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speedlights vs. monolights- trying to make apples to oranges comparison

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mathew crow

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I've been shooting with all speedlights as off camera flashes, mainly Vivitar 285hv units. I've been wanting to buy one brighter/more powerful flash unit and I was looking at the Alien Bees and Adorama Flashpoint units. My question is how to the lowest power units ie, the AB400 and Flashpoint 320 compare in power to a speedlight like the Vivitar 285hv? I've only seen guide numbers for the speedlights and watt/seconds for the monolights so I can't tell how they compare. Do I need to go a step up to the AB800 or Flashpoint 620 to gain a significant boost over the speedlights?
Thanks!

--
My Pentax Photo Gallery Artist Page:
http://www.pentaxphotogallery.com/mathewcrow

My toys:
Pentax K20D
DA* 16-50/2.8 ED AL IF SDM
DA* 50-135/2.8 ED IF SDM
DA 55-300/4.0-5.8 ED
DA 18-250/3.5-6.3 ED IF AL
FA 77/1.8 Limited

AF 540FGZ Flash
 
Look far enough in the AB web site, and you'll find typical f stops at various distances with various AB units, with various reflectors.

On a Vivitar 285, you have a guide number around 110 at ISO 100.

That includes the Vivitar's built in reflector.

In the world of studio lights, for the most part (Dyanlite being an exception) there's no built-in reflector to use as the basis of determining a guide number, so there are different numbers for the flash, based on different reflectors.

That said, an AB400 with a plain reflector is around the same power as a Vivitar 285, except the AB recycles a lot faster.

BAK
 
BAK

Thank you for the explanation, I have one question based on your response.

If one Vivitar will put out the same power as the AB400, then would it be realistic to use 2 or 3 Vivitars firing simultaneously at 1/2 power to achieve the same power as the AB400 and achieve equal recycling times?

The reason I ask is that I would prefer the Vivitar's for portability and for multiple light set up when one does not need that much power
BAK said:
Look far enough in the AB web site, and you'll find typical f stops
at various distances with various AB units, with various reflectors.

On a Vivitar 285, you have a guide number around 110 at ISO 100.

That includes the Vivitar's built in reflector.

In the world of studio lights, for the most part (Dyanlite being an
exception) there's no built-in reflector to use as the basis of
determining a guide number, so there are different numbers for the
flash, based on different reflectors.

That said, an AB400 with a plain reflector is around the same power
as a Vivitar 285, except the AB recycles a lot faster.

BAK
Click to expand...
 
Not going to answer your specific question, but the benefit of using a strobe is more than just about power. It is also about accessories such as soft boxes, barndoors, beauty dishes, etc. Also you can "see the light" with the modeling lights before you take a picture. There are pros and cons to everything, just have to think about all the options for use in the future.

Just my thoughts.

John
--

Feel free to use any of these additional letters to correct the spelling of words found in the above post: a-e-t-n-d-i-o-s-m-l-u-y-h-c If you find any extra letters, please place them here for future use...
 
I have the Flashpoint 620's and 18xx's;
and my associate has the AB 800 and 1600's

They are great for studio work, however, not so fun to take "on location"
(I often take a Novatron 3 head funpack / hardshell case for on-location events)

You can gang together 2 or more battery units (I have vivitar 283's, 285's, and Sigma Super DG 500's). I've strapped/velcro'd/duct-taped two or more battery flashes together to fire into (or thru) large umbrellas for "on location" lighting for formals at weddings or senior shoots. Very transportable and less hassle than strobes and extension cords or power packs.
 
It's hard to translate guide number into Ws, mostly because monolights have a much wider beam that doesn't go very far, whereas speedlights have a more concentrated beam.

The Ws affects mainly the fstop that you can use. With a speedlight, you'll get about F5.6 max (assuming ISO100). With AB400, you'll get F8 max.

Some people estimated about 80Ws for a typical flash (like Vivitar 285HV). In my experience, it's about right. I've used my Sunpak 383 together with an AlienBees B800 rated at 320Ws, and found that the Sunpak has about a quarter of the power. That means the AB800 has 2 more stops.

