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For an online calculators:
(but please note that these
calculators require a JavaScript capable browser) |
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WAVELENGTH OF SOUND CALCULATOR |
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"This calculator will tell you the
wavelength of any airborne audio frequency in inches, feet and metres,
based on the speed of sound at sea level, and at 20 degrees Celsius or
72 degrees Fahrenheit. Note that with audio frequencies of 20Hz
to 20,000Hz the range of physical sizes of wavelengths is substantial
(1000:1), and this causes no end of problems with loudspeaker system
design." |
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CRITICAL DISTANCE CALCULATOR |
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"Critical distance is the
distance at which the reverberant sound field is equal in level
to the direct sound from a sound source. For reverb times
of less than 1.6 seconds, a listener could be up to 3.16 times
critical distance from a sound source. For reverb times
greater than 1.6 seconds, this multiplier gradually drops to a
value of 1. This becomes critical in sound system design
in reverberant spaces such as arenas. This calculation
provides critical distance values an unaided voice with a Q (or
directivity) of 2, and for a
single
loudspeaker with a selectable coverage pattern. Note that at
very long reverb times (5 seconds) the critical distance is very
short for unaided voice, and this affects speech communication." |
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Decibels and Distance
CALCULATOR
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"This calculation will give you
the amount of attenuation, in decibels, you can expect with a
change in receiver distance, in a free field (outdoors).
For example if you were standing 10 feet from a noise source,
and were to move 100 feet away from that noise source, you would
expect to see a drop in level of 20dB. Sound that is
radiated from a point source drops in level at 6dB per doubling
of distance. If you start at 50 feet from the source and
move to 100 feet from the source you will have a 6dB drop in
level. If you move from 500 feet to 1000 feet, you will have a
6dB drop in level. For the record, the formula to
calculate this level drop is: Decibels of Change=20xlog(distance
1/distance 2), and you can calculate it on any scientific
calculator." |
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The Speaker Q
Calculator |
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"This page will calculate the
approximate Q of a loudspeaker from the rated coverage angles.
To accurately calculate Q you really need to use a full 3D polar
plot to identify the coverage variations compared to a true
spherical coverage pattern.
"Note that
the theoretical Q or Directivity index of a loudspeaker is very
theoretical. Real live loudspeakers tend to vary
significantly from theory, and one manufacturer's 90x40
loudspeaker is not often the same as another's.
Loudspeakers also vary widely in directivity with frequency.
Where a speaker may actually have a Q of 12.8 at 2kHz, it is
likely that that the directivity value would drop to a Q of 4 at
500Hz, and as low as a Q of 1 at 125Hz. A thorough
acoustical and sound system design would include the prediction
of expected sound system behaviour across the entire audio
bandwidth, taking into consideration the variations in
loudspeaker coverage and variations in reverberation time.
This is where computer modelling is very handy." |
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Ohm's Law Calculators |
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with many thanks to
Copyleft Statement
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Copyright © 1999-2001 Michael Stutz.
Verbatim copying of this document is
permitted, in any medium |
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TEMPERATURE CALCULATOR |
Written by Nicholas Alston
©1996-2003 calculator.com All rights reserved
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TIME CALCULATOR |
Copyright ©1996, 1997, 1998 Ian
Fennell
©1996-2002 calculator.com All rights reserved
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Unit (Distance / Weight /
Volume) Converter |
Copyrights ©1996-2002 Jonathan
Weesner
©1996-2002 calculator.com All rights reserved
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our thanks to
©1996-2005 Athera Corporation all rights reserved |
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DICTIONARY OF UNITS, BY
CATEGORY
by Frank Tapson |
..
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Centre for Innovation in
Mathematics Teaching, University of Exeter
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© Frank
Tapson2002 |
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dB CALCULATOR |
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dBm / dBW CALCULATOR |
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Thanks to
© Copyright 1999-2001 Besser Associates. All
rights reserved |
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Alternatively, you could calculate it
yourself using:
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VOLTAGE DROP CALCULATOR |
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"This program calculates Voltage Drop on a cable ,
given the Electric Power of the consumption , or the line current.
(enter one value, the other will be automatically calculated).
Influence of temperature is taken in account.
" The program is quite accurate , especially for cables
up to 35mm2 , where inductance is negligible.
For cables larger than 35mm2 , voltage drop is calculated by taking in
account inductance of cable approximately.
" Please note that this calculation is quite accurate for voltages up to
1000V, with cables lying in the open air, but just an approximation
for greater voltages, or cables buried in the ground.
" You must also consider that the program does not take
in account special situations ." |
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With very many thanks to
© 2001 Monachos. All
rights reserved |
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This is a highly rated site with
lots of information.
Especially interesting is the |
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HISTORY OF MECHANICAL
CALCULATORS |
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Copyright © James Redin |
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| Online technical
cinematography calculators and tools, provided on
Panavision's website |
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FRAME AND FORMAT LIST |
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"This is a table of Common Format Dimensions for 35mm,
16mm and Video and Still photographic images." |
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DOF / FOV / AOV
IMAGE CALCULATOR |
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"This calculator is similar to the Depth of Field
Calculator but also displays Angle of View in degrees,
Field of View (subject Dimensions) at a given Distance." |
TABLE OF EQUIVALENT
FOCAL LENGTHS |
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"Enter any two Motion Picture, video, or photographic
formats and display a table of focal lengths converted
to the other format. Also displays Angle of View
in degrees." |
FILM FOOTAGE,
FRAME AND
RUNNING TIME CALCULATOR |
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"This calculator will
display the footage required, number of 1000ft or 400ft
rolls, the number of frames, and the running time for
any common film and speed." |
FILM
SPEEDS/SHUTTER ANGLES FOR 50HZ
POWER USING MAGNETIC BALLAST HMI's
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"Table of Film useable
film speeds when using HMIs that don't have square wave
electronic ballasts with a 50Hz power supply." |
FILM
SPEEDS/SHUTTER ANGLES FOR 60HZ
POWER USING MAGNETIC BALLAST HMI's |
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"Table of Film useable
film speeds when using HMIs that don't have square wave
electronic ballasts with a 60Hz power supply." |
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TABLE OF F-STOP FRACTIONS |
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"Ever been involved in
the f-stop debate? Ever wondered why half way
between f1 andf2 is f1.8 and not f1.5? Here is a
table of true stop values to the 1/4 stop calculated
directly from the square root of 2." |
TABLE OF
ILLUMINATION IN FOOTCANDLES
FOR 1/50 SEC EXPOSURE FOR
MOTION PICTURE FILM |
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"This table gives a
guide to the footcandles required to expose common
motion picture films at a range of T-stops." |
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LINEAR CONVERSION CALCULATOR |
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"This convenient
calculator converts common units used in cinematography
and photography, and will, if required output in feet
and inches to the nearest 1/4"." |
With many thanks to
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The Federal Communications Commission
provide the following calculators on their website: |
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HOW FAR IS IT?
DISTANCE CALCULATOR |
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indo.com ©
2005 All Rights Reserved |
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