Does the Profoto B2 Have Enough Power at 250Ws?

Does the Profoto B2 Have Enough Power at 250Ws?

Recently announced at the head of WPPI a couple weeks ago, was the Profoto B2 strobe system. The unit, small in comparison of its competitors, was arguably the most exciting product announcement this year at the popular photography convention. However, the burning question everyone has been asking is… is 250Ws enough for on location work like Profoto suggests?

Admittedly, I was one of the biggest skeptics. If you’re at all familiar with my work, you know that I have a habit of using intricate lighting arrangements on location, paired with ND filters to stop down the ambient light, allowing me to shoot at f/1.2-f/3.5 for the majority of my work. Because of this, I am typically overpowering the sun, firing at full power to achieve the lighting I need to overpower both the 4-8 stops of ND on my lens and harsh desert sun while maintaining a shallow depth of field. So when I’m maxing out my Profoto B1s at 500Ws, I have to assume that the Profoto B2’s 250Ws is not nearly enough, right? Wrong.

Light works slightly different than what one might think. You’d assume that 500Ws would give you twice the power that 250Ws would give you, giving you a massive advantage in power and versatility, but it doesn’t work quite like that. Sure - it’s double the power, but that equivalents to about 1 additional stop of light in total. You see, one stop of light refers to either doubling the light, or cutting the light output in half. So with that said, the Profoto B2s are only one stop short of what the Profoto B1s and other popular strobes are. So when shooting at 1/200th of a second at f/2 at 500Ws, the same can be achieved using 1/200th of a second at f/1.4 at 250Ws coming from your strobe. Here, let’s get a visual out of the way to hammer this idea home.

As the picture above illustrates, even on a clear sunny day in New Mexico, the B2s are more than enough power to overpower the sun. Each photo was taken at the same time, using the same modifiers. One was with a Profoto B2 at full power (250Ws) while the other one was with a Profoto B1 at full power (500Ws). By simply stopping down the aperture a full stop, we were able to get very similar results. This is because for each doubling of power in Watt seconds, you'll gain only one stop of additional light. Additional examples of the Profoto B2 overpowering the sun can be found below --

High Speed Sync Functionality

Another function to address with the new Profoto B2s is the High Speed Sync (HSS) functionality built into the unit. This allows you to shoot at sync speeds faster than 1/200th of a second, by firing multiple strobe flashes during the duration of the shutter opening and closing. This allows you to stop down on ambient light, without effecting the off camera flash (with the exception of power limitations). While firing at 1/8000th of a second means you'll be losing power from your strobe as well (it can only fire so many times at full power firing 1/8000th of a second), I've found that it works well at maintaining consistent lighting power, while still overpowering the sun. While using HSS sync will cut the power consumption down on the strobes, it cuts down the power at a much slower rate than an ND filter would at full stops. 

So with that said, the Profoto B2s are more than enough power to use for outdoor uses. Evidence of this also comes in the fact that the Canon 600EX-RT is around 70Ws, and is considered one of the most powerful speedlights available for photographers. That puts the Profoto B2 at about 3.5 times more powerful than a standard high end speedlight. At first, I was a huge skeptic on whether or not 250Ws would be enough for my needs on location. After using the B2s on bright, cloudless days with ease, I'm more than confident that 250Ws is enough power for the average photographer.


If you'd like to know more about lighting and test out the Profoto B2 (and B1) strobes for yourself, I am hosting a series of two day workshops all over the United States in the coming months. These workshops are 2 day workshops where day one focuses on lighting using off camera flashes in an outdoor environment, and day 2 focusing entirely on marketing your business and high end retouching. With over 15 hours of education, the seating of these workshops are extremely limited, and can be reserved on my workshop website. The first set of workshops are set to take place in Miami, FL, Phoenix, AZ, and Denver, CO.

Zach Sutton's picture

Zach Sutton is an award-winning and internationally published commercial and headshot photographer based out of Los Angeles, CA. His work highlights environmental portraiture, blending landscapes and scenes with portrait photography. Zach writes for various publications on the topic of photography and retouching.

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The B2's are powerful enough if your flash is within 2-3 feet of the subject. Try to get a landscape, waist up portrait at a more reasonable 5-8 feet from softbox to subject and you would likely be pushing past the limits of 250Ws on a bright sunny day.

The inverse square law would suggest that it could be done. Remember, light falloff is inversely proportional to the square of the distance of the light. So every time you double the distance your light is from your subject, you're only losing (1/2)^2 or 1/4th of the power (roughly).

An object that is twice as far away from the energy source as another object receives one quarter of the energy.

