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Image Plate Scale
by Roger N. Clark
| Home | Galleries | Articles | Reviews | Best Gear | Science | New | About | Contact |
by Roger N. Clark
Introduction
Plate scale is a term which originated with film glass plates used over a hundred years ago. It is usually given as angular size per unit length on the glass plate. For example, degrees per millimeter, arc-minutes per millimeter, or arc-seconds per millimeter. If the subject distance is known, it can be expressed as the linear size at the subject on the sensor, for example, meters (on the subject) per millimeter on the sensor.
With modern digital cameras, plate scale can also be expressed in pixels, as in arc-seconds per pixel. Then if one knows the angular size of a subject (e.g. the Moon, a planet, or other astronomical object), the size in pixels can be calculated. If one knows the size and distance for a terrestrial subject, e.g. a bird that is 3 feet tall at a distance of 50 yards, the size in pixels can be calculated. Alternatively, with the lens focal distance recorded in the exif data, one can determine the size of a subject, e.g. how long are the claws on that grizzly bear?
Image Plate Scale
plate scale = 206265 * pixel pitch in mm / focal length in mm (result in arc-seconds per pixel).
The 206265 is the number of arc-seconds in one radian.
Without the 206265 factor, the plate scale is in radians:
plate scale radians = pixel pitch in mm / focal length in mm (result in radians per pixel).
Subject Plate Scale = range * pixel pitch in mm / focal length in mm (result in units in range per pixel),
for example, if the range is 500 meters, the focal length is 500 mm, and the pixel size is 5 microns (0.005 mm), the Subject Plate Scale = 500 meters * (0.005mm/500mm) = 0.005 meters/pixel = 5 mm /pixel
Examples:
Nikon D800 with 4.9 micron pixels (0.0049 mm) with a 600 mm lens:
plate scale = 206265 * 0.0049 / 600 = 1.7 arc-seconds.
Canon 7D with 4.3 microns pixels (0.0043 mm) with a 500 mm lens:
plate scale = 206265 * 0.0043 / 500 = 1.77 arc-seconds.
Canon 5D Mark II with 6.4 microns pixels (0.0064 mm) with a 500 mm lens:
plate scale = 206265 * 0.0064 / 500 = 2.6 arc-seconds.
Subject Size
Subject size = #pixels length on subject * Subject Plate Scale
Subject size = #pixels length on subject * range * pixel pitch in mm / focal length in mm
Example:
A grizzly bear's claw measures 300 pixels at a range of 50 meters with a 500 mm focal length lens (0.5 meter) and 5-micron pixels. How long are the claws?
claw size = 300 pixels * 50 meters * 0.005 mm pixel / 500 mm focal length = 0.15 meter = 150 mm = 5.9 inches.
Subject Distance
Say you know the subject's size, but want to know the distance, or how to plan for a certain size on the sensor. Say one wants X pixels on the subject, and you want to know how close you need to get with a certain lens.
Angular size of the subject = plate scale * number of pixels on the subject. (result in src-seconds)
Distance to subject = subject size / tangent(Angular size of the subject in arc-sec / 3600)
Distance to subject = subject size / tangent(pixels on subject * plate scale / 3600)
Example. 500 mm lens on a Nikon D800 with 4.88 micron pixels (see table, below) has a
plate scale = 2.01 arc-sec/pixel. For a subject 2 meters long and 2000 pixels on the sensor,
the distance would be:
distance = 2 meters / tan (2000 pixels * 2.01 arc-sec/pixel / 3600)
distance = 2 meters / tan (1.1167 degrees) = 2 / 0.019492
distance = 102.6 meters
A simplification, valid for small angles, like those imaged with telephoto
lenses is to approximate the tangent by computing the size in radians.
Example:
distance = 2 meters / (2000 pixels * 2.01 arc-sec/pixel /206265 arc-sec/radian)
distance = 2 meters / 0.0194895 = distance = 102.6 meters
Note the factor 0.0194895 is very close to the correct factor of 0.019492, and I
would round the number to 0.0195 and is accurate to better than 0.1 meter, which should
be more than accurate for most applications.
One can substitute the plate scale equation into the subject distance equation, and for telephoto lenses the Subject Distance equation reduces to:
Subject Distance = subject size / (pixels on subject * pixel size / focal length)
where the focal length and pixel size must be in the same units, like mm.
