Snow

On my last two photo safaris we encountered situations where our photo subjects included large expanses of snow. I was immediately deluged with questions about making correct exposures. After rather lengthy conversations I realized that photographing predominantly white landscapes is still a mystery to many tour participants. Lets go over what camera meters do, and discuss how to deal with "white subject" exposure problems. Meters do not tell you the aperture/shutter speed values to use for correct exposure. Let me define "correct exposure." It means getting a slide back with your subject rendered as you wanted it to appear. If you want the medium blue sky to record as a medium blue, and indeed it is that tone on the film, then youve made a correct exposure. If you want the white snow to record as white, and it has, then youve made a correct exposure. If you want to leave the lens cap on while you take a picture, and you have, then youve made a correct exposure. "Correct exposure" has nothing to do directly with the meter reading values; it has all to do with your choices in making the picture. Most current cameras offer a choice of three metering modes: a spot meter (which reads a very small section of the frame), a center-weighted meter (which reads the central portion) and a matrix or evaluative meter (which Yellowstone frost divides the frame into many small sections and evaluates them). fog: I metered the These three choices are available in both the manually set brightest white area, exposure mode (where you actually set both shutter speed and about 1/3 way up the aperture) and all the auto-exposure modes (aperture priority, right hand side of shutter priority and program), and are independent of AF or the frame, then manual focus. opened up 2 1/3 When you use the spot or center-weighted patterns, the meter stops. tells you what shutter speed/aperture settings to use IF you want to render the subject youre pointing the meter at as a medium tone. This is not always true for "matrix" or "evaluative" metering patterns in current Nikon and Canon cameras. These metering modes run a software program to arrive at a final exposure value; they are biasing the suggested exposures according to their programs. So lets go out and meter something. If youre working on averagetoned subjects you should have no problems. Most things are average tonality, neither light nor dark in tonality. Point your camera at the subject, take a meter reading and press the shutter. But along comes a white subject, such as a snowy scene, and now you have a problem. The absolutely worst thing you can do, in terms of exposure with slide film, is to burn out the highlights. Think about this: in our everyday lives we are used to seeing blocked-up black shadow areas with no visible detail in them. But we rarely encounter burned-out blank highlights completely devoid of detail. Thats our experience of life, so we need to record some detail in the whites on our film.

If you simply point your camera at the white area, meter using either the spot or centerweighted patterns, and shoot at the suggested exposure values the whites will, of course, be rendered as a White Sands National medium tone. You have to add some light to the Monument, rabbitbrush in suggested exposure. autumn: White Sands is one of my favorite locations, but one What about the "matrix" and "evaluative" patterns where precise metering is touted by the camera manufacturers? If you meter a mandatory. Here I metered the white area using one of these patterns, will the results brightest white in the frame, record as white? Will the software programs recognize just below the furthest left an entirely white scene and expose it as such? Lets try section of rabbitbrush, then it. Set your camera to the manual exposure mode and opened 2 stops from my spot meter a sheet of white paper (fill the frame with the meter reading. paper) using the spot-metering pattern. Center your meter display to the zero point, and you know that the film would record the white paper as a medium gray. Now, without changing anything else, switch your camera to the center-weighted metering pattern. The finder display should still read out at the "zero" position. Once again dont change anything else, but now select the matrix/evaluative metering pattern. What happened to the suggested exposure values? Did they change? I tried this test using a Nikon F5, a Nikon F100, and a Canon EOS1n. All read out the exact same exposure values as did the spot and center-weighted patterns. Matrix programs do bias the exposure if you have a range of tones within your scene, but apparently do not if youre metering only white. So, if none of these metering patterns will render a white subject as white, then what do you do? You have to open up to allow more light to hit the film. But here comes the big question: how much do you need to open up from the base reading? Torres del Paine: Here's a very All color slide films can hold detail in a range of contrasty scene. The wind was roughly five stops. From a medium placement (the extreme, with the sky/cloud meter reading, that is) one stop open gives you a "light" patterns ever-changing. The tone. This is the tone of dry sand, the palm of your one constant was the lenticular hand, white bread lightly toasted, or beige file cabinets. cloud just above the middle Two stops open yields pure white, but still with detail. peaks. I spot metered it and Two and a half stops open renders the subject as detail- opened up 2 full stops. less white. FYI, this last is exactly the tonality of the white side of a Kodak gray card. According to Kodak it has 90% reflectance. Remember that stops are doubles and halves. If 18% reflectance is medium, then 36% is one stop lighter, 72% two stops lighter, and 144% (if there were such a reflectance) three stops. In a geometric progression, 90% is half way in between these last two values. So just how white do you want your white subject to

