SB 800/ SB 900 power output in watts

Started Feb 28, 2011 | Discussions
Kodak22 New Member • Posts: 13
SB 800/ SB 900 power output in watts

Just wondering how they stack up against studio flash heads. I'm guessing 100-150w.. Does anyone know?

rockjano Senior Member • Posts: 2,586
Re: SB 800/ SB 900 power output in watts

Well I would rather put it to 80-100W/s. The SB800, I don't have the SB900 but that should be the same or a little even less powerful.

The SB600 is about 60-70W/s. The SB24 is also 80-100W/s

It also depends on how you measure it but I put it into softbox and measured it against my 600W/S studio strobes with lightmeter from the same distance.

That was what I got.

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WFulton Senior Member • Posts: 2,698
Re: SB 800/ SB 900 power output in watts

Kodak22 wrote:

Just wondering how they stack up against studio flash heads. I'm guessing 100-150w.. Does anyone know?

I would put the SB-800 at 75 watt seconds.

For one thing, it measures very close to one stop down from a 160 watt second Alienbees, when both are individually in the same umbrella in same situation.

For another, energy in joules (same as watt seconds) is computed as 1/2 CV².

SB-800 C is 1400 uf, and V is 325 volts, which computes 74 watt seconds.
(tolerances are not tight on this).

Speedlights can be zoomed long, which makes them brighter in that concentrated circle. It is very much a "power per unit area" concept. GN and brightness depends as much or more on the reflector than on the power. Is it making a spot on the wall, or illuminating the entire wall?

And also very noticeable, speedlights recycle slower. We must wait on the slowest one.

Hugowolf Forum Pro • Posts: 12,674
Re: SB 800/ SB 900 power output in watts

WFulton wrote:

Kodak22 wrote:

Just wondering how they stack up against studio flash heads. I'm guessing 100-150w.. Does anyone know?

I would put the SB-800 at 75 watt seconds.

First let me thank you for stating the correct units. Watts make absolutely no sense for flash lighting. The units are watt seconds, abbreviated to Ws, not W/s, which would be watts per second. Joules, abbreviated to J, are the same thing, but the only manufactures that seem to use joules are Broncolor – a pity, since joules would probably be less confusing.

It is unfortunate that B&H, and many other retailers, are prone to erroneously using W/s.

For one thing, it measures very close to one stop down from a 160 watt second Alienbees, when both are individually in the same umbrella in same situation.

I have done the same thing with a 160 AB and Canon 550ex, which has about the same output as the Nikon SB-600, with similar results. I used identical soft boxes.

Strangely, when I recently had a 550ex and a Profoto D1 500 Ws unit in identical soft boxes, I got nearer to 60 Ws. I don’t know whether the Profoto is more efficient than the AB or not, but I don’t have the AB anymore, so I can’t try again with all three.

To get an even coverage with the speed light, even zoomed out fully, I have to use a Stofen Omnibounce. This definitely cuts the output some. When measured without the diffuser, at the center, about a metre from the face of the soft box, the 550ex has about the same output as the AB, but the edges are clearly not as bright as the centre.

So my estimate would be in the 60-80 Ws range.

Brian A.

DecibelPhoto Contributing Member • Posts: 791
Re: SB 800/ SB 900 power output in watts

I've always heard 60 w/s

OP Kodak22 New Member • Posts: 13
Re: SB 800/ SB 900 power output in watts

Thanks all, and I shall use Ws in future! The reason for the question was to decide between portable studio flash (Lumedyne, Quadra) and SB flash units. Weight vs output and the extra weight seems worthwhile (400Ws or 2 x 200Ws) if these estimates are accurate.

Quantum Help Senior Member • Posts: 1,666
Re: SB 800/ SB 900 power output in watts
1

Kodak22:

The true measure of how much light is output by any flash is measured bu its guide number. Watt secionds is the amount of power applied to the flash circuitry and can be affected by the efficiency of the circuitry. In order to get a fair comparison, measure the Speedlights at a 50mm zoom setting and ISO 100. That was the standard years ago before zoom heads became commonplace in Speedlights. According to published guide number in their manuals here are the comparisons and resulting un-diffused output at 10 feet.