Resolution
The plate scale is also often used to indicate resolution. Real resolution is slightly less due to diffraction, assuming no other aberrations (yes on a perfect 600 mm f/4 lens, diffraction at f/4 will have an effect on fine detail contrast). Below 2 arc-seconds, atmospheric turbulence will often become a factor for distant subject (even a bird at 50 yards could be affected). As one approaches 1-arc-second, atmospheric turbulence usually becomes a dominant factor in detail on the subject (e.g. A Nikon D800 + 600 mm + 2x TC is 0.84 arc-seconds / pixel).
The angular resolution equation above illustrates another factor. Photographers seem fixated on focal length. But the above equation shows to get the same angular resolution, pixel pitch and focal length are interchangeable. Thus a camera "A" with 1.4x smaller pixels than camera "B" will be no different if camera B was used with a 1.4x TC versus camera A with the same lens and no TC. And for the same exposure time, will give the same noise and also same depth of field.
Plate Scales
Table 1: Example Plate Scales
Canon 7D Mark II:
pixel= 4.09 microns FL= 10 mm plate scale = 84.36 arc-sec/pixel
pixel= 4.09 microns FL= 15 mm plate scale = 56.24 arc-sec/pixel
pixel= 4.09 microns FL= 20 mm plate scale = 42.18 arc-sec/pixel
pixel= 4.09 microns FL= 24 mm plate scale = 35.15 arc-sec/pixel
pixel= 4.09 microns FL= 28 mm plate scale = 30.13 arc-sec/pixel
pixel= 4.09 microns FL= 35 mm plate scale = 24.10 arc-sec/pixel
pixel= 4.09 microns FL= 50 mm plate scale = 16.87 arc-sec/pixel
pixel= 4.09 microns FL= 85 mm plate scale = 9.92 arc-sec/pixel
pixel= 4.09 microns FL= 100 mm plate scale = 8.44 arc-sec/pixel
pixel= 4.09 microns FL= 135 mm plate scale = 6.25 arc-sec/pixel
pixel= 4.09 microns FL= 180 mm plate scale = 4.69 arc-sec/pixel
pixel= 4.09 microns FL= 200 mm plate scale = 4.22 arc-sec/pixel
pixel= 4.09 microns FL= 300 mm plate scale = 2.81 arc-sec/pixel
pixel= 4.09 microns FL= 400 mm plate scale = 2.11 arc-sec/pixel
pixel= 4.09 microns FL= 500 mm plate scale = 1.69 arc-sec/pixel
pixel= 4.09 microns FL= 600 mm plate scale = 1.41 arc-sec/pixel
pixel= 4.09 microns FL= 700 mm plate scale = 1.21 arc-sec/pixel
pixel= 4.09 microns FL= 800 mm plate scale = 1.05 arc-sec/pixel
pixel= 4.09 microns FL= 1000 mm plate scale = 0.84 arc-sec/pixel
pixel= 4.09 microns FL= 1200 mm plate scale = 0.70 arc-sec/pixel
pixel= 4.09 microns FL= 1400 mm plate scale = 0.60 arc-sec/pixel
pixel= 4.09 microns FL= 2000 mm plate scale = 0.42 arc-sec/pixel
Canon 7D, 60D, 650D
pixel= 4.30 microns FL= 10 mm plate scale = 88.69 arc-sec/pixel
pixel= 4.30 microns FL= 15 mm plate scale = 59.13 arc-sec/pixel
pixel= 4.30 microns FL= 20 mm plate scale = 44.35 arc-sec/pixel
pixel= 4.30 microns FL= 24 mm plate scale = 36.96 arc-sec/pixel
pixel= 4.30 microns FL= 28 mm plate scale = 31.68 arc-sec/pixel
