I’ve lost track of the number of people who’ve asked me how to shoot this type of photo over the years. The basic concept is quite simple, although it can be difficult to wrap your head around if you’ve not used flash in such conditions before. In this video, photographer Eric Floberg talks about how you can achieve this effect in-camera. While the principle is pretty straightforward, it’ll definitely take some practice.

The great thing about shots like this is that as well as having a vibrant look, you can create them with just about any DSLR or mirrorless camera quite easily. All you really need is a wide-ish lens and a speedlight, and a bit of practice.

Whenever you’re working with flash and mixing it with the ambient light, you’re essentially making two exposures simultaneously. One to build up the ambient light levels to whatever level of exposure you’re happy with, and then a fast pop of flash to make up the difference where you need it. In-camera, these two exposures result in a single final image. For shots like this, the trick is to have that ambient exposure underexposed with a really long shutter. This allows those bright lights and lasers often seen at nightclubs, wedding receptions and parties to create streaks. Depending on the look you’re after, you can go with anywhere from half a second to a couple of seconds to get those light trails and a bit of detail in the dark environment of the venue. You’ll also want to play with your ISO and aperture in order to balance the bright light sources with the overall illumination in the room. Then, a flash on your hotshoe or just off to the side when you’re close to your subject lights them up and makes them stand out from their surroundings without lighting up too much of the environment around them. Zooming your speedlight’s head to its maximum focal length will help to focus the light a bit. Snoots and grids can also be very handy to help further isolate the light on your subject. This is one of those situations where TTL can be very handy, too. Although, if you understand manual mode, and you’re able to consistently keep the same distance between yourself and your subjects, then manual is definitely a good way to go. You can also add gels to your flash and adjust your white balance to get even crazier effects. Putting a CTO gel on your flash and white balancing for tungsten can help to turn the lights of the environment blue while still having a nice neutral or warm look for your subject. Going the other way with a CTB gel, it can warm up the environment to give a more intense look to your subject. It can make for a very cool final result and one that I don’t get to shoot anywhere near as often as I’d like. But that’s probably mostly down to my dislike of weddings. And parties. And people in general. [via FStoppers]