted T.5 time of 1/2850, definately be quick enough.
 
Somebody will be along in a minute to sell you some magic triggers..... ;)

Personally, I like 1/10,000 duration :D
 
testbloke said:
Jim, I have a chance of used RX300's at the moment but need receivers as well so going to cost a good wee bit more and are two years old.
If these kits cannot cut it then I will probably go for the RX300's which have a quoted T.5 time of 1/2850, definately be quick enough.
Click to expand...

The RX300s are the dogs wotsits. Basic set of trigger/receivers should work fine although ideally you want the skyports (but cheap ebay ones would work fine for a bit). The sync speed of the trigger is not important.
 
consider a couple of speedlights on a stand

consider the SB800 for example

1/1050 sec. at M 1/1 (full) output
1/1100 sec. at M 1/2 output
1/2700 sec. at M 1/4 output
1/5900 sec. at M 1/8 output
1/10900 sec. at M 1/16 output
1/17800 sec. at M 1/32 output
1/32300 sec. at M 1/64 output
1/41600 sec. at M 1/128 output
 
testbloke said:
What it comes down to. I reckon I need equivalent of 1/200th to ensure that the kids moving can be frozen. I do not expect to have an ultrapro 300 working at more than half power to light this (total three ultrapro 300).
All lights will normally be about five feet from subject (keylight less when used).

Can the ultrapro 300 achieve this ?
Click to expand...

I assume that's a typo. You certainly need a lot faster than 1/200sec to freeze dance movement. I would have said a 'real' 1/1000sec minimum, and preferably nearer 1/2000sec. On the other hand, so long as faces are sharp, faster moving hands and feet can look quite good with a bit of blur.

As Jonathan says, it's complicated, but without going into all the detail, I've tested a lot of popular heads for Advanced Photographer magazine and I would recommend Elinchrom BX-250Ri. That's easily the fastest affordable head this side of Profoto and its claimed t.5 duration of 1/2762sec at full power checked out at around 1/1300sec in terms of shutter speed equivalents, down to 1/900sec at minimum. BX-500Ri was 1/900sec to 1/700sec. They're also very nice units.

In the same tests, Lencarta's EP600 did 1/500sec at max down to 1/350sec at min, and the EP300 1/600sec to 1/400sec. If you want a back issue, it's Jan 2012 edition (also see Dec 2011 edition, that has more entry level heads, including Elinchrom D-Lites).

To a certain extent, these measurements are subjective because that's the only way you can assess it - by shooting a fast moving subject (powerful fan) with continuous light at real shutter speeds, and then comparing the blur against the flash images. The problem is the nature of the blur is different with flash as the total flash burn time is a) long, like 1/200sec, b) that doesn't change much at all at different powers, and c) it's the height of the peak that gives the 'impression' of a shorter effective exposure times, and that's what changes at lower settings.
 
HoppyUK said:
I assume that's a typo. You certainly need a lot faster than 1/200sec to freeze dance movement. I would have said a 'real' 1/1000sec minimum, and preferably nearer 1/2000sec. On the other hand, so long as faces are sharp, faster moving hands and feet can look quite good with a bit of blur.

As Jonathan says, it's complicated, but without going into all the detail, I've tested a lot of popular heads for Advanced Photographer magazine and I would recommend Elinchrom BX-250Ri. That's easily the fastest affordable head this side of Profoto and its claimed t.5 duration of 1/2762sec at full power checked out at around 1/1300sec in terms of shutter speed equivalents, down to 1/900sec at minimum. BX-500Ri was 1/900sec to 1/700sec. They're also very nice units.

In the same tests, Lencarta's EP600 did 1/500sec at max down to 1/350sec at min, and the EP300 1/600sec to 1/400sec. If you want a back issue, it's Jan 2012 edition (also see Dec 2011 edition, that has more entry level heads, including Elinchrom D-Lites).

To a certain extent, these measurements are subjective because that's the only way you can assess it - by shooting a fast moving subject (powerful fan) with continuous light at real shutter speeds, and then comparing the blur against the flash images. The problem is the nature of the blur is different with flash as the total flash burn time is a) long, like 1/200sec, b) that doesn't change much at all at different powers, and c) it's the height of the peak that gives the 'impression' of a shorter effective exposure times, and that's what changes at lower settings.
Click to expand...

Thanks, great info. I am not trying to catch the kids dancing, it will be a white and black background, but just wanted to add a little bit of movement rather than the normal rigid pose. Flicking hair round, jumping on the spot etc.
 
testbloke said:
Thanks, great info. I am not trying to catch the kids dancing, it will be a white and black background, but just wanted to add a little bit of movement rather than the normal rigid pose. Flicking hair round, jumping on the spot etc.
Click to expand...

The last thing you want is to buy kit and then find it's not doing the job. Suggest you do some trial shots in daylight at different shutter speeds and then you'll at least have a sound base to work from.

BTW, the IGBT flashes like all hot-shoe guns and also some studio heads work completely differently. Flash durations get shorter at lower power, and they are actual, ie quoted times should be the same as shutter speed equivalents. Only caveat is at full power, before the IGBT circuit kicks in, they behave like studio heads so I would double just that one time to be safe.
 
Other than Paul C Buff, who should I be looking at for considering IGBT. I remember seeing oscilloscope traces for both types of lights, do understand how they work, just difficult to estimate the decay on reduced power for non igbt units.
 
testbloke said:
Other than Paul C Buff, who should I be looking at for considering IGBT. I remember seeing oscilloscope traces for both types of lights, do understand how they work, just difficult to estimate the decay on reduced power for non igbt units.
Click to expand...

Strobeam. I've had a quick look at those too and at full power, before the IGBT starts to work, durations are actually very tardy. It's only when you turn them down, from about quarter power and less, that true durations get shorter than most conventional studio heads. Thereafter durations approximately halve for every stop of reduction, very broadly in line with the durations quoted above for the Nikon SB800.

As a rule, the few studio heads around with IGBT control are not as powerful as conventional studio heads, Ws for Ws, and they can get a bit blue at low outputs. Prolly nothing you can't work around though.

I've given estimated durations for four studio heads at lower outputs above. Most other conventional studio type heads will follow a similar pattern.
 
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Was checking some old images from the studio we hire, all heads in the studio are Bowens 500 gemini. I have some shots of people jumping across the backdrop that are sharp. Looking at the spec on the Bowens the T.5 is quoted at 1/900th. The keylight would have been at approx. half power.
 
An update of sorts, I'm in the process of producing shots that prove the equivalent shutter speed of all Lencarta flashes at full, half and minimum power, and expect the whole lot to be complete and published some time on Friday. It's a big job:(
 
Garry Edwards said:
An update of sorts, I'm in the process of producing shots that prove the equivalent shutter speed of all Lencarta flashes at full, half and minimum power, and expect the whole lot to be complete and published some time on Friday. It's a big job:(
Click to expand...

Big job Gary but must be a good thing to be able to show.
With regards my setup, I hit the credit card on two rx300's to get me started, but will still be looking for a further two heads later.
 
Well, if those flash durations are accurate then they should also be pretty consistent regardless of power setting, because it's pretty easy to do this in flash generators, where there is plenty of space for a large bank of capacitors that can be switched out as required to reduce power output, rather than using a potentiometer to reduce the voltage.

I feel that Bowens are being quite brave, bringing out this new model. The market for large, heavy, expensive and powerful flash generators is now very limited, and there's plenty of competition too. I hope it works for them but I have my doubts.
 
Although I must admit, I would love a shorter flash duration when I'm photographing children. The little buggers love to jump around and unless you catch them at the top of the jump there is always motion blur.
 
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