pixel= 4.30 microns FL= 35 mm plate scale = 25.34 arc-sec/pixel
pixel= 4.30 microns FL= 50 mm plate scale = 17.74 arc-sec/pixel
pixel= 4.30 microns FL= 85 mm plate scale = 10.43 arc-sec/pixel
pixel= 4.30 microns FL= 100 mm plate scale = 8.87 arc-sec/pixel
pixel= 4.30 microns FL= 135 mm plate scale = 6.57 arc-sec/pixel
pixel= 4.30 microns FL= 180 mm plate scale = 4.93 arc-sec/pixel
pixel= 4.30 microns FL= 200 mm plate scale = 4.43 arc-sec/pixel
pixel= 4.30 microns FL= 300 mm plate scale = 2.96 arc-sec/pixel
pixel= 4.30 microns FL= 400 mm plate scale = 2.22 arc-sec/pixel
pixel= 4.30 microns FL= 500 mm plate scale = 1.77 arc-sec/pixel
pixel= 4.30 microns FL= 600 mm plate scale = 1.48 arc-sec/pixel
pixel= 4.30 microns FL= 700 mm plate scale = 1.27 arc-sec/pixel
pixel= 4.30 microns FL= 800 mm plate scale = 1.11 arc-sec/pixel
pixel= 4.30 microns FL= 1000 mm plate scale = 0.89 arc-sec/pixel
pixel= 4.30 microns FL= 1200 mm plate scale = 0.74 arc-sec/pixel
pixel= 4.30 microns FL= 1400 mm plate scale = 0.63 arc-sec/pixel
pixel= 4.30 microns FL= 2000 mm plate scale = 0.44 arc-sec/pixel
Nikon D800, 800e
pixel= 4.88 microns FL= 10 mm plate scale = 100.66 arc-sec/pixel
pixel= 4.88 microns FL= 15 mm plate scale = 67.10 arc-sec/pixel
pixel= 4.88 microns FL= 20 mm plate scale = 50.33 arc-sec/pixel
pixel= 4.88 microns FL= 24 mm plate scale = 41.94 arc-sec/pixel
pixel= 4.88 microns FL= 28 mm plate scale = 35.95 arc-sec/pixel
pixel= 4.88 microns FL= 35 mm plate scale = 28.76 arc-sec/pixel
pixel= 4.88 microns FL= 50 mm plate scale = 20.13 arc-sec/pixel
pixel= 4.88 microns FL= 85 mm plate scale = 11.84 arc-sec/pixel
pixel= 4.88 microns FL= 100 mm plate scale = 10.07 arc-sec/pixel
pixel= 4.88 microns FL= 135 mm plate scale = 7.46 arc-sec/pixel
pixel= 4.88 microns FL= 180 mm plate scale = 5.59 arc-sec/pixel
pixel= 4.88 microns FL= 200 mm plate scale = 5.03 arc-sec/pixel
pixel= 4.88 microns FL= 300 mm plate scale = 3.36 arc-sec/pixel
pixel= 4.88 microns FL= 400 mm plate scale = 2.52 arc-sec/pixel
pixel= 4.88 microns FL= 500 mm plate scale = 2.01 arc-sec/pixel
pixel= 4.88 microns FL= 600 mm plate scale = 1.68 arc-sec/pixel
pixel= 4.88 microns FL= 700 mm plate scale = 1.44 arc-sec/pixel
pixel= 4.88 microns FL= 800 mm plate scale = 1.26 arc-sec/pixel
pixel= 4.88 microns FL= 1000 mm plate scale = 1.01 arc-sec/pixel
pixel= 4.88 microns FL= 1200 mm plate scale = 0.84 arc-sec/pixel
pixel= 4.88 microns FL= 1400 mm plate scale = 0.72 arc-sec/pixel
pixel= 4.88 microns FL= 2000 mm plate scale = 0.50 arc-sec/pixel
Pentax K20D
pixel= 5.00 microns FL= 10 mm plate scale = 103.13 arc-sec/pixel
pixel= 5.00 microns FL= 15 mm plate scale = 68.75 arc-sec/pixel
pixel= 5.00 microns FL= 20 mm plate scale = 51.57 arc-sec/pixel
pixel= 5.00 microns FL= 24 mm plate scale = 42.97 arc-sec/pixel
