Please answer reasonably -- What entities in a single stationary image of a B&W film's negative are measured in Hz?

[GreenXenon]

Hi:

What entities -- excluding wavelength of light [or any EM radiation
for that matter] -- in a single stationary image of the negative of a
B&W film are measured in Hz?

What will the image look like if I downshift the frequencies of those
entities to 0.1 Hz?

Hz is commonly used to measure cycles-per-constant-time [usually in
seconds] but could also be used to measure cycles-per-constant-
distance [as in the cycles-per-meter in spatial frequency]. Right?

If a single stationary image is low-pass-filtered it will look duller.
If it is high-pass-filtered it will look sharper. This is an example
of frequency-processing in which Hz is *not* the reciprocal of the
period with respect to time.

In this case Hz measures the reciprocal of the period with respect to
distance. Right?

What other than spatial frequency would be measured in Hz in my above
scenario?

No offense but please respond with reasonable answers & keep out the
jokes, off-topic nonsense, taunts, insults, and trivializations. I am
really interested in this.


Thanks

[Dan M]

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

[Steve Kraus]

Please don't encourage the troll.

[GreenXenon]

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

http://en.wikipedia.org/wiki/Spatial_frequency

"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

[Savageduck]

Post by GreenXenon

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

http://en.wikipedia.org/wiki/Spatial_frequency
"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

Are you in anyway related to Hughes/Eugene?
Your M/O is remarkably similar to his.
If not the two of you should be closeted away together, so you can
discuss arcane, stuff to your heart's content.

[Scott Dorsey]

Post by GreenXenon

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

http://en.wikipedia.org/wiki/Spatial_frequency
"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

Meters and seconds are not the same thing, no.
--scott

[Savageduck]

Post by Scott Dorsey

Post by GreenXenon

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

http://en.wikipedia.org/wiki/Spatial_frequency
"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

Meters and seconds are not the same thing, no.
--scott

It appears spatial frequency has nothing to do with light, sound, radio
wave, energy or any other physics use of "frequency."

It is the periodic positioning of any structure across a position in
space. Therefore the simplest example I can think of would be a picket
fence, where each picket is positioned periodically across a given
distance. Therefore if we can fit 5 pickets per meter, making that
result the SI unit of spatial frequency for this example.
In a cinematic sense this could relate to the number of frames per
meter on a reel of film stock vs. frames per second. The same would
apply to the number of sprocket holes on the film edges

I still don't think any response is going to satisfy GreenXenon.

Having said that in response to this tiresome thread, my head hurts!

[J. Clarke]

Post by Savageduck

In article

Post by GreenXenon

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with
respect to distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1
second of elapsed time, Hertz cannot be used to expressed the
measurement.

http://en.wikipedia.org/wiki/Spatial_frequency
"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

Meters and seconds are not the same thing, no.
--scott

It appears spatial frequency has nothing to do with light, sound, radio
wave, energy or any other physics use of "frequency."
It is the periodic positioning of any structure across a position in
space. Therefore the simplest example I can think of would be a picket
fence, where each picket is positioned periodically across a given
distance. Therefore if we can fit 5 pickets per meter, making that
result the SI unit of spatial frequency for this example.
In a cinematic sense this could relate to the number of frames per
meter on a reel of film stock vs. frames per second. The same would
apply to the number of sprocket holes on the film edges
I still don't think any response is going to satisfy GreenXenon.
Having said that in response to this tiresome thread, my head hurts!

With light, spatial frequencies occur in the context of interference
patterns.

[Sir None Of Your Business]

On Fri, 8 May 2009 19:12:49 -0400, "J. Clarke"

Post by J. Clarke
With light, spatial frequencies occur in the context of interference
patterns.

Don't feed the GreenTroll

noyb

[GreenXenon]

Post by Savageduck

Post by Scott Dorsey

Post by GreenXenon

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

http://en.wikipedia.org/wiki/Spatial_frequency
"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

Meters and seconds are not the same thing, no.
--scott

It appears spatial frequency has nothing to do with light, sound, radio
wave, energy or any other physics use of "frequency."
It is the periodic positioning of any structure across a position in
space. Therefore the simplest example I can think of would be a picket
fence, where each picket is positioned periodically across a given
distance. Therefore if we can fit 5 pickets per meter, making that
result the SI unit of spatial frequency for this example.
In a cinematic sense this could relate to the number of frames per
meter on a reel of film stock vs. frames per second. The same would
apply to the number of sprocket holes on the film edges
I still don't think any response is going to satisfy GreenXenon.
Having said that in response to this tiresome thread, my head hurts!
--
Regards,
Savageduck

Lets say there is a single stationary image black image with white
lines in it.

