Photographing
Projectile Points
A Guide by Niko Silvester
Photographing
Projectile Points
A Guide by Niko Silvester
| Introduction | Although this guide is primarily geared
towards photographing points, it can also be applied to other knapped and
ground stone tools. Some adjustments to the principles outlined here may
be needed if the objects to be photographed are large, but the basics are
the same.
When photographing your projectile points, you will need to use a magnification of 1:1, ie. life-sized on the developed print, or larger in order to show the details of your work. You can enlarge prints with lower magnification, but the results will not be as nice as if you take the photo that way to start with. |
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| Camera | The best kind of camera for close-up
photography is a large format camera, say 5x4 or larger. These are professional
cameras, and can be quite expensive, so I will skip over them. (Besides,
my own experience with them is purely theoretical) (And anyone who owns
one probably knows more about photography than I do anyway).
Any good 35mm camera (but not the "point-and-shoot" kind) will take quite adequate (and often much more than adequate) close-up photographs. Canon, Pentax, and Nikon are good because lenses for them are plentiful, and usually easy to come by for a reasonable price. Other brands are probably just as good, but it may be harder, or more expensive, to get lenses. "Point and Shoot" cameras, cameras that do everything for you, and those handy little disposable cameras aren't a very good choice, as things normally have to be so far away from them to be in focus that small objects like projectile points are reduced to tiny specks. |
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| Lens | If you really want to take good close-up
photographs you will need a macro lens for your camera. These lenses are
capable of focussing at much closer distances, and even of enlarging the
object on the film. Macro lenses come in various sizes, and the best size
for you depends on how big the objects you want to photograph are. A good
size is 50mm.
There are less expensive alternatives to buying a macro lens (though if you plan to do a lot of photography, I would recommend the macro). The cheapest alternative is an extension tube, which can be used with the standard 50mm lens that is sold with most 35mm cameras. This fits between the body of the camera and the lens, and functions to increase the magnification of the image. You can get them in various lengths- the longer the length, the higher the magnification. The main problem with extension tubes is that they tend to reflect light inside the tube, which can result in spots of reflected light in the centre of the photograph. Thus you have to be careful about excess lighting. Another alternative, which functions about the same as an extension tube, is a bellows unit. The advantages of a bellows over an extension tube is that a bellows unit allows a higher magnification, and more flexibility, and does not have the problem with reflected light. They are more bulky and more expensive, however. The final alternative to a macro lens is a so-called macro-zoom lens. Many hobby photographers already possess zoom lenses which can give an enlargement of 1:2 at their shortest focal length. These are not as good as real macro lenses, however, but give about as good close-up resolution as a standard lens with an extension tube. Ordinary zoom lenses can also be used to photograph small objects by placing the object on the ground, and using the zoom function of the lens to magnify the image. This results in generally poor resolution, however, and is probably not even as good as a standard lens with an extension tube. |
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| Tripod | It is probably a good idea to use a
tripod or copystand. It may not be entirely necessary if there is enough
light to take the photograph at a high shutter speed, but magnifying the
image also magnifies any movement of the camera. Thus, you will probably
find you get much better results with a tripod or other device for holding
the camera, especially as you will be taking the photograph from directly
above the object.
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| Film | Black and white film can be useful
for showing details on the surface of an object, but most people will probably
want to show off the nice colours of their points as well. Slide film is
good for those who are into giving public lectures, and tends to have better
resolution than print film (as it has to be magnified by the projector).
I imagine most people will want to use colour print film, however. To get
the best results with close-up photography, a lower film speed is best,
especially if you are going to want to enlarge your prints. Something with
an ASA/ISO of less than 100 is preferable (50 ASA/ISO should be good),
though you can probably still get adequate photographs with 100 ASA/ISO.
Most colour print film is made for use in daylight, but if you are using lamps, you can buy film specially balanced for tungsten light (see more about tungsten light in the "Lighting" section). |
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| Background | A neutral colour is the best all-purpose
background (grey, or a subdued colour that goes well with the colours of
the points). Black or white can also be good choices. Make sure the background
area is not too large or too brightly lit (especially if it is white),
as this will over-light the edges of the object. For very small objects,
especially if your background is textured, like cloth, it may be a good
idea to elevate the objects above the surface a little to throw the background
out of focus. You can use a little blob of modelling clay to do this.
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| Scale | Because the sense of size can be lost
in a photograph, you may wish to use a scale. For something as low-relief
as a projectile point, a ruler or other linear scale is probably the best
choice. If you want to be accurate, make sure the surface of the scale
is level with the edge of the point, and not the bottom surface. Objects
of known size like coins or standard-size business cards are also fine
if your photographs are not for use by anal-retentive scholars, but to
show off your work.
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| Lighting | You can probably get decent results
taking your photographs in natural light, which has the advantage of not
needing any special requirements, but the disadvantage of not being very
flexible. Bright sunlight is generally too harsh, but diffused sunlight
can work quite well. However, if you want good control over the direction
of illumination, you will probably want to use artificial light. Most artificial
light is made by a glowing tungsten filament, which is a different temperature
than sunlight, and needs a little special preparation to avoid getting
photographs with too much orange. Tungsten-balanced film may be hard to
come by (likely only found in specialty shops, and more expensive than
regular daylight film), so you may want to use a blue filter instead. You
can either put one over the light source (try blue cellophane), or on the
camera lens (which will probably give better results than the cellophane,
but which will cost more). There are various ways of lighting an object,
which will give various results, such as lighting it from underneath to
produce a halo effect. However, the most practical method for those of
us without access to special lighting apparatus is to light the point from
one end. You can try various angles to determine which best highlights
the features of the particular piece, but an angle of 20-50 degrees to
the horizontal will usually give the best results. You will also need to
use a deflector (white Styrofoam is excellent) at the opposite end of the
piece to diffuse the light a little, and reflect some of it back. This
results in the ridges and flake scars on the object being clearly shown,
but not too exaggerated.
If your points have thin, translucent or transparent edges, or are made entirely of obsidian, you will probably find that the edges are extremely hard to see on the developed print (if you can see them all). You can avoid this by painting the back of the point with a water-based paint. The paint makes the edges of your points show up nicely, but will wash off easily afterwards. |
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| Aperture and Exposure | The aperture, or f-stop, should be
determined before the exposure time (shutter speed), as it is what determines
the depth of field (ie. how much of the object is in focus). The higher
the f-stop, the better the depth of field, but the poorer the resolution.
The f-stop you choose will, in large part, depend on the magnification.
If you have a good macro lens and are taking the photograph at a magnification
of 3x actual size, the depth of field possible will be very shallow, so
you will want a high f-stop (22 or more, perhaps). If you are using a standard
lens and extension tube to take the photo at actual size, an f-stop of
11 should be sufficient. You will be able to tell when you are focussing
if your depth of field is sufficient. If it is too shallow, try increasing
the f-stop.
Once the f-stop is determined, your camera's light meter will be able to give you the correct shutter speed if it is a through-the-lens meter (most basic 35mm cameras are equipped with through-the-lens light meters). If you are using an external light meter, you will need to compensate for the effects of magnification. In either case, you need to turn off any background lighting (but not your source of illumination for the photograph) before taking the reading to avoid underexposing the film. |
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| References | Dr. Gerald Newlands and his Archaeological
Photography seminar at the University of Calgary are responsible for almost
all of what I know about photography.
The following book has also been invaluable for writing this Guide:
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Comments and questions on this Guide should be addressed to Niko Silvester at [email protected]. Feel free to copy or print this for personal use. |
Knappers Anonymous was prepared by Tim Rast