snow, glaciers, ice photography hints

[quentin_smith]

i have taken heaps of photos in situations where ice, snow, glaciers

make up some or all of the subject with mixed results.

someone told me to overexpose by 1 stop.

 

i cant seem to get consistant results and would love to get some hints

 

any ideas, rules, hints

[david_henderson]

Don't do rules, do thinking. There is no generalised adjustment

that will always give you the right answer. Equally if you're using

d&p packages then it's entirely possible that "corrections" are

taking place that affect your perception of what you're getting right

or wrong, exposure-wise. It's a big subject, so I'm really just

going to be able to skim the surface of the things that matter.

 

First what film are you using? Different films have different

abilities to hold contrast. If I used an in-camera meter to take a

reading from a uniformly brightly lit patch of snow then following

that reading should result in the snow seeming to be a mid grey.

To make it look bright white with a little detail you'd probably want

to overexpose by 2 stops if using slide film; 3 stops if using

colour print film and 4 stops if using many b&w films.

 

Second what are you actually metering to base your

compensation on? Most times you're not metering just snow

and the rest of the scene is often darker than snow. Therefore

the reading you get is already indicating more exposure than for

the snow alone. This explains why most adjustments are less

than the numbers above even in bright conditions.

 

Third, how are your exposures generally. If they're not always

good then it can be the case that it's your general exposure

management that's at fault, not the adjustment.

 

Fourth. How bright do you want the snow to be? If it's dull or the

snow's in shadow you don't want to render it as a featureless

bright white if it's realism you're after. If it's blue light in a glacier

that's often about a mid-tone so needs no adjustment. The

duller the snow, the lower the adjustment in general terms.

 

Fifth , how important is it to get the snow correctly exposed vs the

rest of the picture? Remember that any adjustment you make for

snow works on the rest of the picture as well, and you need to

understand what the effect on the sky/faces etc will be.

Sometimes you might decide not to expose the snow perfectly

because it's more important to get something else right.

 

All that said, with colour film I think that you're more likely to end

up with +1 than with any other single number. If your exposures

are miles out using +1 (as against a little bit out) I'd be inclined

to suspect something else rather than the pure ability to manage

a white subject.

 

If in doubt try bracketing at +/-0.5. or even wider. It's not the most

satisfying way to get a well exposed result , but it should deliver.

[ken_dunn1]

Also color shifts often happen in snow, I guess becasue of all the white it is just easier to see. I have never had much luck with snow without blue skies behind it. I have tried to shoot frozen waterfalls in the forest under overcast and it always looks very blue and flat. Helps with digital now of course (at least the blue part). Also leave the polarizor at home for blue sky snow shots or it will look like a night shot. I always meter bright snow and open up 1 1/2 stops and bracket.

[Jerry_]

Plus the 'colder' the temperature gets, the more chance you will have a 'slow down' in the lens-lube shutter or weaker battery power to keep the shutter 100 percent accurate. Temperatures in southern Michigan are usually mild in winter, where central Alaska can become a bit rugged.

Altitude in mountains (i.e., on or near a glacier) in the winter would also equate to colder-than-normal conditions.

[ShunCheung]

If there is a spot meter on your camera or you can use an external spot meter, snow exposure is very easy. Recently I went to the Arctic region with John Shaw and he discussed this very topic which is also in his article <A HREF="http://www.photosafaris.com/Articles/ExposingWhiteRight.asp">Exposing White Right</A> on Joe Van Os' web site.

<P>

If you use slide film, since they can record 2 stops above and 2 stops below medium, you want to set the brightest area in your frame to 1-2/3 stops above medium so that this brightest area doesn't burn out (becomes totally white with no detail), and the rest of your image will be just fine. Since I sometimes prefer slightly darker images, I might open up only 1-1/3 stops. If you are not sure, you might want to bracket by 1/3 stop and get two frames just to see which one you prefer; there is a noticable difference in 1/3 stop though. However, there is definitely no need to do any major bracketing such as by 1 or 2 stops in both directions.

<P>

Here are some <A HREF="http://www.photo.net/photodb/folder?folder_id=320709">selected images from my Arctic Trip</A>.

[efusco]

Great exposure advice above.

 

I'll just add that a polarizer can be quite helpful/effective in the above situations. Be aware that glare can be a problem so use a lens hood too (something that can make using the polarizer more tricky, but is essential due to the high reflectivity).

 

The polarizer will greatly deepen the blue ice of glaciers as well, making them quite dramatic. It will also help improve the rendering of contrast on snowy surfaces.

 

Further, the advice of using a hand-held meter is good, IF you use it properly, which can be pretty dang tricky. Which way do you point it? Some say always point it toward the light source--but that will render backlit subjects as shadows, some say point it at the camera--but that can allow hightlights to be over exposed in some situations. You really have to be careful to aim the meter such that the plane of the dome of the meter is same as the plane of the subject you most need correctly exposed.

[imaginator]

Use an incident meter (measures the light itself) or just use your camera meter to measure the light reflected off a gray card. Actually, it's easier to meter the palm of your hand and compensate 1 stop (similar to what you do when metering snow, but your hand remains constant and is "handy") Bracket according to the specific situation and film used. A polarized filter is very useful, but back off the adjustment... use sparingly, especially with reflections, and don't leave it on all the time (try with and without) Snow in the open shade is a problem because most of the light is from the blue sky so it has a strong blue cast and is soft (use warming filter for slide films) As mentioned, snow reflects whatever is around it (and the sky) so try different compositions and angles (including up and down) Snow and ice are both forms of water, and water can take on the effects of many optical elements like a mirror, prism, lens, diffuser, ect. This, combined with the light, can create some real inetersting effets... walk around, look from different viewpoints. Since snow and ice tend to reflect alot of light, try to shade your lens well (someone mentioned this, but didn't go into detail... the relfected light will be from all angles, including from the ground, so consider using something in addition to a basic lens hood... hold or clamp something dark to provide shading for specific areas (mostly the sky above and the snow below) I even shade the lens when shooting in the open shade (keeps out the bright skylight)

[quentin_smith]

thanks for the advice

i will try metering on the snow and over exposing.

i assume that a grey card will work also in this situation????

 

thanks