Dual 580EXII's vs Quadra?

I've been using speedlites for strobist work for a while now and was considering upgrading to something more powerful for day time portrait work. The Quadras looks like a great system and very portable. One problem I have is the lack of a standard for comparing power outputs between strobes and speedlites. I had assumed that the quarda would be a lot more powerful (was thinking around 4 stops) than a 580EXII but according to this blog it is only just over a stop.

As I'm considering the new lastolite octa which works with a dual speedlite mount or a quadra, is there any benefit (other than recycle times) to using the quarda over two 580's?

a 580EX2 is considered to be approx. 80Ws whereas a quadra is 400Ws

dedicated flashes and the quadra have their own strengths and weaknesses.

afterall, even though I own four 580EX2 and two quadra, I have just purchased four 600EX-RT and the ST-E4-RT

why? there are things the quadra can't do anywhere near as well as a speedlite

Thanks for the reply. So do you agree with the blog I quoted in the first post that the quadra is 1 1/3 stops more powerful than a 580EXII? I'm finding it hard to justify spending over £1000 to get a single quadra and pack, when if I can get pretty much the same power output using a dual speedlite bracket.

Are two cheese sandwiches better than one ham sandwich?

You are not comparing like with like, so stop trying.

They are fundamentally different and essentially incomparable.

I have several 580exII and a Quadra. If you knew why you wanted a quadra, and its benefits, then you would not "find it hard to justify spending over £1000....."

Trailboy wrote in post #15462135
... and its benefits...

Hence me asking the question!! Perhaps you can enlighten me?

What are the differences between a studio head and a flashgun?

Got all night? Google it for many comparisons.

Power is the main reason. Want to use a softbox and balance a bright ambient, you are not going to do it with a 580.

Multiple 580s can be useful, for example, for ttl and HSS, which quadras dont offer.

Trailboy wrote in post #15462203
...Power is the main reason....

Which brings us nicely back to my original question that if the power of dual 580EXII's is about the same as a quadra then what advantages does a quadra head have over a dual speedlite setup?

as a rough estimate, one would require 5 speedlites to equal a quadra.
two speedlites on full power would be ~160Ws, somewhat less than the 400Ws of a quadra

a few pros and cons for you.

cost vs power
a single quadra blows away and speedlite
to equal a quadra in speedlites will cost and be bulky; triggers brackets, cables etc

convenience
switch on shoot

weight
not too bad with the LiON battery

quality of light
pick a modifier

robustness
not weathersealed, win for speedlite

speed
quick flash duration, a draw

frame rate
a quadra cannot do 10fps
my speedlites can

recycle
a quadra has to recharge after every fire

on-camera control
new canon system way ahead
el system ok and will trigger other el strobes


trailboy does have a point, if you can't see the need, then you probably don't have a need.

It doesnt.

Even by the above comparison, 80 w/s (but who really knows) against 400 w/s is two and bit stops, meaning you would need at least four 580ex to get the same 'w/s' output. I'd say it's probably more actually.

Bu the quadra outputs its light very differently. That 80w/s power output it usually at maximum zoom, whereas the quadras is outputting its light in almost a 360 degree orb. No hotshoe gun will ever fill a softbox like a bare headed quadra.

They are incomparable, like I said. Different tools for different jobs.

.mark. wrote in post #15462226
Which brings us nicely back to my original question that if the power of dual 580EXII's is about the same as a quadra then what advantages does a quadra head have over a dual speedlite setup?

but the power of two 580EX2 is not about the same as a quadra

never was, never will be

.mark. wrote in post #15461021
I had assumed that the quarda would be a lot more powerful (was thinking around 4 stops) than a 580EXII but according to this blog it is only just over a stop.

The blog is bogus. There are some real problems with his methodology.

Sure, you can compare Speedlites with strobes, but you have to do the comparison using both lights with the same modifier. And the results are going to vary, depending on the modifier.

Using a softbox, I compared my 580EX II to my Alienbees B1600 (640ws) and got a difference of 3.1 stops (using a flash meter at a measured distance). That puts the 580EX II at around 70ws (give or take).

The comparitive figures in the blog only work if the angle of coverage of each flash is the same. I can't find any specification for the Quadra head re angle of coverage but it looks to be quite wide. Before making definitive judgement on relative power, you'd need a bit more information. Otherwise you're in the strange situation where the Quadra is both 4 f/stops more powerful and only 1⅓ f/stops more powerful.

Two cheese sandwiches are definitely better than one ham sandwich by calorific value. Conversely, one ham sandwich is arguably better for aesthetic value. It depends on the criteria you apply. Same with w/s or GN comparisons. The w/s (a historical and virtually useless rating for photographers) takes no account of the efficiency of the flash tube converting that energy to light, nor does it consider reflector efficiency. Kind of like saying "Which is better, a cheese sandwich or an elephant".

It sounds as though your spending capacity is running somewhat ahead of your actual need.

Whortleberry wrote in post #15462265
The comparitive figures in the blog only work if the angle of coverage of each flash is the same. I can't find any specification for the Quadra head re angle of coverage but it looks to be quite wide. Before making definitive judgement on relative power, you'd need a bit more information. Otherwise you're in the strange situation where the Quadra is both 4 f/stops more powerful and only 1⅓ f/stops more powerful.

Two cheese sandwiches are definitely better than one ham sandwich by calorific value. Conversely, one ham sandwich is arguably better for aesthetic value. It depends on the criteria you apply. Same with w/s or GN comparisons. The w/s (a historical and virtually useless rating for photographers) takes no account of the efficiency of the flash tube converting that energy to light, nor does it consider reflector efficiency. Kind of like saying "Which is better, a cheese sandwich or an elephant".

It sounds as though your spending capacity is running somewhat ahead of your actual need.

Unless you're a veggie. Different strokes....

Will the Quadra be powerful enough for you? 400w/s won't necessarily over power daylight if you're using modifiers and can't get as close as you need to be to the subjects or if you're shooting multiple subjects. Will this be an issue for what you're doing?

Also, will the battery be a limitation? What's the guesstimate for number of shots at full power? Will that be enough for you of will you have to purchase another expensive proprietary battery?

Would a monolight connected to something like a vagabond mini work better for you? How many lights do you see yourself needing at one time? IIRC, the Quadra can only run two lights off of one pack.

Of course there are advantages too. It's super light and stores easily according to what I've read.

Vagabond mini is not a realistic option outside of the US.

OP is in the British Isles, like me.