Introduction
Rime, ice flowers and hoar frost are easy to photograph since these structures occur
frequently on winter mornings in temperate climates.
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Snow crystals are the well-known small hexagonal ice crystals with
dendritic structure that are always depicted on anything having to
do with winter, (northern hemisphere) christmas, and such. They
are not the typical dense white snow that falls from the sky when
the temperatures are below freezing - these are called snowflakes.
Snowflakes can be large and are conglomerates of snow crystals.
Although snowflakes can grow to several centimeters across, snow
crystals are generally quite small, typically around 1 mm (1/25")
in diameter.
Photographing snow crystals is not difficult, but you need some
preparation - and a lot of patience. Apart from the fact that it
may not snow very often or for long periods where you live,
you need to have all the necessary equipment at hand beforehand.
Equipment
You will need a camera with some sort of macro-lens, able to image
an ice crystal of a few millimeter as large as
possible on the film format you use. Another easier option is to use
bellows between the camera body and a normal lens, for example, a
standard 50mm lens. Whichever setup you use, the macro function
should have an enlargement factor of around 5 or higher for typical snow
crystals imaged on 35mm film. If you use bellows or extension rings,
I recommend you to use the camera lens backward. Some camera
manufacturers (e.g. Nikon) have special adapters for this.
Other things needed are a steady tripod, a cable release,
a table, and a black piece of cloth (linen or cotton) or a piece of
black cardboard. This black card can be about 30x30 cm (1 square
foot).
To photograph snow crystals as detailed as this you will need
to photograph through a microscope. If you have everything inside a coolbox with dry ice
you will have more time before the crystal melts, evaporates or rimes. You can also grow
such crystals in the coolbox, as was done for this photo.
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Photography technique
The simplest method is as follows. While it is snowing, setup the
camera on the tripod, facing down to the table. The front lens
element must be quite close to the table surface in order to focus
correctly.
Lay down the black cardboard or cloth on the table, and look at the
crystals falling on it. Depending on the type of snow falling,
humidity, temperature, and wind, the crystals may or may not be good
for photography. Big, dense snowflakes are conglomerates of crystals
and will usually not break up nicely into good samples. It may help
to stand near to a house, downwind, where only the lightest
precipitation will fall - if you're lucky you will see beautiful
hexagonal crystals falling on the black sheet, a millimeter or so in
diameter. Other shapes you may see could be
needles, columns with or without plates at the end, and hexagonal
plates. You may need magnifying glasses to look at these small
crystals.
Study the falling crystals, and if you see a good one, shift this
under the camera lens and make a photo. You must use a fairly high
aperture setting like f/11 or f/16 in order to get adequate depth
of focus. But the aperture should not be too small to prevent
unsharpness due to diffraction.
For every photo you will need to refocus since the table and the
cloth may be irregular, and when doing macro the focal distance is
much more critical than usual. Also, it is better to photograph
only crystals that are more or less horizontal on the sheet.
Repositioning crystals can be done with a small toothpick or brush,
but they are very fragile. They will melt or blow away even from
your breath.
This is the easiest way to photograph ice crystals and snowflakes
falling from the sky. A better way is to use a microscope with
a camera adapter for photography, with which you can enlarge the
crystal much more and much easier. However, the preparation needed
to do this is substantial and expensive. I suggest trying
an easy way first, and if you like photographing ice crystals,
proceed to better methods.
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