1/180 sec @ f1.8, ISO 6400
Low light is beautiful. Often the best light of the day comes after the sun has set, especially if you are by the sea as the water acts like a giant reflector, bouncing the light around and adding to the intensity. The fading daylight may have a red or pink glow that is offset by the deep blue sky behind. It’s fleeting light, and the closer you live to the equator the quicker it will disappear.
Galen Rowell called this type of light alpenglow, and landscape photographers use tripods, low ISOs and long shutter speeds to take full advantage of it. The tripod is a necessity because by the time you stop down for depth-of-field you are looking at shutter speeds of ten seconds plus to get a good exposure. If you want to practise long exposure photography and don’t have a neutral density filter, this is the ideal time to do it (you can learn more about this in my ebook Slow).
This type of light is also good for portraits. It’s an unusual type of light to see used for taking photos of people as you are restricted by shutter speed. You need to select one fast enough to freeze movement (or a slightly slower one to introduce a little blur if you want something edgier). That means you need to use a high ISO and a wide aperture to get a good exposure.
You may be tempted to either not shoot in these conditions or use portable flash to provide light. But there’s another approach. You can take advantage of the beautiful quality of the light at this time by using a high ISO combined with a prime lens. My favourite lens for portraits is my EF 85mm f1.8 (on a full-frame camera). If you have a crop sensor camera, a 50mm prime gives you a similar field-of-view and perspective.
All the portraits in this article were taken at ISO 6400. I’m lucky as I have an EOS 5D Mark II which gives excellent high ISO performance. But so do many other modern digital cameras. If you haven’t tested out your camera at high ISOs then I suggest it’s time you do so. You will probably be pleasantly surprised at the quality of the results, especially if you process your Raw files with software like Lightroom, which is noted for its excellent noise reduction.
Let’s look at some more examples:
1/180 sec @ f2.8, ISO 6400
Note that this photo was taken at f2.8. Not the widest aperture on the lens, but still wider than most zooms. You would get a similar perspective by using an 18-55mm kit lens on an APS-C camera with the lens at 55mm, but limited to a maximum aperture of f5.6. That’s two stops less than f2.8, so you need to increase the ISO or use a slower shutter speed to compensate. You wouldn’t be able to take a portrait like this one.
So that’s one of the benefits of prime lenses, you can use them in low light for hand-held photos. The wider maximum aperture settings extend the length of time you can shoot for in the evening.
Another is shallow depth-of-field. The background in the photo is out of focus, and you need wide apertures to get that effect.
Here are a couple more portraits taken the same evening:
1/180 sec @ f2.8, ISO 6400
1/180 sec @ f2.8, ISO 6400