pixel= 5.00 microns FL= 28 mm plate scale = 36.83 arc-sec/pixel
pixel= 5.00 microns FL= 35 mm plate scale = 29.47 arc-sec/pixel
pixel= 5.00 microns FL= 50 mm plate scale = 20.63 arc-sec/pixel
pixel= 5.00 microns FL= 85 mm plate scale = 12.13 arc-sec/pixel
pixel= 5.00 microns FL= 100 mm plate scale = 10.31 arc-sec/pixel
pixel= 5.00 microns FL= 135 mm plate scale = 7.64 arc-sec/pixel
pixel= 5.00 microns FL= 180 mm plate scale = 5.73 arc-sec/pixel
pixel= 5.00 microns FL= 200 mm plate scale = 5.16 arc-sec/pixel
pixel= 5.00 microns FL= 300 mm plate scale = 3.44 arc-sec/pixel
pixel= 5.00 microns FL= 400 mm plate scale = 2.58 arc-sec/pixel
pixel= 5.00 microns FL= 500 mm plate scale = 2.06 arc-sec/pixel
pixel= 5.00 microns FL= 600 mm plate scale = 1.72 arc-sec/pixel
pixel= 5.00 microns FL= 700 mm plate scale = 1.47 arc-sec/pixel
pixel= 5.00 microns FL= 800 mm plate scale = 1.29 arc-sec/pixel
pixel= 5.00 microns FL= 1000 mm plate scale = 1.03 arc-sec/pixel
pixel= 5.00 microns FL= 1200 mm plate scale = 0.86 arc-sec/pixel
pixel= 5.00 microns FL= 1400 mm plate scale = 0.74 arc-sec/pixel
pixel= 5.00 microns FL= 2000 mm plate scale = 0.52 arc-sec/pixel
Canon 1D Mark IV, 400D, 1000D, 40D
pixel= 5.70 microns FL= 10 mm plate scale = 117.57 arc-sec/pixel
pixel= 5.70 microns FL= 15 mm plate scale = 78.38 arc-sec/pixel
pixel= 5.70 microns FL= 20 mm plate scale = 58.79 arc-sec/pixel
pixel= 5.70 microns FL= 24 mm plate scale = 48.99 arc-sec/pixel
pixel= 5.70 microns FL= 28 mm plate scale = 41.99 arc-sec/pixel
pixel= 5.70 microns FL= 35 mm plate scale = 33.59 arc-sec/pixel
pixel= 5.70 microns FL= 50 mm plate scale = 23.51 arc-sec/pixel
pixel= 5.70 microns FL= 85 mm plate scale = 13.83 arc-sec/pixel
pixel= 5.70 microns FL= 100 mm plate scale = 11.76 arc-sec/pixel
pixel= 5.70 microns FL= 135 mm plate scale = 8.71 arc-sec/pixel
pixel= 5.70 microns FL= 180 mm plate scale = 6.53 arc-sec/pixel
pixel= 5.70 microns FL= 200 mm plate scale = 5.88 arc-sec/pixel
pixel= 5.70 microns FL= 300 mm plate scale = 3.92 arc-sec/pixel
pixel= 5.70 microns FL= 400 mm plate scale = 2.94 arc-sec/pixel
pixel= 5.70 microns FL= 500 mm plate scale = 2.35 arc-sec/pixel
pixel= 5.70 microns FL= 600 mm plate scale = 1.96 arc-sec/pixel
pixel= 5.70 microns FL= 700 mm plate scale = 1.68 arc-sec/pixel
pixel= 5.70 microns FL= 800 mm plate scale = 1.47 arc-sec/pixel
pixel= 5.70 microns FL= 1000 mm plate scale = 1.18 arc-sec/pixel
pixel= 5.70 microns FL= 1200 mm plate scale = 0.98 arc-sec/pixel
pixel= 5.70 microns FL= 1400 mm plate scale = 0.84 arc-sec/pixel
pixel= 5.70 microns FL= 2000 mm plate scale = 0.59 arc-sec/pixel
Canon 1Ds Mark III, 5D Mark II, 20D, 30D, 20Da, 350D
pixel= 6.40 microns FL= 10 mm plate scale = 132.01 arc-sec/pixel
pixel= 6.40 microns FL= 15 mm plate scale = 88.01 arc-sec/pixel
pixel= 6.40 microns FL= 20 mm plate scale = 66.00 arc-sec/pixel
