Although portable, monolights tend to be thought of as studio solutions while strobes and flashes are often considered to be much more compact and portable, like a speedlight. Modern designs in both regards are very versatile and powerful, however, and many photographers will use these terms interchangeably.
An estimate of the power of a flash is given by the guide number, while the power of a monolight is given in Watt/seconds, the maximum amount of power generated each second by the fixture. Watt/seconds can be influenced by a number of factors in the design of the light, so it’s best to think of this number as a general classification rather than a clear specification. With top-notch color rendering, durable casings and reliable burst consistency, pro monolight systems start around the 1200 W/s range, while more affordable models capable of lighting a scene on their own start around the 300 W/s mark.
Remember, distance can matter as much as output, so monolights with a W/s rating below this can still be used quite effectively when positioned near your subject. Multiple strobe units can also be far more effective for your photography over spending a lot of money on a single high-end fixture. When working with more than one light, you can gain multiple lighting setups and more total overall illumination for faster shutter speeds and larger depth of field. When using only a single monolight or flash, on the other hand, the light produced will be highly unidirectional, which can result in a lot of contrast, heavy shadows and vignetting in the background.
The new Photoflex FlexFlash is available in 200 W/s and 400 W/s models with sync speeds of up to 1/250th of a second when wired or fired remotely. They can shoot at up to 1/320th shutter speeds when using the preflash optical sensor, which also makes the FlexFlash compatible with the TTL automatic metering modes of a camera. The 120-watt modeling light can be used proportionate to flash settings for an accurate preview, and it can be set to a continuous mode for video work. FlexFlash kits are available with multiple heads and reflective umbrellas. Estimated Street Price: $389 (FlexFlash 400w Monolite); $319 (FlexFlash 200w Monolite).
The D-Lite RX series is Elinchrom’s family of entry-level compact strobes. There are currently three lights in the line: the 100 W/s D-Lite RX One, the 200 W/s D-Lite RX 2 and the 400 W/s D-Lite RX 4. All three include functions that can be controlled from Macs or PCs through the Skyport Software or the iOS Elinchrom Skyport Wi-Fi app when used with the optional Transceiver RX module. Estimated Street Price: $225 (D-Lite RX One); $339 (D-Lite RX 2); $399 (D-Lite RX 4); $124 (EL-Skyport Transceiver RX).