Pros for speedlight: small, portable, no power chords. I find it more useful, since I often shoot on location. The light weight is also great if you want to mount on a boom for hairlight, because monolights are usually too heavy for most, but the sturdiest lightstand+boom.

Pros for monolights: more power, quicker recycle (especially if you don't use full power at each pop), modeling light (which is good for visually seeing the light on the model and also good for autofocus), lots of accessories will fit it.
 
VRII said:
If one Vivitar will put out the same power as the AB400, then would
it be realistic to use 2 or 3 Vivitars firing simultaneously at 1/2
power to achieve the same power as the AB400 and achieve equal
recycling times?
Click to expand...
The Vivitar 285 does NOT put out the same power as the Alienbees B400, not even close. That assumption possibly might have been founded on guide number, but guide number depends on the coverage area of the flash - power per unit area so to speak. If we concentrate the power into a narrow beam, the light and guide number gets stronger within that narrow beam, but the "power is unchanged", and of course, the area covered is less. If you spread out the power into a wide beam, the light and GN gets weaker. Umbrellas need a wide beam.

The Vivitar speedlight has four guide numbers, depending on area coverage.
From the last two pages of the Vivitar manual online at Amazon, for ISO 100:

28mm zoom: GN 70 70x53 degrees coverage
35mm zoom: GN 100 60x40 degrees
50mm zoom: GN 120 465x34 degrees
105mm zoom: GN 140 27x20 degrees

From http://www.alienbees.com/specs.html , at ISO 100 the Alienbees B400 is:
GN 118 - 80 degrees coverage in standard 7 inch reflector.
GN 220 - 50 degrees coverage in optional 11 inch reflector.

In same situation (same coverage angle, same ISO, etc), then:
GN x 1.4 is double power (one stop) and GN x 2 is 4x power (two stops).

In an umbrella, you want about 80 degrees of coverage, to fill the umbrella. So then the Vivitar would be used at its widest zoom, 28mm, which is 70x53, which is more narrow than 80 degrees, and is also only GN 70 then. The umbrella reflection will reduce it more. Declaring 70x53 degrees to be approximately equal as 80 degrees circular coverage for this comparison greatly inflates the Vivitar ranking, it simply is not 80 degrees, and does not compare.

The Vivitar is not a real strong flash. For example, the Nikon SB-800 flash at 24mm zoom for the umbrella (78x60 degrees) has GN 98 there. And it actually and literally meters one full stop less than the B400 in same umbrella. One stop is half power. The Vivitar is less than half power. The SB-800 capacitor size and voltage literally computes to be exactly 75 watt seconds. The AB B400 is 160 watt seconds. 75 ws is about half the power of 160 ws, which agrees with metered measurements. The Vivitar has to be well less than half power.

Guide number has no meaning in comparisons unless the coverage area is also specified, and equal, but three Vivitars in an umbrella might compare to a B400.
The B400 will still recycle from full power in no more than 1/2 second.
 
WFulton

that was an excellent response! Allow me to ask the Next Question then, since the SB-800 is discontinued, would the power and angle of coverage of two SB-900's mounted together on a dual bracket fired at full power, equal the output of an AB400?

I understand recycling times will be about 3 sec for the SB-900's and teh cost would be doubled, maybe triple, but again I'm going for portability and the ability to control the light output directly from the camera.
WFulton said:
VRII said:
If one Vivitar will put out the same power as the AB400, then would
it be realistic to use 2 or 3 Vivitars firing simultaneously at 1/2
power to achieve the same power as the AB400 and achieve equal
recycling times?
Click to expand...
The Vivitar 285 does NOT put out the same power as the Alienbees
B400, not even close. That assumption possibly might have been
founded on guide number, but guide number depends on the coverage
area of the flash - power per unit area so to speak. If we
concentrate the power into a narrow beam, the light and guide number
gets stronger within that narrow beam, but the "power is unchanged",
and of course, the area covered is less. If you spread out the power
into a wide beam, the light and GN gets weaker. Umbrellas need a
wide beam.