be? For example, we speak of snow as "white" but its really all sorts of tones, depending on whether its in shadow or bright sunlight. So heres the answer: choose one specific area of your scene (I would pick the brightest "white" area, since you want to hold detail there), spot meter it and only it, then place that particular area as the tonality you want it to record by opening up accordingly. Read that sentence again as its the sure answer to exposing for whites. I would strongly suggest that you use spot-metering — so you dont accidentally meter adjoining areas — and in the manual exposure mode — since what you set is what you get without the necessity of holding down exposure lock buttons. Meter the bright area, decide how white you want it to be and open up accordingly. Ive heard it suggested that to hold detail in whites you should only open up one stop. As I mentioned, this is roughly the tonality of white bread lightly toasted. OK, is your "white" subject lighter or darker than that slice of toast? If its lighter and Ill bet it is then you must open up even more. Dont worry; youll still have detail in that subject. I think you need to open up at least 1 2/3 stops to record white as white. I would go all the way to two stops open for a bright white. By the way, if youre photographing a snow scene on an overcast, day youll need to open up even more. In this lighting situation there is no detail in the snow surface at all, since it is the shadows caused by direct sun that give that sparkling effect. On an overcast day the snow is a detail-less white to your eye, so meter it and open 2 Polar bear: I metered the bear 1/3 to 2 1/2 stops. Jack Dykinga, who I think is the best and opened up 1 stop. I 4x5 landscape photographer around, states the checked my exposure by following in his new book Large Format Nature metering the ice just below the Photography (Amphoto, 2001): "You can meter off bear's front feet and placing it white areas [note: Jack uses a spot meter] and open up 1 1/2 stops open. your lens from 1.6 to 2.3 stops, depending on how white you want your whites to be. For example, in shooting snow scenes I meter the snow in soft overcast light and open the lens 2 stops if I want the snow slightly bluish or 2.3 stops for pure white snow." Look at my photo of a polar bear, taken on the 2001 Svalbard trip. Polar bears are not white; they are cream colored, about one stop lighter than medium. But the snow is lighter than the bear. If you metered the snow and opened up only one stop, what tonality would the bear appear to be? Roughly a medium tone, that is a middletone gray; but polar bears are not average in any way. To properly expose the scene either meter the bear and open one stop or meter the snow and open two stops. Both methods will give you the same exact answer in terms of the actual shutter speed/aperture combination. I would urge you not to use an incident meter when youre photographing white subjects or working snow scenics. An incident meter measures the light falling on the subject, and gives you the same answer as metering a gray card would. But this does not work well when your subject is predominantly at one end or the other of the tonal scale.

Think about this: the old "sunny f/16" estimated exposure rule, the same as an incident reading in bright sunlight, works for medium-toned subjects but not for white or black subjects. For both of these you must add or subtract a stop of light. The best way to work white subjects is to spot meter a specific area, decide just how white you want that particular area to be, then open up accordingly. To sum up, here are my suggestions: 1. Set your camera to the spot-metering pattern in the manual exposure mode. 2. Meter the brightest "white" area and only this area. 3. Open up a minimum 1 1/2 or 1 2/3 stops. 4. On overcast days, open up 2 to 2 1/2 stops.

Tips on shooting snow and ice · 1 Jan 2002 Tips on shooting snow and ice - A complete guide to photographing snow and ice by ePHOTozine's Peter Bargh. Learn how to expose and compose in our winter months. Winter brings a new range of photo opportunities where familiar colourful scenes are suddenly covered in a blanket of snow. Bare trees become stark outlined silhouettes against a brilliant white backdrop, grasses poke out from below white canopies and old barns look like sets from pantomimes. Words and Pictures Peter Bargh As the snow falls, if you're like me, you'll probably be itching to venture out and capture the scenic delights, but beware, Jack Frost has a few tricks up his sleeve to prevent you getting good pictures. The first is the temperature. Cameras are built to work within a specific temperature range and batteries have similar needs. Most UK weather won't cause any problems, but be aware that the batteries may not perform as well as they could. Several pro-spec SLRs and medium format cameras have a special battery pack that you keep in your pocket and have a cord running up to the camera. This allows the batteries to be kept warm in your pocket while you operate the camera. If you have a model that doesn't do this try removing the batteries from the camera and warming them up before taking pictures. This is fiddly, but it may get you the extra shot or two. Also don't try and take pictures as soon as you come out of the cold into the warmth. The camera needs to acclimatise, and if pulled straight out you'll see the lens mist up. Leave the camera a few minutes before attempting to take pictures. The main problem with snow is that its brilliant and highly reflective tones fool the camera's metering system. All cameras have built in metering systems that are designed to deliver a perfect picture assuming the contrast range is normal. They do this by scrambling the tones and then adjust so the scrambled colour brightness is mid grey or average. This is fine when the subject has a wide tonal range with everything from black to white being present, but when the subject is predominantly white, such as snow, the