Higher spatial frequency = smaller lines, more lines in the image,
more lines per area in the image.

Lower spatial frequency = bigger lines, less lines in image, less
lines per area in image.

[GreenXenon]

Post by Savageduck

Post by Scott Dorsey

Post by GreenXenon

Post by Dan M

Post by GreenXenon
In this case Hz measures the reciprocal of the period with respect to
distance. Right?

"Hertz" is, by definition, "cycles per second". If the frequency of
recurrence is measured for a unit of comparison other than 1 second of
elapsed time, Hertz cannot be used to expressed the measurement.

http://en.wikipedia.org/wiki/Spatial_frequency
"In mathematics, physics, and engineering, spatial frequency is a
characteristic of any structure that is periodic across position in
space. The spatial frequency is a measure of how often the structure
repeats per unit of distance. The SI unit of spatial frequency is
cycles per meter."

Meters and seconds are not the same thing, no.
--scott

It appears spatial frequency has nothing to do with light, sound, radio
wave, energy or any other physics use of "frequency."
It is the periodic positioning of any structure across a position in
space. Therefore the simplest example I can think of would be a picket
fence, where each picket is positioned periodically across a given
distance. Therefore if we can fit 5 pickets per meter, making that
result the SI unit of spatial frequency for this example.
In a cinematic sense this could relate to the number of frames per
meter on a reel of film stock vs. frames per second. The same would
apply to the number of sprocket holes on the film edges
I still don't think any response is going to satisfy GreenXenon.
Having said that in response to this tiresome thread, my head hurts!
--
Regards,
Savageduck

Ok, lets say there is a single stationary image black image with white
lines in it.

Higher spatial frequency = smaller lines, more lines in the image,
more lines per area in the image.

Lower spatial frequency = bigger lines, less lines in image, less
lines per area in image.

[Sir None Of Your Business]

On Fri, 8 May 2009 15:46:45 -0700, Savageduck

Post by Savageduck
Having said that in response to this tiresome thread, my head hurts!

That's what you deserve for feeding the troll. I hope that headache
will last all weekend!

noyb

[Savageduck]

On 2009-05-08 22:26:20 -0700, Sir None Of Your Business

Post by Sir None Of Your Business
On Fri, 8 May 2009 15:46:45 -0700, Savageduck

Post by Savageduck
Having said that in response to this tiresome thread, my head hurts!

That's what you deserve for feeding the troll. I hope that headache
will last all weekend!
noyb

You wouldn't have any medication, ...or a wall to pound my head with handy?

[Doug Jewell]

Post by GreenXenon
What entities -- excluding wavelength of light [or any EM radiation
for that matter] -- in a single stationary image of the negative of a
B&W film are measured in Hz?
What will the image look like if I downshift the frequencies of those
entities to 0.1 Hz?
Hz is commonly used to measure cycles-per-constant-time [usually in
seconds] but could also be used to measure cycles-per-constant-
distance [as in the cycles-per-meter in spatial frequency]. Right?
If a single stationary image is low-pass-filtered it will look duller.
If it is high-pass-filtered it will look sharper. This is an example
of frequency-processing in which Hz is *not* the reciprocal of the
period with respect to time.
In this case Hz measures the reciprocal of the period with respect to
distance. Right?
What other than spatial frequency would be measured in Hz in my above
scenario?
No offense but please respond with reasonable answers & keep out the
jokes, off-topic nonsense, taunts, insults, and trivializations. I am
really interested in this.
Thanks

So if I'm understanding your question, which doesn't make a
lot of sense, you are asking what would happen if the
spatial frequency on the piece of film was .1 cycles/metre?
(which you are incorrectly calling .1 Hz).

Well assuming that is what you are asking, one cycle would
require 10m of film.

Assuming that the intensity of the image changed from Dmin
to Dmax over the course of the cycle, the intensity at any
point along the piece of film would be:
Da=(Dmax+Dmin)/2 + (Dmax-Dmin)(sin a)/2
Where a = the phase angle at that position
a (in degrees) = x (in mm) / 10,000mm * 360 deg.

The variation in brightness across the space of a 35mm film
would then be
dD=(Dmax-Dmin)((sin a)-(sin a+1.296))

The maximum variation would be at the points where the
waveform crosses the midpoint. At these points, in the space
of 36mm the density would vary by 2.2% of Dmax-Dmin.

Therefore for a "waveform" with a cycle of .1 cycles/metre,
the maximum variation across the space of a single frame of
35mm film is so small that it would be barely noticeable.

I hope this answers your question and you'll now STFU.

[Mr.T]

<Crap as usual>

Post by Doug Jewell
I hope this answers your question and you'll now STFU.

Vain hope I'm afraid.

MrT.