Great article though. Thanks for all your time and effort to make posts!

Sorry Zach, that is not right.

You are losing 2 stops, i.e. double the distance, ¼ the power. Not ¼ less, that would only be a half stop loss, if only, but alas it is not.

Yup, you're right. I wrote my response in haste...and misspoke as a result. That said I still believe the B2s are enough power for waist up portraiture and landscapes. 250Ws still packs a lot of punch, and backplates are ofcourse an option in a pinch

Zach you were correct to quote the inverse square just messed up the fractions. LOL

Hi Zack, do you still feel confident about B2's power now that you are aware of that every time you double the distance you will only have 1/4 of B2's power? It's really not promising. Even with the B1 it can barely overpower the strong sun in the event of shooting a full body portrait with softboxes.

I add a 3stop ND filter. Allows me to use more flash power.

ND filter will allow you to sync your flash in bright daylight but it reduces the power of flash as well.

How is that? If I can avoid using HSS (where power is reduced) and stay at, say 1/200s?

With 3stop ND you are only at 1/8 power. What good is that for?

If I need f2 and 1/1600s, I could use 1/200s with 3 stop ND and use the flash to lighten up the model. The web is full of examples that this works nicely.

ND cuts global exposure which includes your flash power as well (even your flash output can reach maximum). The reason you see it working is because camera is using F2 which absorbs a lot of light. Same applies to HSS as well. Weak flash output and large aperture counter-balance each other.

Yes. But HSS costs you in addition to reducing exposure by increasing shutter speed. Demonstrated nicely by on his Tangents blog. He measures around 2 stops additional loss in power when switching to HSS with SB910 speed lights, for example. So an ND filter allows for more power if you stay at maximum sync, with the hazzle ofmounting them, focusing etc. Using a B1 or INDRA500 with enough power to start with, I don't basically care anymore.

Thank you for this article. I agree that 250Ws would be enough for most of my use shooting portraits, but the real question is why should I consider the B2 if I can get the new Elinchrome ELB 400 which has more power and is less expensive! And I don't care about TTL, never used it!
Can anyone give us a good comparison between those portable systems as I am really considering getting one of them?

I'm with you. TTL is a consumer commodity. Can you really trust your meter, interpreting every reflection and ambiguously varying exposure based on random fluctuations it reads from shot to shot? I'm all manual, all day. Unleas you're a shoot-n-burn wedding photographer, TTL is useless to me. High speed sync though, now that I could get used to :-)

You are right that a pro wouldn't rely on TTL when on a shoot. However the Profoto TTL system really works magic in outdoor shooting. It works as a preliminary test flash to give you feedback on your power setting, you then can make a judgement call whether the TTL flash gave enough output and switch("lock on" ) to manual flash mode and make adjustments accordingly.

Well TTL is great for speedlights during receptions.

Yeah for my portraits I shoot in manual mode. No need for TTL.

The thing I question the most about the B2's is the price point. For (1) B2/battery pack vs. (1) B1 the price point is basically the same. But with the B1 I still get my high speed sync plus the extra 1 stop of light. As far as portability goes, well, that can be debated all day long and I think it boils down to personal preference. I have not used the B2's but I have used a Ranger Quadra for the past few years and I have to say that I prefer the overall portability of the B1 with no external battery pack over my Quadra. That isn't even taking into consideration the extra stop of light that does matter, and matters even more when we start getting into HSS. So for me I just don't really get the B2's. Just my opinion though. I know a lot of people have been raving about them and in all honesty, I don't think you can go wrong with either the B1 or B2 as they are both amazing light shaping tools. I would take either of them over my Quadra due solely to the abilities that come in to play with the HSS.

If the price point for the B2's had been say, 60-70% of the B1's, I think Profoto would have had a really amazing portable system with the combination of the B1 and the B2. You could have had an extremely versatile 3 light setup for around $4k in that scenario. But here's to dreaming haha.

I totally agree with you on the price point. When I initially heard about the 250ws output I was expecting a more economical portable flash solution. Never did I expect the B2 would priced above B1. Especially when you get the location kit with two heads you are not gaining any power at all. I also had an port unity to play around the OCF line of modifiers a bit, they are quiet plastic in handling. I would much prefer speedlights for portability and B1 or above if I needed the power. B2 fills no need so far except perhaps for folks who want a quick mobile studio setup with 3-4 lights.

It may be true that speed lights are not cheap, they serve a very different purpose when used on camera as fills. B2 is very clumsy to be used as OCF. Yes they do offer more power and fast recycling but one will need to install a bracket, carry the battery pack and mount the trigger and the flash head on. Don't forget to tighten up the 2m long cable! That's a lot of weight! I don't see a situation when people cannot be satisfied with a top of the line speed light on camera.