camera underexposes so that the white becomes grey. This also happens, to a lesser extent, on beach scenes where the sand is the main part of the subject. All you need to do is override the camera's automatic setting using the exposure compensation setting on a full auto camera or by going to manual on one of the more advanced models. If you set the exposure compensation to either plus 1 and 2 stops depending on the amount of snow in the picture your results will be much better. If your camera has an exposure lock, usually set be half pressure on the shutter button, point it at a mid tone to lock the exposure before recomposing and taking the photograph. If you have one of the old manual SLRs adjust the film speed setting to, say, ISO25 when using ISO100 film. This makes the camera allow more exposure to ensure what it thinks is a slower film receive the correct amount of exposure. Remember to set it back when you finish taking snow pictures. One final problem when you have your pictures commercially printed is that the lab can also become fooled by the tones and once again adjust to make them mid grey. Here the snow will have a brown, blue or grey hue. If so ask the lab to reprint or, better still, inform them when the films are handed in that the prints may need special attention because of the snow content. Now we have the technical details out of the way let's look at the subject. With snow pics you should try to include some areas of detail to avoid a complete wash of white. Use a telephoto lens to crop in on branches laden with snow to create lovely abstract patterns. Similarly frost or ice on leaves can pull out nature's patterns producing detail that's almost etched. Move in close and avoid flash, which will reflect off the ice and cause hard to avoid, distracting highlights. Winter mornings can provide great images. Go out before the sun melts the frozen dew. Spiders webs, icy blades of grass and frost covered berries are all great subjects to catch early in the morning. It's also worth going out as soon as the snow falls to capture virgin snow. It doesn't take long for the sledges and snowmen to eat into the freshness, making the snow a mush of brown. Look for tracks in the snow. Bird prints, paw prints and boots provide interesting detail. Shoot from an angle to ensure the print has shadows so you see the 3D shape, otherwise the impressions will be hard to see. Also try shooting while the snow is falling, but avoid flash. The light levels will be low and an automatic camera will think flash is needed. Switch it off because the flash will reflect off the nearby flakes making the picture full of large blurry blobs that distract. If you mount the camera on a tripod you can shoot at a low shutter speed and gain a real blizzard like effect as the falling snow is recorded as a blurred streak down the photo. But watch the camera! Snow will quickly melt and the water could damage the electronics. Cover the camera with a clear plastic bag with a hole at the front for the lens

to shoot through and wrap an elastic band around the bag on the lens barrel to hold it in place. Screw a filter on the front of the lens if you're using an SLR to protect the element from drifting snow. Wrap up warm and head for the fields there are some great pictures waiting.

Look around for unusual subjects that have been blessed by Jack Frost. Here the edge of a pulley is outlined with ice, making it a more interesting shape.

Winter scenes don't have to be covered in snow to affect the camera's meter. Here half a stop extra light was required to prevent the white looking blue. Frosty winter mornings produce crisp looking landscapes with dramatic skies.

Go out early on a cold winter's morning and all the leaves and branches will be etched with frost. Allow about 1/3 of a stop to compensate and ensure the frost is brilliant white.

When most of the scene is snow you must allow about 1.5 to two stops extra exposure to

ensure the snow appears pure white. But even then you may find blue in the shadow areas because snow reflects a lot of UV light that has gives the blue colour.

When shooting scenes make sure there's details such as trees or walls as well as the snow or it would be a bland wash of white. Here we show a dull version that would appear if you didn't compensate by at least one stop.

Spiders' webs look great in winter, but make sure you photograph them with a dark background to pick out the detail.