Nikon SB800 GN144 f/14
Nikon SB900 GN131 f/13
Quantum T5d-R GN 160 f/16 (almost double the Speedlights)
Quantum X5d-R 400 w/s GN 220 f/22 (almost 4 x the Speedlights)
Alien Bees B800 GN 320 f/32 (lmost 8x the Speedlights)
Alien Bees B1600 SN 450 f/45 (almost 16x the Speedlights)

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Hugowolf Forum Pro • Posts: 12,674
Re: SB 800/ SB 900 power output in watts

Quantum Help wrote:

Kodak22:

The true measure of how much light is output by any flash is measured bu its guide number. Watt secionds is the amount of power applied to the flash circuitry and can be affected by the efficiency of the circuitry. In order to get a fair comparison, measure the Speedlights at a 50mm zoom setting and ISO 100.

You cannot get a fair comparison that way, there is no way to zoom a studio flash and comparable reflectors don’t work either, because you are assuming an even light spread.

That was the standard years ago before zoom heads became commonplace in Speedlights. According to published guide number in their manuals here are the comparisons and resulting un-diffused output at 10 feet.

Nikon SB800 GN144 f/14
Nikon SB900 GN131 f/13
Quantum T5d-R GN 160 f/16 (almost double the Speedlights)
Quantum X5d-R 400 w/s GN 220 f/22 (almost 4 x the Speedlights)
Alien Bees B800 GN 320 f/32 (lmost 8x the Speedlights)
Alien Bees B1600 SN 450 f/45 (almost 16x the Speedlights)

They might be undiffused, but they are certainly not unbiased. f/16 is not, by any measure, almost double f/14. And who is to believe Paul Buff’s inflated Alien Bee figures.

Brian A

michaeladawson Forum Pro • Posts: 12,894
Alien Bees are inflated?

This is the first I've read a comment that Alien Bees numbers are inflated. Are you saying that the 320 and 640 Ws specs of the AB units do do not stack up against others manufacturers? Is this true of all the PCB models (AB, White Lighning, Einstein) or just the AB?

I ask because I've been considering the purchase of some monolights,

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Hugowolf Forum Pro • Posts: 12,674
Re: Alien Bees are inflated?

michaeladawson wrote:

This is the first I've read a comment that Alien Bees numbers are inflated. Are you saying that the 320 and 640 Ws specs of the AB units do do not stack up against others manufacturers? Is this true of all the PCB models (AB, White Lighning, Einstein) or just the AB?

I haven’t used ABs for a few years, so I have no way of measuring their efficiency against other systems. But I’m sure that their ‘actual’ watt second ratings are no better or worse than anyone else. For years Paul Buff claimed that ABs were more effective than other lights, and had this ridiculous ‘effective’ watt second labeling.

This still exists today on the website and in the naming. The AB400 is 160 Ws, not 400 Ws. Watt seconds are not a measure of light output, so the output is one brand of n watt seconds may differ a little from another of n watt seconds, but nothing like the difference between 160 and 400 Ws (more than a stop).

I ask because I've been considering the purchase of some monolights,

There are no perfect lighting systems out there, no matter how much you are willing to pay. As lights, ABs work well: they are ugly, the back panel controls are poorly designed (if they were actually designed), they lack any handle or grip, etc – but they are cheap (as in relatively inexpensive).

The Einsteins (unfortunate naming), on the other hand, while suffering the same cosmetic deformities, are quite innovative, especially when coupled with the ‘CyberCommander’. Aside from the casing, back controls, and handle, the only things lacking are an app to run them from a computer and something with a higher output (640 Ws being borderline for outside use). But given the price, two Alberts are going to be cheaper than most 1000-1200 Ws units.

Brian A

OP Kodak22 New Member • Posts: 13
Re: Alien Bees are inflated?

Any idea how the Lumedynes stack up against the other systems you mentioned?

WFulton Senior Member • Posts: 2,698
Re: SB 800/ SB 900 power output in watts

Quantum Help wrote:

The true measure of how much light is output by any flash is measured bu its guide number.

Oops! No, is way too superficial by far. Guide Number is merely related to the exposure to use at the many very carefully defined situations.

