Comparing power: Studio lights vs. speedlites / speed lights
Speedlights pack a huge amount of light for the size. Very portable, and loaded with sophisticated features, owning a speedlight is a must. A simple choice.
Studio lights and the larger portable flashes such as the Profoto B1 TTL flash (B&H / Amazon) , offer a lot more power than speedlights. Exactly how much more powerful, isn’t all that easy to gauge. There’s very little available as direct comparison. Even the specs aren’t directly comparable. Speedlights’ power is given as a Guide Number (GN), and studio lights’ power is usually given in Watt-second. Not an obvious translation between the two of them.
The Profoto B1 flash (affiliate) is quite powerful, offering 500Ws as a maximum. It also features TTL capability, and can be wirelessly controlled. All this gives the B1 a flexibility approaching that of speedlights. The question then inevitably comes up just how much stronger the Profoto B1 is than a speedlight. Stated in another way: how many speedlights would you have to gang up to match 500Ws of studio light output?
Let’s see then how studio lights compare to speedlights / speedlites in terms of output.
I had a model, Melanie, in the studio to do a series of test photos. I used a Nikon SB-910 Speedlight (affiliate) vs a Profoto D1 Air 500Ws studio light (affiliate). The studio-bound Profoto D1 is similar to the B1, except that the D1 doesn’t run off a battery.
500Ws is a typical power rating of this kind of studio light. For this comparison, keep in mind that the Nikon SB-910 Speedlight (affiliate) has the same output as the Canon 600EX-RT Speedlite (affiliate)
1.) Direct flash
Comparing the Nikon SB910 set to 50mm zoom, and 1/1 manual output … vs the Profoto D1 at full output.
I had both flashes at 10 ft away from Melanie, who stood a few feet from the studio wall. The speedlight offered a surprisingly small aperture value for that central spot. About 1 stop under the much more powerful D1 / B1. Yet we can clearly see just how wide the Profoto D1 throws its light. So there is obviously a lot more light coming from the Profoto head than just what would give correct exposure for a small central area.
Notice that the shadow behind Melanie is less pronounced with the Profoto D1 head, because of the amount of light being bounced around the place.
As an aside: the exposure values for the SB-910 very closely matches what we’d expect from the guide number. Check this tutorial on how to use the guide number of your flash.
The next step would be then to use a light modifier for both flashes, and see where we end up.
2.) With a flash modifier
Adding the huge Westcott 7′ Parabolic Umbrella (affiliate), equalized the comparison between the studio light and the more compact speedlight. Here is the review of the Westcott 7′ Parabolic Umbrella.
This light modifier is massive and would spread the light quite widely. I added the inset photo to show how wide the light from either flash spreads into the umbrella. This didn’t appear to have an obvious effect on how evenly the parabolic umbrella spread the light into the studio area.
Now we get a better sense of the actual output of the respective flashes. The 500Ws juice from the Profoto D1 gave us nearly 3 stops more output when used like this. (Actually, it appears closer to 2.7 stops, judging by the light-meter and the photos.)
This implies, that to get the same exposure (with the same light modifier), we’d have to gang up 6 to 8 speedlights to match 500Ws.
This might seem like an unequal comparison, but a speedlight will most likely always be your best option for portable lighting. Small and powerful. A top-of-the-line speedlight is very sophisticated, with TTL capability and high-speed flash sync. Every photographer should own a few.
For sheer brute power though, it can’t match a studio-type light. And this is where the Profoto B1 battery powered flash (affiliate) shines. True wireless control and with TTL capability, it becomes very easy to use and set up on location.
This also takes us in an interesting direction. It is quite often mentioned that powerful portable lights such as the Profoto B1 are quite expensive. But if you break it down into a comparable number of speedlights and wireless transmitters (and possibly battery packs), then the all-speedlight option becomes quite expensive as well. An interesting consideration.
- tutorial: How to use the guide number of your flash
- Getting the most power from your flash
- Photographing in partial sunlight & shade
- Using the Profoto B1 flash at a wedding
- Which is the best flashgun, and what should I buy?
- review: Westcott 7′ Parabolic Umbrella (model: Ulorin Vex)
A little bit of homework
- Why would a 3-stop difference in output equate to having to use 8 speedlights to match the studio light?
- Adding up all the accessories you’d need with multiple speedlights (and wireless triggers and battery packs) and a clamp to hold multiple speedlights – how would this compare price-wise to a single Profoto B1 ? (And yes we all have a few speedlights already anyway, it does help equal out the final figures.)