Photo Tips: Snow Exposure—Part 1

I’m not talking about stripping down and running naked through the snow. That sounds like a recipe for frostbite, hypothermia or worse! Rather, I’m focused on how to best select exposure when working in winter situations. Snow is especially difficult to work with for several reasons. First, it’s abnormally bright and results in high contrast situations that is both difficult on the eyes and the camera sensor. Second, most camera meters aren’t designed to work with fields of white, so tend to recommend the wrong settings. Third, for many photographers, making images in snow is an infrequent experience, and one that tends to lead to uncertainty and higher rates of exposure error.

Conrail at Washington Massachusetts
A blizzard blanketed the Berkshires with 3-4 feet of snow during second week of December 1992. On the morning of Dec 15, 1992, I caught a Conrail C36-7 leading a pair of SD40-2s on TV9 climbing westward through the deep cut at Washington, Massachusetts. While parking was difficult (drifts up to seven feet tall block all the usual spots, so I left the car in the road with its four-way lights flashing) the real challenge was selecting the best possible exposure for this backlit snow scene. The image was exposed using my Nikon F3T and f4.0 200mm lens. My exposure was about f5.6 1/250 second on Kodachrome 25.

My approach to snow photography stems from years of practice. In general, I take the information provided by camera meters as advisory. I rarely rely on automatic settings without some manual adjustment. Why? I’ve learned to carefully gauge exposure and apply settings manually. Furthermore, I’m distrustful of automatic metering, especially for railway photography, because the automation is programmed to deliver adequate imagery other than what I’m trying to achieve. Perhaps no other situation is as difficult for a common-meter to gauge as sunlit snow imaging.

Many years ago, my father lent me a Weston Master III, and instructed me to wander around the house making exposures and write them down. No photos were exposed. I was about nine and I found this exercise confusing and frustrating because I didn’t understand what I was supposed to be doing. However, I overcame frustration and learned to use the light meter. A decade later, I had the opportunity to learn Cibachrome printing (used to make vivid prints from color slides). At the time, I was primarily working with Kodachrome 25, which I’d been taught to nominally underexpose to produce more saturated colors.

Translating Kodachrome to Cibachrome was revealing; I’d found that my rich, slightly-underexposed slides, which when projected on a nice bright screen looked fantastic, were in fact rather difficult to print. The biggest issue was contrast. While under-exposure may have enhanced the color saturation, it also made the image more contrasty. So while it turned out that my old theory on underexposure had it flaws, I discovered that slightly overexposed slides printed very well. I needed to determine ideal exposures in order to make optimal slides.

Aiding my efforts was my notebook; I’d been recording my exposures for years, but with the Ciba exercise I began making even more detailed notes, recording slide exposures to the third of a stop. Eventually, I assembled a chart with ideal exposures for Kodachrome 25 in various lighting situations. In general, I’d discovered that to make prints, slides needed to be about 1/3 stop brighter than I’d been making them for projection. All very well, but what does this have to do with making digital images in the snow?

Exposing Kodachrome is history, but the lessons I learned from this material still apply. (The short answer to the question was that snow in bright daylight should be exposed at approximately 1 ½ stops down from the full daylight setting without snow; thus with Kodachrome 25, if my normal daylight setting was f4.5 1/250, my snow exposure was about f8 1/250 +/- 1/3 stop). Many of my slides have appeared in books, magazines, as well as here on Tracking the Light. Take a look at my recent book North American Locomotives for some top-notch printed reproductions of Kodachrome.

Digital photography offers some great advantages over Kodachrome, including the ability to review images on-site—thus removing the uncertainty of exposing slides and having to wait for days (or weeks) to see if your exposures were correct. It’s now easier than ever to make good snow exposures and learn immediately from miscalculation. Related to this is the ability to use a digital camera’s histogram as an on-site exposure tool.

Histogram? Yes! This is perhaps the greatest feature on my digital cameras. It allows me to set my exposure ideally, allowing key images to capture the greatest amount information, thus minimizing detail lost through unwanted under-or over-exposure. Positively invaluable when making images in the snow.

New England Central GP38s in Palmer.
Sunday February 10, 2013, I made this image of New England Central GP38s climbing State Line Hill at the Route 32 crossing South Monson. Nearly 61 years ago, Bob Buck exposed an image of Central Vermont 2-8-0s 462 and 468 leading a southward freight from the same angle at this crossing. There were fewer trees back then! See page 66 of my North American Locomotives for a full page reproduction of Bob’s dramatic B&W photograph.

Today, before a train enters the scene, I’ll make a series of test exposures and judge them by the output of the histogram. This allows me to refine my exposure to a point that exceeds what I could have achieved with my detailed chart and Kodachrome. In my next post, I’ll detail this process with more examples.

Histogram
On command, my Canon 7D offers a variety of useful information. Here’s the in-camera thumbnail of NECR’s GP38s crossing Rt32 in South Monson with relevant histogram as displayed on camera screen. Learning to interpret the graph is extremely useful in making exposures in difficult situations. While I’ve balanced the exposure to favor detail on the locomotives, I’ve managed to retain satisfactory levels of detail in the piles of snow both side of the tracks. The image was exposed using my Canon 40mm Pancake lens.

 

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3 thoughts on “Photo Tips: Snow Exposure—Part 1”

  1. Based on the in-camera histogram, do the three peaks I see represent the bright snow on the left, the yellow nose of the locomotive, and more bright snow on the right? (I’m a film photographer so I’m unfamiliar with histograms). What would the histogram look like without the train in the scene? I mean, once the train arrives, it’s pretty much too late to interpret a histogram, right?

    1. I’m glad to see you are anticipating the specifics of the next post! I cover some of that (with arrows and lines and everything). From my experience, the Histogram is a tool, certainly better than my old Sekonic handheld light meter and chart of Kodachrome situations, but not flawless. Brian Solomon

  2. Brian, are you going to take a picture of a histogram? I’m sure many people have no idea what one looks like.

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