Plugged In: Get high results from low-light photography

By Joe Kashi, for the Redoubt Reporter

Modern digital cameras now allow even casual photographers to reliably make low-light photos considered virtually impossible during the film era. This week, we’ll discuss the basics of modern, available-light photography and the right sort of gear.

During the film era, ISO 400 Tri-X, black-and-white film was standard. In a pinch, Tri-X could be chemically processed to the equivalent of ISO 800 to ISO 1600, but the results were “gritty” with a great deal of graininess, stark contrast and poor shadow and highlight detail. Making a usable print from such negatives required experience, skill and luck. Color film was even worse, with uncorrectable color shifts in addition to the many sins of “pushed” black-and-white film. Small black-and-white images printed on low-resolution, low-contrast newsprint were forgiving, though, and push-processed Tri-X was good enough for most low-light photojournalism.

Recent full-frame, APS-C and Micro Four-Thirds digital cameras punch through that ISO ceiling, providing clean images with good color and detail at ISO 3200 and beyond. That’s liberating, allowing good photography in conditions not previously feasible for anyone not working for a three-letter federal agency.

Available-light photography is generally considered preferable to using flash, assuming that good image quality is retained. Available-light images tend to be less harsh and appear more natural. If the light’s impossibly dim, though, then electronic flash is necessary.

Electronic flash may be ineffective in some situations, resulting in photographs that appear unnaturally contrasty and harsh. Using flash is inherently obtrusive, often not in keeping with low-key social gatherings or discrete news coverage. Electronic flash, especially a single on-camera flash, often results in blown highlights, particularly facial skin, and inky-black shadow areas because the light drops off quickly.

Fast-forward to the digital era. Our expectations are higher. Even 1200-pixel web images are now expected to exhibit better technical quality than high-ISO film photographs.

Several basic digital technologies combine to provide good available-light capabilities. Modern sensors combined with RAW image formats and effective post-processing software are the most critical. Sensor quality continues to improve rapidly, so using recent gear is usually better.

Effective image-stabilization hardware helps a great deal in dim light, at least if your subject is not moving quickly. Even if a speaker’s rapidly gesturing hand might be blurred, the rest of the photo is, hopefully, reasonably sharp when image stabilization does its job.

It’s surprisingly difficult to achieve precise manual focus in dim light, so effective autofocus is important. The phase-detection autofocus used by digital SLR cameras usually works better in very dim light than contrast-detection, autofocus hardware found in most mirrorless cameras. On the other hand, mirrorless cameras use electronic viewfinders and bright rear LCD screens that are often easier to use in dim light because their brighter image aids composing the photo.

Consumer-grade zoom lenses are usually not suitable for high-quality, available-light photography. Their modest maximum apertures are usually too dim to allow sufficient light to strike the sensor and they’re usually not very sharp at those modest maximum apertures. With such zoom lenses, good image quality usually requires closing the lens one or two EV, further reducing the already-sparse amount of light reaching the sensor.

Given the above, what photo gear works best for handheld, available-light situations? Most importantly, use a camera built around a large sensor with good high-ISO performance. Smartphones and similar, small-sensor consumer cameras are not very suitable. Their small sensors and slow lenses simply can’t gather enough light. That may not matter if you’re simply posting web-resolution selfies.

Many of the 16-megapixel dSLR and mirrorless models still seem the best balance of cost, size and effectiveness for available-light use. So long as a camera can produce a fairly clean final image when used at ISO 3200, then it’s probably suitable for available-light photography in most situations if equipped with the right lens.

Full-frame, pro-grade cameras are, of course, best in low-light situations, but except for Sony’s interesting new A7 series cameras, full-frame models tend to be very large and expensive. Nikon’s D7000, Fujifilm’s X-series and Pentax’s K-5 series stand out as excellent low-light APS-C cameras through at least ISO 3200. Among compact Micro Four-Thirds models, Olympus’ OM-D E-M1, E-M5 and E-P5 models are effective because they use both a Sony sensor known for its excellent high-ISO capabilities and an effective image-stabilization system that sometimes allows me to get sharp, handheld shots as slow as one-quarter second.

Very few dSLR zoom lenses are suitable for available-light photography, the sole affordable exception being Sigma’s sharp, bright, 18- to 35-mm f/1.8 zoom available for Nikon, Canon, Sony and Pentax APS-C cameras. If you plan to do a lot of available-light photography in situations where you’re close to your subject, then this is the zoom lens to get. That versatility and image quality come at a cost, though. This is a large, heavy lens retailing at $800, which is actually a very fair price for what you get.

Modern single-magnification “prime” lenses make more sense here. They’re brighter, smaller and less expensive than zoom lenses, and usually sharper at the wider apertures needed for versatile available-light photography.

Nikon’s newer, more affordable G series dSLR lenses are suitable, as are the Sony 50-mm f/1.8, Pentax’s high-end “Limited Series” prime lenses, and Pentax’s affordable 35-mm f/2.4, and 50-mm f/1.8 optics. All of these lenses should be stopped down at least 1 EV (one “f/stop”) for best image quality, but at least you’re starting from a wide, bright maximum aperture.

Older, film-era f/1.4 lenses tend to be soft until about f/4. Sigma’s new 35-mm f/1.4 and 50-mm f/1.4 “Art” series lenses are superlative, considered to be among the best lenses made for digital cameras. They’re large and expensive, about $900 each, and available in Nikon, Canon, Sony and Pentax mounts.

The real action in sharp, bright prime lenses is found among mirrorless cameras, especially Fujifilm X-series prime lenses and Micro Four-Thirds lenses from Olympus and Panasonic. Fujifilm’s newer APS-C cameras like the X-T1 and X-E2 mount some quite excellent wide-aperture optics.

However, neither Fujifilm cameras nor their fast prime lenses include image-stabilization. That’s also true for Panasonic’s otherwise excellent Micro Four-Thirds cameras and Panasonic’s wide-angle to normal prime lenses. That may be a deal-breaker for available-light photographers. It was for me.

After much research and balancing of pros and cons, here’s what I purchased for my own available-light use:

  • Two Pentax K-5 APS-C cameras with optional manual focus screens and good, in-body image stabilization, along with a variety of Pentax Limited Series prime lenses and an f/2.8 Tamron zoom. The K-5 series still has some of the best high-ISO, low-light sensor capability of any affordable dSLR.
  • An Olympus E-M5 and an E-P5, both of which do very well at ISO 1600 and more than adequately at ISO 3200. Both models include effective, five-axis, in-body image-stabilization hardware that provides an extra 1EV to 2EV protection against camera shake at very slow shutter speeds. For available-light work, I use Panasonic 14-mm f/2.5, 20-mm f/1.7 and 25-mm f/1.4 wide-angle to normal prime lenses, along with a trio of Olympus f/1.8 lenses, a 17-mm wide-angle lens and 45-mm and 75-mm telephotos.

Available-light photography is one of the few areas of modern photography where the “right” gear really does make a difference. In a later article, we’ll talk about how to best use that gear.

Local attorney Joe Kashi received degrees from MIT and his law degree from Georgetown University. He has published many articles about computer technology, law practice and digital photography in national media since 1990. Many of his technology and photography articles can be accessed through his website, http://www.kashilaw.com.

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