When used as OCF it's a different story. B2 then have an edge over regular speed light in terms of power and easy to fit light modifiers. However it has obvious limitations. B1 will serve better. For first time OCF buyers getting the B1 will not only allow ultimate portability but it also means you get twice the power or twice the charge per battery, it will allow the photographer room to grow from just a run and gun wedding photographer to being able to a true master of light when situation a cheaper price.

I walked into B&H yesterday to check these out. $2k for single 250 w//sec light with cords? Sorry, not a
on-location solution. Zach, your examples are good, but they're close-up shots. How about a full body environmental portrait? 250 w/sec in full sunlight through a softbox won't do. Plain and simple. I ended up getting another B1 yesterday, to supplement the two B1s I already own. Slap on an umbrella, or a softbox, mount it on a stand, and move it anywhere, anytime. No external battery packs nor cords to pack up. All of that for the same price. I was really crossing my fingers for a 1000 w/sec B1s, bit I'll manage :-)

The example photos show that it's able to shoot other than just headshots. I have full confidence that I can use these on location and get full body environmental portraits without any issues.

I got to work with another photographer using these this weekend. While I think they are great, they are definitely far from perfect. HSS is an incredibly useful feature, but remember you can Hypersync when pairing the right triggers with an Elinchrom Quadra system. This gets you that sun cutting shutter speeds but allows you to still fire the strobes at a high power where as the HSS in the Profoto cuts strobe power. Ultimately I think Elinchrom has the advantage here. Really the biggest advantage I see over Elinchrom is the modifier mount.

As for comparing to the B1, I find the B1 to be significantly more convenient in the field. More power, and completely self contained. IMO, the only advantage the B2 has is the small heads can quite effectively be mounted anywhere with a Gorilla Pod where the B1 would be too heavy.

At the price, I think both the Quadras and the B1 are better location options. The B2 either needs more useful power or a huge price cut for me to consider them.

Why would the majority of people choose the B2 over the Profoto AcuteB2 600 for half the price?

B2 is significantly lighter than the Acute's. B2 also has TTL, and HSS, and can use the new light weight OCF system (due to the low heat LED lighting)

Not exactly apples to apples. Acute B2 is larger, more cumbersome, and far from ideal power controls. B2 is much smaller and lighter, more protected flash tube, more modern controls, and does offer TTL and HSS. Acute is great if you are locked down on location and very methodically and precisely creating images. B2 is better suited for on the go, run and gun style shooting.

what modifier are you using on those high speed sync shots. Quality of light looks nice!

5ft Profoto Octabox. I think Clay Cook was using something similar in the photo he provided for the article.

Zach - I'm contemplating a B2 system (shooting typically 1 person or 2-3 people in studios or home/office, along with late aft portraits, some group shots w 5-12 people and every once in a while shooting in the open daylight with couples on a beach or in a field, etc.). I see everyone's comments and I am fretting. From the last pic you posted, it looks like the model was actually shot in the shade of the umbrella. The twigs in the first original pic or two are darkened. So is that correct? I'm trying to figure out how to not spend a small fortune and I really like the concept of the B2 particularly because I candidly "need" TTL fpr Sony as I'm a one-man band and need to move quickly. I've never used a off-camera system so am thinking TTL is in my best interest until I advance knowledge. Thanks for any comments.

I do not bash on tech, usually I just do not comment but I want to Ask you consider this:

This pack is a 2 light pack with asymmetric power distribution like Elinchrom quadra and such.
Chanel A gets about 66% - Chanel B gets 34% so 250Ws is the achieved by using only one head, as soon as you add a second head it would be more like 165Ws - 85Ws that is like 2xCanon speedlights (Ch A) - 1x Canon speed light (Ch B).

So do they have enough power? I hear some photographers having dificulty with the Ranger Quadra which is a 400Ws asymmetric pack 264Ws (Ch A) -136 (Ch B). For some people it might, but it would be very limiting I can imagine. Better off with 2x B1s or better yet a 500-600Ws+ studio monoblock and a Li-Ion pack with wall outlet plugs.

250Ws of TTL light on a stick is useful if you have a VAL to direct and you need to get something done quick, but as you say, once you start putting two heads on it I don't see why I wouldn't stick 2-3 cheaper speedlites on one stand and 1-2 on another or look at better value, more capable lights. Look at Phottix Mitros+ which can also be mixed with Indra 360/500, all with same trigger and TTL if that's your thing. Otherwise Elinchrom ELB's have more power per dollar and per pound as well as action head option for freezing motion. I don't know that the B2s fill a gap between speedlights and say B1s or Indra 360/500s at that particular price. For anything other than a single head being used as a TTL light on a stick I'm not sure I see the advantage of the B2.