pixel= 6.40 microns FL= 24 mm plate scale = 55.00 arc-sec/pixel
pixel= 6.40 microns FL= 28 mm plate scale = 47.15 arc-sec/pixel
pixel= 6.40 microns FL= 35 mm plate scale = 37.72 arc-sec/pixel
pixel= 6.40 microns FL= 50 mm plate scale = 26.40 arc-sec/pixel
pixel= 6.40 microns FL= 85 mm plate scale = 15.53 arc-sec/pixel
pixel= 6.40 microns FL= 100 mm plate scale = 13.20 arc-sec/pixel
pixel= 6.40 microns FL= 135 mm plate scale = 9.78 arc-sec/pixel
pixel= 6.40 microns FL= 180 mm plate scale = 7.33 arc-sec/pixel
pixel= 6.40 microns FL= 200 mm plate scale = 6.60 arc-sec/pixel
pixel= 6.40 microns FL= 300 mm plate scale = 4.40 arc-sec/pixel
pixel= 6.40 microns FL= 400 mm plate scale = 3.30 arc-sec/pixel
pixel= 6.40 microns FL= 500 mm plate scale = 2.64 arc-sec/pixel
pixel= 6.40 microns FL= 600 mm plate scale = 2.20 arc-sec/pixel
pixel= 6.40 microns FL= 700 mm plate scale = 1.89 arc-sec/pixel
pixel= 6.40 microns FL= 800 mm plate scale = 1.65 arc-sec/pixel
pixel= 6.40 microns FL= 1000 mm plate scale = 1.32 arc-sec/pixel
pixel= 6.40 microns FL= 1200 mm plate scale = 1.10 arc-sec/pixel
pixel= 6.40 microns FL= 1400 mm plate scale = 0.94 arc-sec/pixel
pixel= 6.40 microns FL= 2000 mm plate scale = 0.66 arc-sec/pixel
Canon 6D
pixel= 6.58 microns FL= 10 mm plate scale = 135.72 arc-sec/pixel
pixel= 6.58 microns FL= 15 mm plate scale = 90.48 arc-sec/pixel
pixel= 6.58 microns FL= 20 mm plate scale = 67.86 arc-sec/pixel
pixel= 6.58 microns FL= 24 mm plate scale = 56.55 arc-sec/pixel
pixel= 6.58 microns FL= 28 mm plate scale = 48.47 arc-sec/pixel
pixel= 6.58 microns FL= 35 mm plate scale = 38.78 arc-sec/pixel
pixel= 6.58 microns FL= 50 mm plate scale = 27.14 arc-sec/pixel
pixel= 6.58 microns FL= 85 mm plate scale = 15.97 arc-sec/pixel
pixel= 6.58 microns FL= 100 mm plate scale = 13.57 arc-sec/pixel
pixel= 6.58 microns FL= 135 mm plate scale = 10.05 arc-sec/pixel
pixel= 6.58 microns FL= 180 mm plate scale = 7.54 arc-sec/pixel
pixel= 6.58 microns FL= 200 mm plate scale = 6.79 arc-sec/pixel
pixel= 6.58 microns FL= 300 mm plate scale = 4.52 arc-sec/pixel
pixel= 6.58 microns FL= 400 mm plate scale = 3.39 arc-sec/pixel
pixel= 6.58 microns FL= 500 mm plate scale = 2.71 arc-sec/pixel
pixel= 6.58 microns FL= 600 mm plate scale = 2.26 arc-sec/pixel
pixel= 6.58 microns FL= 700 mm plate scale = 1.94 arc-sec/pixel
pixel= 6.58 microns FL= 800 mm plate scale = 1.70 arc-sec/pixel
pixel= 6.58 microns FL= 1000 mm plate scale = 1.36 arc-sec/pixel
pixel= 6.58 microns FL= 1200 mm plate scale = 1.13 arc-sec/pixel
pixel= 6.58 microns FL= 1400 mm plate scale = 0.97 arc-sec/pixel
pixel= 6.58 microns FL= 2000 mm plate scale = 0.68 arc-sec/pixel
Canon 1DX
pixel= 6.90 microns FL= 10 mm plate scale = 142.32 arc-sec/pixel
pixel= 6.90 microns FL= 15 mm plate scale = 94.88 arc-sec/pixel
pixel= 6.90 microns FL= 20 mm plate scale = 71.16 arc-sec/pixel