The Vivitar speedlight has four guide numbers, depending on area
coverage.
From the last two pages of the Vivitar manual online at Amazon, for
ISO 100:

28mm zoom: GN 70 70x53 degrees coverage
35mm zoom: GN 100 60x40 degrees
50mm zoom: GN 120 465x34 degrees
105mm zoom: GN 140 27x20 degrees

From http://www.alienbees.com/specs.html , at ISO 100 the Alienbees
B400 is:
GN 118 - 80 degrees coverage in standard 7 inch reflector.
GN 220 - 50 degrees coverage in optional 11 inch reflector.

In same situation (same coverage angle, same ISO, etc), then:
GN x 1.4 is double power (one stop) and GN x 2 is 4x power (two stops).

In an umbrella, you want about 80 degrees of coverage, to fill the
umbrella. So then the Vivitar would be used at its widest zoom,
28mm, which is 70x53, which is more narrow than 80 degrees, and is
also only GN 70 then. The umbrella reflection will reduce it more.
Declaring 70x53 degrees to be approximately equal as 80 degrees
circular coverage for this comparison greatly inflates the Vivitar
ranking, it simply is not 80 degrees, and does not compare.

The Vivitar is not a real strong flash. For example, the Nikon
SB-800 flash at 24mm zoom for the umbrella (78x60 degrees) has GN 98
there. And it actually and literally meters one full stop less than
the B400 in same umbrella. One stop is half power. The Vivitar is
less than half power. The SB-800 capacitor size and voltage
literally computes to be exactly 75 watt seconds. The AB B400 is 160
watt seconds. 75 ws is about half the power of 160 ws, which agrees
with metered measurements. The Vivitar has to be well less than half
power.

Guide number has no meaning in comparisons unless the coverage area
is also specified, and equal, but three Vivitars in an umbrella
might compare to a B400.
The B400 will still recycle from full power in no more than 1/2 second.
Click to expand...
 
VRII said:
WFulton

that was an excellent response! Allow me to ask the Next Question
then, since the SB-800 is discontinued, would the power and angle of
coverage of two SB-900's mounted together on a dual bracket fired at
full power, equal the output of an AB400?
Click to expand...
Yes, the SB-900 is the same as the SB-800 in regard to power, and it recycles faster. Two should match the B400 power. 3 or 4 Vivitars should match it too.

But two SB-900 will cost $900. It offers many features your use may not need. Or one AB B400 cost $225. If you need battery operation, you could add the Alienbees Vagabond II battery system for $300, and still only reach $525 cost total (bulk and weight would be significantly different however).

I dont know your goals, but these measurements may be helpful, with same 45 inch white reflected umbrella, metered when distance is measured from the fabric. Manual full power level. ISO 200 (for ISO 100, open one stop.. For ISO 400, close one stop):

One SB-800 24mm zoom:
at 4 feet f/11 + 4/10
at 10 feet f/5.6 + 2/10

One B400:
at 4 feet f/16
at 10 feet f/8

It has been awhile, but I wrote that down once. I remember other times measuring the SB-800 to be one full stop different.

http://www.alienbees.com/specs.html also has an Output Measurements chart, read fine print under the chart for details.
 
Thanks to everybody for the great replies and advice. It seems the consensus is that the AB400 or Flashpoint 320 is still more powerful than the V285. I suppose I could get a battery back if I wanted to take the monolight on location.
--
My Pentax Photo Gallery Artist Page:
http://www.pentaxphotogallery.com/mathewcrow

My toys:
Pentax K20D
DA* 16-50/2.8 ED AL IF SDM
DA* 50-135/2.8 ED IF SDM
DA 55-300/4.0-5.8 ED
DA 18-250/3.5-6.3 ED IF AL
FA 77/1.8 Limited

AF 540FGZ Flash
 
Matherw, if you read through all that verbiage, you'll see the Vivitar and the AB400 are pretty much the same power with the Vivitar's head and the standard reflector on the Alien Bee.

BAK
 
Re> is still more powerful than the V285.

Doesn't matter.

What matters is what kind of light you want.

If you want light you can carry in a jkacket pocket, buy the Vivitar.

If you want flash that is automatic, buy the Vivitar.