Speedlights have many guide numbers, one for every possible zoom setting - and for every power level too... which is a BIG chart in the flash manual. Also for every ISO too of course, we have to compute that.

If you zoom short and wide, all the power is dispersed over a wide area, more dimly. If you zoom in long and tight, all the power is concentrated into a smaller spot, which is certainly brighter. The flash "power" is the same, but there could easily be a 4x difference in brightness. Illumination is about "power per unit area that is covered". GN is about ONE carefully defined situation of coverage area.

So the Guide number is as much or more about the reflector choice than about the power level. GN can ONLY be compared when all lights are doing the same job of covering the SAME area size.

GN is generally useless for studio lights, because too many possible lighting modifiers are used (softboxes, umbrellas, grids, snoots, etc), so they normally specify watt seconds of input electrical energy. Buy a light meter.

Hugowolf Forum Pro • Posts: 12,674
Re: Alien Bees are inflated?

Kodak22 wrote:

Any idea how the Lumedynes stack up against the other systems you mentioned?

Sorry, I have never used them, so I have no idea.

Brian A

UKphotographers Veteran Member • Posts: 4,333
Re: Alien Bees are inflated?

Kodak22 wrote:

Any idea how the Lumedynes stack up against the other systems you mentioned?

They're portable, durable and powerful and provide great light. Older packs are limited to the lowest 50ws output, although you can split that between two heads. Newer packs go down to around 3 - 6ws. They're basic, but this is quite an attractive feature.

http://lumedyne.com/products.asp

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Joseph S Wisniewski Forum Pro • Posts: 34,141
Almost double, except it's not...

Quantum Help wrote:

Kodak22:

The true measure of how much light is output by any flash is measured bu its guide number. Watt secionds is the amount of power applied to the flash circuitry and can be affected by the efficiency of the circuitry. In order to get a fair comparison, measure the Speedlights at a 50mm zoom setting and ISO 100. That was the standard years ago before zoom heads became commonplace in Speedlights. According to published guide number in their manuals here are the comparisons and resulting un-diffused output at 10 feet.

Nikon SB800 GN144 f/14
Nikon SB900 GN131 f/13
Quantum T5d-R GN 160 f/16 (almost double the Speedlights)

Sorry, but that's not true.

(160/144)^2 = 1.23, 23% more is very far from "almost double".
(160/131)^2 = 1.49, 49% more is again, nowhere near "almost double".

Those are the kind of statements that get you in trouble with Advertising Standards and similar agencies in other countries.

Quantum X5d-R 400 w/s GN 220 f/22 (almost 4 x the Speedlights)

2.33x and 2.82x, not "almost 4x"

Alien Bees B800 GN 320 f/32 (lmost 8x the Speedlights)

4.93x and 5.97x

Alien Bees B1600 SN 450 f/45 (almost 16x the Speedlights)

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Joseph S Wisniewski Forum Pro • Posts: 34,141
Statistically insignificant Lumedyne report...

Kodak22 wrote:

Any idea how the Lumedynes stack up against the other systems you mentioned?

Disclaimer. This is not a statistically significant observation. It is my observation, and I have never heard of another photographer having an experience like this.

A Lumedyne once gave me one of the worst electrical shocks in my life, a "throw you across the room" kind of shock. This was during normal, responsible use, not some attempt to repair or modify the unit.

I am not inclined to give them a second chance at me.

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Armenian genocide survivor, amazing cook, scrabble master, and loving grandmother. You will be missed.

Ciao! Joseph

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Joseph S Wisniewski Forum Pro • Posts: 34,141
Not that I've ever seen...
1

michaeladawson wrote:

This is the first I've read a comment that Alien Bees numbers are inflated.

You'll read a lot of things concerning Paul C. Buff products that aren't true.

Are you saying that the 320 and 640 Ws specs of the AB units do do not stack up against others manufacturers? Is this true of all the PCB models (AB, White Lighning, Einstein) or just the AB?

I ask because I've been considering the purchase of some monolights,

They "stack up" perfectly well.