pixel= 6.90 microns FL= 24 mm plate scale = 59.30 arc-sec/pixel
pixel= 6.90 microns FL= 28 mm plate scale = 50.83 arc-sec/pixel
pixel= 6.90 microns FL= 35 mm plate scale = 40.66 arc-sec/pixel
pixel= 6.90 microns FL= 50 mm plate scale = 28.46 arc-sec/pixel
pixel= 6.90 microns FL= 85 mm plate scale = 16.74 arc-sec/pixel
pixel= 6.90 microns FL= 100 mm plate scale = 14.23 arc-sec/pixel
pixel= 6.90 microns FL= 135 mm plate scale = 10.54 arc-sec/pixel
pixel= 6.90 microns FL= 180 mm plate scale = 7.91 arc-sec/pixel
pixel= 6.90 microns FL= 200 mm plate scale = 7.12 arc-sec/pixel
pixel= 6.90 microns FL= 300 mm plate scale = 4.74 arc-sec/pixel
pixel= 6.90 microns FL= 400 mm plate scale = 3.56 arc-sec/pixel
pixel= 6.90 microns FL= 500 mm plate scale = 2.85 arc-sec/pixel
pixel= 6.90 microns FL= 600 mm plate scale = 2.37 arc-sec/pixel
pixel= 6.90 microns FL= 700 mm plate scale = 2.03 arc-sec/pixel
pixel= 6.90 microns FL= 800 mm plate scale = 1.78 arc-sec/pixel
pixel= 6.90 microns FL= 1000 mm plate scale = 1.42 arc-sec/pixel
pixel= 6.90 microns FL= 1200 mm plate scale = 1.19 arc-sec/pixel
pixel= 6.90 microns FL= 1400 mm plate scale = 1.02 arc-sec/pixel
pixel= 6.90 microns FL= 2000 mm plate scale = 0.71 arc-sec/pixel
Canon 10D, 300D
pixel= 7.40 microns FL= 10 mm plate scale = 152.64 arc-sec/pixel
pixel= 7.40 microns FL= 15 mm plate scale = 101.76 arc-sec/pixel
pixel= 7.40 microns FL= 20 mm plate scale = 76.32 arc-sec/pixel
pixel= 7.40 microns FL= 24 mm plate scale = 63.60 arc-sec/pixel
pixel= 7.40 microns FL= 28 mm plate scale = 54.51 arc-sec/pixel
pixel= 7.40 microns FL= 35 mm plate scale = 43.61 arc-sec/pixel
pixel= 7.40 microns FL= 50 mm plate scale = 30.53 arc-sec/pixel
pixel= 7.40 microns FL= 85 mm plate scale = 17.96 arc-sec/pixel
pixel= 7.40 microns FL= 100 mm plate scale = 15.26 arc-sec/pixel
pixel= 7.40 microns FL= 135 mm plate scale = 11.31 arc-sec/pixel
pixel= 7.40 microns FL= 180 mm plate scale = 8.48 arc-sec/pixel
pixel= 7.40 microns FL= 200 mm plate scale = 7.63 arc-sec/pixel
pixel= 7.40 microns FL= 300 mm plate scale = 5.09 arc-sec/pixel
pixel= 7.40 microns FL= 400 mm plate scale = 3.82 arc-sec/pixel
pixel= 7.40 microns FL= 500 mm plate scale = 3.05 arc-sec/pixel
pixel= 7.40 microns FL= 600 mm plate scale = 2.54 arc-sec/pixel
pixel= 7.40 microns FL= 700 mm plate scale = 2.18 arc-sec/pixel
pixel= 7.40 microns FL= 800 mm plate scale = 1.91 arc-sec/pixel
pixel= 7.40 microns FL= 1000 mm plate scale = 1.53 arc-sec/pixel
pixel= 7.40 microns FL= 1200 mm plate scale = 1.27 arc-sec/pixel
pixel= 7.40 microns FL= 1400 mm plate scale = 1.09 arc-sec/pixel
pixel= 7.40 microns FL= 2000 mm plate scale = 0.76 arc-sec/pixel
Canon 1D Mark II, IIn
pixel= 8.20 microns FL= 10 mm plate scale = 169.14 arc-sec/pixel
pixel= 8.20 microns FL= 15 mm plate scale = 112.76 arc-sec/pixel
pixel= 8.20 microns FL= 20 mm plate scale = 84.57 arc-sec/pixel