If you want light that can be managed by reflectors, softboxes, umbrellas, softlighters, and modeling lights, and more, buy the Alien Bee.

And if you want to do serious work, buy the middle size Alien Bee, or some equally powered other brand.

It's possible to load sand into the back seat of an Impalla, but it's better to buy a truck.

BAK
 
BAK said:
Matherw, if you read through all that verbiage, you'll see the
Vivitar and the AB400 are pretty much the same power with the
Vivitar's head and the standard reflector on the Alien Bee.
Click to expand...
Pretty hard to understand that opinion. :) You must be fooled by Guide Number, trying to compare extremely unequal situations.

The AB B400 GN is 118 while covering 80 degrees with standard reflector.
The Vivitar 50mm setting GN is 120 while covering 46x34 degrees.

(source: http://www.alienbees.com/specs.html , and last two pages of Vivitar manual on Amazon: http://ec1.images-amazon.com/media/i3d/01/A/man-migrate/MANUAL000011531.pdf )

Both of these GN are near 120, so this situation would give about equal exposure, say f/12 at 10 feet. This must be your notion of being equal. However, the Vivitar is making only a narrow beam and a small lighted spot on the wall, while the B400 is illuminating the entire wall. That requires a huge power difference, not remotely equal.

For reference: With both at widest zoom (suitable for an umbrella), the Nikon SB-800 24mm has about 40% higher guide number than the Vivitar 285 28mm (GN 98/70 = 1.4). 1.404 is precisely 1 stop more, or double power.

Here is a picture of a SB-800 and the AB B400 (bare bulb, no reflector).



That round ring around the modeling lamp is the flash tube.

It is really hard to imagine these are equal lights, and if you meter them in the same umbrella, you easily see the B400 is one stop stronger, which is double (yet again - two doubles from the Vivitar - 4x power). Not remotely the same power.
 
mathew crow said:
I've been shooting with all speedlights as off camera flashes, mainly
Vivitar 285hv units. I've been wanting to buy one brighter/more
powerful flash unit and I was looking at the Alien Bees and Adorama
Flashpoint units. My question is how to the lowest power units ie,
the AB400 and Flashpoint 320 compare in power to a speedlight like
the Vivitar 285hv?
Click to expand...
the biggest difference you'll notice is that a larger source provides less fall off..... and a smoother more controllable source as well. your thought process is running like this right now: I know a Ferrari might be faster than a VW bug but if I have 3 VW bugs will they be just as fast.as a Ferrari?
 
That is a misleading analogy, the speed light is actually the ferrari, it's light, fast, portable, has a lower volume capacity of 2 passengers and more expensive than an AB400

Anyhow these analogies are just silly, the bottom line is trying to achieve the same light coverage as a mono light but with multiple speedlights, which offer portability and flexibility.
bm bradley said:
the biggest difference you'll notice is that a larger source provides
less fall off..... and a smoother more controllable source as well.
your thought process is running like this right now: I know a
Ferrari might be faster than a VW bug but if I have 3 VW bugs will
they be just as fast.as a Ferrari?
Click to expand...
 
If you want to stick with battery powered lighting, the sunpak 622 super is gn 200.

It's easy to use 6v Sealed lead-acid batteries and a 1.5 amp auto charger from walmart.

http://forums.dpreview.com/forums/read.asp?forum=1025&message=29542533

If you're interested, email for more detailed instructions.
VRII said:
Thank you for the explanation, I have one question based on your
response.

If one Vivitar will put out the same power as the AB400, then would
it be realistic to use 2 or 3 Vivitars firing simultaneously at 1/2
power to achieve the same power as the AB400 and achieve equal
recycling times?

The reason I ask is that I would prefer the Vivitar's for portability
and for multiple light set up when one does not need that much power
BAK said:
Look far enough in the AB web site, and you'll find typical f stops
at various distances with various AB units, with various reflectors.

On a Vivitar 285, you have a guide number around 110 at ISO 100.

That includes the Vivitar's built in reflector.

In the world of studio lights, for the most part (Dyanlite being an
exception) there's no built-in reflector to use as the basis of
determining a guide number, so there are different numbers for the
flash, based on different reflectors.

