mrdunu wrote in post #13660175
So i've been trying to "master" the art of night photography, but it seems like I'm going no where. Here's a quick shot that I took on NYE, hoping to get a sharp image of both my subjects and the ambient light from the harbour bridge.
But as you can see, I've failed miserably. My question is, how do people take night portraits? If I was to increase my shutter speed, I'd get no ambient light. If I was to slow down my shutter speed to capture the ambient light, I'd get subject movement. And even with the rear curtain flash, you don't get as sharp of an image as possible.
My analysis goes like this:
It's going to be very difficult to get both the bridge and the subjects to be "sharp" or in focus. They're just so far apart, you would have to use a very tiny aperture (large f-stop number) to even come close to having the subjects and the bridge in focus at the same time. With f/2.8, it's not gonna happen.
If you close down the aperture to get more depth-of-field (more stuff in focus) then you're losing light. You'd either need to crank up the ISO, or use a longer shutter speed - neither of which are particularly desirable for portraiture. However, if there's not much ambient light falling on your subjects, then you CAN use a longer shutter speed to expose for the bridge, then use a flash to expose your subject. The flash fires much faster than the shutter or your subjects' movement, so you'll still get the subjects crisp even with a long shutter speed (as long as the focus is correct, that is). The key is that the ambient light falling on your subjects must be minimal, to avoid "ghosting" - so make an effort to NOT pose your subjects near any light sources, streetlights, etc.
Make sure to focus on the subjects. Focus on the eyes, or as close to the eyes as you can get. With a wide aperture (f/2.8) the background will fall out of focus. For portraiture, that's okay - you want the attention to be on the subjects, so if the background is a little out of focus that's generally quite acceptable.
If you want a fool-proof way to get the subjects and the background sharp, then use a tripod, make two exposures and merge them in Photoshop. Make one where you focus on the subjects and light them appropriately with flash, then make a second exposure where you focus on the bridge and use a long shutter speed.