pixel= 8.20 microns FL= 24 mm plate scale = 70.47 arc-sec/pixel
pixel= 8.20 microns FL= 28 mm plate scale = 60.41 arc-sec/pixel
pixel= 8.20 microns FL= 35 mm plate scale = 48.32 arc-sec/pixel
pixel= 8.20 microns FL= 50 mm plate scale = 33.83 arc-sec/pixel
pixel= 8.20 microns FL= 85 mm plate scale = 19.90 arc-sec/pixel
pixel= 8.20 microns FL= 100 mm plate scale = 16.91 arc-sec/pixel
pixel= 8.20 microns FL= 135 mm plate scale = 12.53 arc-sec/pixel
pixel= 8.20 microns FL= 180 mm plate scale = 9.40 arc-sec/pixel
pixel= 8.20 microns FL= 200 mm plate scale = 8.46 arc-sec/pixel
pixel= 8.20 microns FL= 300 mm plate scale = 5.64 arc-sec/pixel
pixel= 8.20 microns FL= 400 mm plate scale = 4.23 arc-sec/pixel
pixel= 8.20 microns FL= 500 mm plate scale = 3.38 arc-sec/pixel
pixel= 8.20 microns FL= 600 mm plate scale = 2.82 arc-sec/pixel
pixel= 8.20 microns FL= 700 mm plate scale = 2.42 arc-sec/pixel
pixel= 8.20 microns FL= 800 mm plate scale = 2.11 arc-sec/pixel
pixel= 8.20 microns FL= 1000 mm plate scale = 1.69 arc-sec/pixel
pixel= 8.20 microns FL= 1200 mm plate scale = 1.41 arc-sec/pixel
pixel= 8.20 microns FL= 1400 mm plate scale = 1.21 arc-sec/pixel
pixel= 8.20 microns FL= 2000 mm plate scale = 0.85 arc-sec/pixel
Nikon D3, D3s
pixel= 8.46 microns FL= 10 mm plate scale = 174.50 arc-sec/pixel
pixel= 8.46 microns FL= 15 mm plate scale = 116.33 arc-sec/pixel
pixel= 8.46 microns FL= 20 mm plate scale = 87.25 arc-sec/pixel
pixel= 8.46 microns FL= 24 mm plate scale = 72.71 arc-sec/pixel
pixel= 8.46 microns FL= 28 mm plate scale = 62.32 arc-sec/pixel
pixel= 8.46 microns FL= 35 mm plate scale = 49.86 arc-sec/pixel
pixel= 8.46 microns FL= 50 mm plate scale = 34.90 arc-sec/pixel
pixel= 8.46 microns FL= 85 mm plate scale = 20.53 arc-sec/pixel
pixel= 8.46 microns FL= 100 mm plate scale = 17.45 arc-sec/pixel
pixel= 8.46 microns FL= 135 mm plate scale = 12.93 arc-sec/pixel
pixel= 8.46 microns FL= 180 mm plate scale = 9.69 arc-sec/pixel
pixel= 8.46 microns FL= 200 mm plate scale = 8.73 arc-sec/pixel
pixel= 8.46 microns FL= 300 mm plate scale = 5.82 arc-sec/pixel
pixel= 8.46 microns FL= 400 mm plate scale = 4.36 arc-sec/pixel
pixel= 8.46 microns FL= 500 mm plate scale = 3.49 arc-sec/pixel
pixel= 8.46 microns FL= 600 mm plate scale = 2.91 arc-sec/pixel
pixel= 8.46 microns FL= 700 mm plate scale = 2.49 arc-sec/pixel
pixel= 8.46 microns FL= 800 mm plate scale = 2.18 arc-sec/pixel
pixel= 8.46 microns FL= 1000 mm plate scale = 1.75 arc-sec/pixel
pixel= 8.46 microns FL= 1200 mm plate scale = 1.45 arc-sec/pixel
pixel= 8.46 microns FL= 1400 mm plate scale = 1.25 arc-sec/pixel
pixel= 8.46 microns FL= 2000 mm plate scale = 0.87 arc-sec/pixel
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http://www.clarkvision.com/articles/platescale
First Published September 7, 2012
Last updated March 22, 2015.