I think the main audience for B2's are wedding/event photographers, that need a little more power than a speed light that also would like the modifiers that Profoto provides.

Yes absolutely that's the market and it will suit some perfectly. Especially as I say as a TTl light on a stick with an assistant. No one wants to stick a full B1 over someone's head! But personally there's no way I'd consider sticking that on top of my camera all day with the pack over my shoulder instead of a Canon 600EX RT and then popping it on a stand for formals and dances. Form-factor/price not working for me. And if I'm popping things on stands I think I'd rather more power with Elinchrom or Mitros+ on camera and a Indra 360/500 on stands as they work together nicely off same system from what I understand. I'd be interested to see it in action but not quite there, especially at the price. Someone is going to nail this niche properly some day.

Also if you're mixing these with B1s it seems a shame it doesn't share a battery.

Zach, great article but I have to ask - are you still going to using Variable ND filters? ( I just re-read your ND filter article last night)

Are they that tough to focus in bright conditions and/or if you place your subject in the shade of the softbox you may be using? Were you able to shoot effectively in bright conditions without having to resort to HSS strategies?

I'm still using ND filters, and will always have them in my bag...that said, I am hoping to be able to fizzle them out at some point by using HSS. We'll have to see how that works out though.

That has always been my issues with ND filters. Sometimes I have to manual focus if I have them stopped for 7-9 stops.

You really go 7-9 stops and try to focus that way? Wow....that must be for the brightest cloudless mid-day conditions though, correct?

B1 to B2 Size comparison. B2 is infinitely more portable for those that need to travel without worrying about checking a bag. The Kit could fit in a camera bag with your other gear.

Think I would rather have the phottix indra for half the price...

I'd rather have the NiceFoto nflash Q for one quarter of the price.

I believe 400ws is the baseline for outdoor flashes. Even a 430ex works during on-camera daylight. As a production photographer, I love using my 60inch octa. My Hensel Porty is often on half power(600ws) during a sunny day photoshoot.

Thanks for these very useful shooting samples and the behind the scenes shot. I was close to getting a b2 kit but its clear to me I'll need b1s first so I have power in reserve for full length environmental shots and the ability to knock the ambient light down a couple of stops for more dramatic shots. I would find the b2's very useful for supplemental lighting or in other specific circumstances and will probably pick one or two up at a later point.

My local dealer has given me a Profoto B2 kit to test .My main interest was to compare this new Profoto unit with the speedlites canon 600 rt in terms of output power . Both two units without modifiers. Same distance. Full power. Canon 600 rt with internal batteries and zoom set at 35. Just one B2 unit plugged in his external battery. Measurement by lightmeter .Test. The output power is exactly THE SAME .This is what you get. With the speedlite zoom set above 35 mm, it gives more output power than the B2 .Try by yourself.
The same test with Profoto B1. You need two canon 600 rt to equal the ouput power.

This test however has problems on its own. B1/2 D1 when used bareheaded has a super wide light spread at 77 degrees to account for filling the light inside large softboxes. Once you add a standard zoom reflector on it to focus the light forward you will see the massive difference. : )

Yes, Im agree. When you add a standard zoom reflector on B1/2 D1 to focus the light the ligth is focused. When you increase the zoom of the speedlite or add a reflector on a speedlite to focus the light the ligth is focused. As well.

Sorry Sorry Sorry.. This article is misleading and total profoto marketing gimmick.. if you want to prove a point don't prove it with just one headshot which is not even a good photo. if you want to show B2 over powering the sun please take it out in harsh sun light and dial down the aperture to highest, have the sun behind the subject and shoot B2 at full power for various distances. lets see the sun star burst along with the subject in good light.. why are you assuming everyone will want to shoot at f2 or f1.2 ? I want to shoot f16 or even more.. I am really disappointed with profoto for their false B2 marketing. well I would like to see good convincing videos which really show the power.. b2 is expensive and now u have to spend additional on a low aperture lens ? I am yet to see one good b2 video which really is honest.. if you are really honest you will do a reliable test and give a right feedback about b2 and not lies.. cmon show the sun in your pictures .. this is how I test any new light.. take the subject in harsh sun keep shooting at different apertures and always keep sun behind the subject.. create a shilhoutte and then fire the flash at different power till I don't see the subject with good light.. hope you can show that with b2

They look like great lights for close in use.