Some people mention the "equivalent watt seconds" numbers that Paul Buff used to use. Oddly enough, I found those were pretty useful. Back in the early Paul Buff days, I found that the 1200 "equivalent W-S" Ultra 1200 matched fairly well with a real Speedotron 1200 W-S. That's more about the inefficiency of pack-head systems compared to monolights. Any useful cable, say 18 feet on a Speedotron, cuts power by about half. That's also why Speedotron users tend to accumulate extra cables, so they can plug more cable extensions into a light to lower its power.

But I've run mixed studio settings with the Ultra 1200s, which are specced at 600 actual W-S, with 600 W-S Elinchroms, and they match right up.

Same thing with the Bees, the 800 matches the Elinchrom Style 300, the 1600 does fine against the Elinchrom Style 600.

Same thing mixing Paul Buff with Photogenic Solair, Broncolor, Speedotron, and Novatron.

It's kind of odd, that people complain about the Buff "equivalent W-S" numbers, because I've got 20+ year old Paul Buff lights that had every possible number in their manuals:

  • equivalent W-S

  • actual W-S

  • light output in Lumen-seconds (taken with a spherical integrating photometer)

  • guide numbers with several different reflectors.

I can't think of anyone else who's as honest in their advertising.

You'll run into "Buff haters" all over the place. One claim you see repeated, over and over, is that Alien Bees have more color variation than other brands of lights. That's true, but meaningless.

All conventional "variable voltage" monolights (which is, essentially, every monolight on the market except Paul Buff "Einstein" and Photogenic "Solair") share one characteristic. The color temperature drops about 80K for every stop you reduce power. With the Cyber Commander control, Alien Bees and White Lightnings let you reduce power 5.3 stops, from full power to 1/75 power, so they drop about 425K. I can't name another variable voltage monolight with that large a control range.

The Elinchrom BX and RX (I've used a lot of Elinchroms, and the loudest Buff hater has Elinchroms) let you reduce power 4 stops, from full power to 1/16 power. So, they only drop 320K. Big whoop. If you limit the Paul Buff lights to the smaller control range of the Elinchroms, they perform the same way.

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Richard Grant New Member • Posts: 2
Re: Not that I've ever seen...

We are using SB-800's and SB-900's to shoot artworks at a museum. We have been doing this for years with no issues, but now a lender to an exhibition we are shooting is raising a question about excessive light exposure from the flashes. We have always been told that the short duration of the flash limits the exposure to quite low levels. In a post above someone estimates the output of an SB-800 at 75 watt-seconds. Since the duration at full power is 1/880 of a second (according to the specs in the manual), that would make the total output of one SB-800 flash at about .085 of a watt. Is that right? Also, how does one factor in the distance from the object combined with the area of the object, assuming the flash zoom is set to the widest angle? It would seem that even with 8 flash units there is very little total light exposure.

Richard Grant New Member • Posts: 2
Re:calculation mistake in calculation of output from SB-800

OK. I made a dumb error in my assumptions for the calculation I tried above. The 75 watt-seconds already includes the factor of the duration of the flash. Therefore I now think is should be:

75W/S * 8 flash units = 600W/S. This assumes the object is receiving all of the light. Since we put the units back quite a way for the sake of evenness, the object receives only a portion of the 600 W/S. To be very conservative, let's say half of the light. That would mean 300 W/S. This would be the equivalent of a 60 watt bulb for 5 seconds.

Did I get it right this time?

CraigBennett
CraigBennett Contributing Member • Posts: 699
Re: Not that I've ever seen...

Richard Grant wrote:

Since the duration at full power is 1/880 of a second (according to the specs in the manual), that would make the total output of one SB-800 flash at about .085 of a watt. Is that right?

No, it is rated at 76WS of energy at t.5, so you are getting 1/2 of the 76W for that 1/880 second. Total amount over 1/440 second (considering full power dump).  Unless Speedlights are rated at T.1 than 90% will be dumped in 1/880 second.

It is a mute point for your scenario, because Joules (WS) is the energy dumped into the flash tube, it is not a true measurement of what your object being photographed will see.

Also, how does one factor in the distance from the object combined with the area of the object, assuming the flash zoom is set to the widest angle? It would seem that even with 8 flash units there is very little total light exposure.

Yes, little light exposure, but very a very intense one.  That is what they are concerned about.

Inverse-square law  describes the light fall-off of any light source.

Regards,

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