Is shooting multiple exposures the best way to do night portraits with the E-PL1?

Question

I recently had the experience where I was attempting to get a night portrait of someone but still maintain some of the background. For example, getting an image of someone on top of Rockefeller Center in New York while also getting lights from the city below. Back when I had an old Canon film SLR, there was a setting where it would double expose a single picture, taking a longer exposure first for the background, then firing the flash for the second exposure to light up the subject. All done with a single click to minimize shaking.

Is this the best way to capture such a photo?

If so, anyone know how to do it on an Olympus E-PL1? It's got a setting for multiple exposures, but the only way to do this is to take a long exposure, pop-up the flash, take the flash exposure. This results in a good deal of shaking and seems like it's less than ideal for something that seems like a moderately common scenario.

Answer 1

With a flash that has TTL control you can just set a long exposure time and let the camera turn off the flash when the foreground is sufficiently exposed. The shutter will be open for the specified time and let in the light from the background. I don't know if you can use this method with your camera.

Left: 1/60 s. f/4.0
Right: 1.6 s. f/5.0

alt text http://www.guffa.com/Temp/flash.jpg

Answer 2

You really don't need multiple exposures. When the flash goes off, it does so only for a very brief period of time, so it acts like the second shot did with your previous Canon camera. So, if you set a long exposure time with the flash, your subject will be lit up (and recorded) when the flash goes off, then the background will be exposed for the rest of the time that the shutter is open.

If you find ghosting of your subject because the shutter's open long enough to record them once when the flash goes off, then again while the shutter remains open, then you can have them run out of the frame after the flash fires.

Answer 3

Multiple exposure is not the way to achieve this. A better technique is to use slow shutter sync.

Slow Shutter Sync

There are two basic ways in which a camera can take a flash photo when light levels are low. The camera can either use a short shutter speed to minimize camera motion blur and have the flash blast out enough light to illuminate the foreground objects whilst leaving the background dark, or the camera can extend the shutter time to allow more of the background to show up and flash-illuminate the foreground subject. This latter technique is called slow sync, slow shutter sync or “dragging” the shutter.

A typical example is a tourist snapshot of someone standing in front of a famous landmark at night. If you keep the shutter speed fast then you’ll have a nice flash-illuminated photo of your friend against a pitch black backdrop, unless the landmark is extremely brightly lit or unless you’re using very fast film or a high digital ISO.

However, by slowing down the shutter speed you can take a photo of the person standing against a properly exposed background at night.

The drawback is obvious, of course. By slowing the shutter speed you’re going to need a tripod to avoid blur induced by camera movement, especially with long shutter speeds like 1/15 second or slower.

Olympus PEN Specific Setting

On the PEN the setting you are looking for, located within the flash settings menu, is called "Slow".