Natural Light Photography – Choosing Your Lens

This month, Susan Keller will be sharing her tips for taking photos indoors in a series of photography tutorials on I Heart Faces. This is the first of a 3-part series.

Natural light photography is something that’s easily accomplished out in the great wide outdoors. It’s a little trickier not to use your camera’s flash indoors, because, well, there’s simply less light than there is outdoors. So, in this short series of posts, we’re going to talk about making the best use of the light we have. And specifically in this post, we’ll be discussing your best lens options for grabbing as much natural light as possible.

Choosing a Lens for Natural Light Indoor Photography

Today, I’m going to talk lens technicalities, and show you why prime (aka “fixed”) lenses give you a slight edge over zoom lenses in grabbing light.
There are three main ways to grab as much light as possible:

1.  Bump your ISO
2.  Open up your aperture, and
3.  Use slow shutter speeds

Each way has a “dark side”: high ISOs mean higher “noise”; wide apertures can create razor thin depth of focus and chromatic aberration; and shutter speeds that are too slow can make for blurry pictures.

Prime vs. Zoom

Let’s look at how effectively different lenses grab light using shutter speed as our barometer for measurement. To that end, I’m going to use Darling Girl as my “model” (she stands still and looks consistently pretty way better than any of my wiggly dudes). Each of the following images had the same settings of 1250 ISO and f/4. All of the images are SOOC, just cropped and sized for web. Darling Girl is placed in a dark corner of my kitchen with no direct light source.

Please note: 1st piece of evidence that a prime lens grabs more light than a zoom lens. The 50mm prime lens only needed 1/100 second shutter speed to properly expose this image. That same focal length of 50mm on my 24-105mm zoom lens needed 1/60 second. Likewise, the 35mm fixed lens had a marginally faster shutter speed for proper exposure.

Long Focal Lengths

Now note: longer focal lengths need longer shutter speeds to properly expose the same image. Oftentimes this longer shutter speed will result in a blurry picture either due to camera shake or to subject movement. Also, keep in mind, that longer focal length lenses generally need faster shutter speeds to achieve sharp images (the rule of thumb is 1/x seconds where x=focal length; thus 100mm lens needs at least 1/100 second shutter speed to avoid camera shake.)

Considering ISO

One last comparison example. This time I’m dropping the ISO to 400, which is an ISO level that most cameras can comfortably handle without too much noise. I kept the aperture at f/4 so I could compare my fixed 35mm to my 24-105mm zoom (which has a maximum f/4 aperture).

Again, the prime lens required a shorter shutter speed than the zoom lens at the same focal length. Plus, I can handhold my prime 35mm at 1/30 without camera shake issues. The lowest I can get away with handholding my 24-105 is 1/80 sec (in an emergency and trying really, REALLY hard to hold still), though I’m safer at 1/125 sec (I’m not the steadiest shooter).

Summary

So. In a nutshell, these are the nitty gritty details for preferred lenses when shooting indoors utilizing natural light :

1. Prime lenses are faster and gobble light more effectively than zoom lenses at the same focal length.
2. Prime lenses generally have wider maximum apertures than their zoom counterparts. Again, good for gobbling light.
3. Shorter focal lengths (ie. 15mm, 20mm, 24mm, 28mm, 35mm, 50mm) gobble more light than telephoto focal lengths (ie. 85mm, 135mm, 200mm)
4. If you’re shooting with a zoom lens and need more light, shoot at the widest end (smallest number) of the focal length.

I’m lucky enough to have pretty awesome and abundant light in my home. But even with all the great light, I tend to leave my 35mm f/2 lens on my camera most of the time here at home. Each of the pictures below was taken with a fixed length lens (either 35mm or 24mm).

Now that you know which lenses to choose for indoor situations, you will want to stay tuned during the month of May for Susan’s other tutorials in this series on Shooting Indoors with Natural Light.

Susan Keller is an Orange County Baby, Child & Family Photographer who loves coffee, good books, big landscapes, her dudes, and using ellipses instead of words… You can find her on Facebook and blogging at Short on Words.

Tagged as: lenses, natural light photography, Photography Tips, susan keller