That said, an AB400 with a plain reflector is around the same power
as a Vivitar 285, except the AB recycles a lot faster.

BAK
Click to expand...
--
Click to expand...
 
bm bradley said:
mathew crow said:
I've been shooting with all speedlights as off camera flashes, mainly
Vivitar 285hv units. I've been wanting to buy one brighter/more
powerful flash unit and I was looking at the Alien Bees and Adorama
Flashpoint units. My question is how to the lowest power units ie,
the AB400 and Flashpoint 320 compare in power to a speedlight like
the Vivitar 285hv?
Click to expand...
the biggest difference you'll notice is that a larger source provides
less fall off..... and a smoother more controllable source as well.
your thought process is running like this right now: I know a
Ferrari might be faster than a VW bug but if I have 3 VW bugs will
they be just as fast.as a Ferrari?
Click to expand...
The analogy doesn't work.

Separate cars CAN'T "combine" to go faster.

But, three identical flashes at 1/3 power produce roughly the same output as one at full power.

Light is additive. Remember the 3-way light bulb?
 
Just to clarify, as the original poster, I wasn't the one who posed the question of combining multiple speedlights to get more power. That was somebody else. I was just wanting a more powerful flash to use as a main light and move towards using the speedlights for accents like rim and hairlights. And knowing that I could more easily add modifiers like softboxes and so forth with a monolight is attractive as well. Thanks still to everyone for the continued advice, posts, analagies, etc. I value everyone's feedback.
--
My Pentax Photo Gallery Artist Page:
http://www.pentaxphotogallery.com/mathewcrow

My toys:
Pentax K20D
DA* 16-50/2.8 ED AL IF SDM
DA* 50-135/2.8 ED IF SDM
DA 55-300/4.0-5.8 ED
DA 18-250/3.5-6.3 ED IF AL
FA 77/1.8 Limited

AF 540FGZ Flash
 
Robert J. Gonzalez said:
bm bradley said:
mathew crow said:
I've been shooting with all speedlights as off camera flashes, mainly
Vivitar 285hv units. I've been wanting to buy one brighter/more
powerful flash unit and I was looking at the Alien Bees and Adorama
Flashpoint units. My question is how to the lowest power units ie,
the AB400 and Flashpoint 320 compare in power to a speedlight like
the Vivitar 285hv?
Click to expand...
the biggest difference you'll notice is that a larger source provides
less fall off..... and a smoother more controllable source as well.
your thought process is running like this right now: I know a
Ferrari might be faster than a VW bug but if I have 3 VW bugs will
they be just as fast.as a Ferrari?
Click to expand...
The analogy doesn't work.

Separate cars CAN'T "combine" to go faster.

But, three identical flashes at 1/3 power produce roughly the same
output as one at full power.

Light is additive. Remember the 3-way light bulb?

--
Click to expand...
--

okay... you shoot with a few dozen speed lights, I'll shoot with my speedatron monolights. it'll be great fun :)
 
bm bradley said:
Robert J. Gonzalez said:
bm bradley said:
mathew crow said:
I've been shooting with all speedlights as off camera flashes, mainly
Vivitar 285hv units. I've been wanting to buy one brighter/more
powerful flash unit and I was looking at the Alien Bees and Adorama
Flashpoint units. My question is how to the lowest power units ie,
the AB400 and Flashpoint 320 compare in power to a speedlight like
the Vivitar 285hv?
Click to expand...
the biggest difference you'll notice is that a larger source provides
less fall off..... and a smoother more controllable source as well.
your thought process is running like this right now: I know a
Ferrari might be faster than a VW bug but if I have 3 VW bugs will
they be just as fast.as a Ferrari?
Click to expand...
The analogy doesn't work.

Separate cars CAN'T "combine" to go faster.

But, three identical flashes at 1/3 power produce roughly the same
output as one at full power.

Light is additive. Remember the 3-way light bulb?

--
Click to expand...
--
okay... you shoot with a few dozen speed lights, I'll shoot with my
speedatron monolights. it'll be great fun :)
Click to expand...
Has nothing to do with what I said , so what's your point?
 
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