I saw a troupe of six fingered gnomes playing dodge-ball with a Fabergé egg in my garden this morning. They said something about being the point spread function of a moonbeam.Originally Posted by rvhalejr
I saw a troupe of six fingered gnomes playing dodge-ball with a Fabergé egg in my garden this morning. They said something about being the point spread function of a moonbeam.
> Originally Posted by rvhalejr View Post
> One more thing (I'm agnostic about film and digital, both having strong and
> weak points), I've seen a transparency that had no grain (way above 3200dpi)
> and a digital image that exceeded the nyquist frequency[1] limit by a factor of 2.
So they were qualified radiometry experts discussing moon beam scatter and spectral emission line shift
One out of 10,000 slides, its the holidays ok?
I've never seen a transparency (before or since) that would benefit from a
greater than 5000 ppi fluid scan, except for that one. It was old ISO 25
E6 Kodak film (legendary noise floor 1/2 that of ISO 50).
Maybe Nyquist sampling of sequential data got those gnomes (they might
have been department chairs at prestigious institutions).
If the data context is from an image, (not just a simple string of
bits) the matrix will have a huge amount of information that (in theory) can
be exploited to build a 3d model, effectively appearing to be subpixel (or emulsion
cloud) sampling, as an admittedly overly simplistic analogy, hence the
"factor of 2" comment.
Those gnomes do need to allow for the possibility (how ever remote) that
1 out of 10,000 sub N frequency sampled photos will not exhibit aliasing due
to some factor not often encountered or observed.
Is this worthy of publication and peer review ? No. Will there never be a
generally accepted dissertation on MTF and how it might be cracked,
like an egg ?
That thesis was originally outlined by 10,000 monkeys in a room jumping
up and down on keyboards.
------------------
I wanted to edit that post but then ran into the 120 minute time out (after the
wife started screaming in one ear "GO GET MORE RIBBIONS AND BOWS !!!").
High five on the very entertaining reply!> Originally Posted by rvhalejr View Post
> One more thing (I'm agnostic about film and digital, both having strong and
> weak points), I've seen a transparency that had no grain (way above 3200dpi)
> and a digital image that exceeded the nyquist frequency[1] limit by a factor of 2.
So they were qualified radiometry experts discussing moon beam scatter and spectral emission line shift
One out of 10,000 slides, its the holidays ok?
I've never seen a transparency (before or since) that would benefit from a
greater than 5000 ppi fluid scan, except for that one. It was old ISO 25
E6 Kodak film (legendary noise floor 1/2 that of ISO 50).
Maybe Nyquist sampling of sequential data got those gnomes (they might
have been department chairs at prestigious institutions).
If the data context is from an image, (not just a simple string of
bits) the matrix will have a huge amount of information that (in theory) can
be exploited to build a 3d model, effectively appearing to be subpixel (or emulsion
cloud) sampling, as an admittedly overly simplistic analogy, hence the
"factor of 2" comment.
Those gnomes do need to allow for the possibility (how ever remote) that
1 out of 10,000 sub N frequency sampled photos will not exhibit aliasing due
to some factor not often encountered or observed.
Is this worthy of publication and peer review ? No. Will there never be a
generally accepted dissertation on MTF and how it might be cracked,
like an egg ?
That thesis was originally outlined by 10,000 monkeys in a room jumping
up and down on keyboards.
------------------
I wanted to edit that post but then ran into the 120 minute time out (after the
wife started screaming in one ear "GO GET MORE RIBBIONS AND BOWS !!!").
RAP100F holds a bit of detail above 2500cpi and so could benefit slightly from sampling a bit beyond 5000ppi but of course this would be with contrast that is far less than inspiring and of probably of marginal utility (not to mention beyond my ability to pull off in the real world). If there was truly a film in the distant past that exceeded this I would enjoy hearing more about it.
There is no unfiltered sub N frequency image that will be immune to aliasing in the real world. You can theoretically model what would be required but it won't look like anything we commonly think of as a photograph. However, this is the irony of the situation, if there is no aliasing there is also no contribution of higher frequencies in the sample to the frequency content which is resolved and if there is aliasing the contributed information is absolutely ambiguous. Also, if a given sample doesn't have sufficient information to represent subpixel frequencies in 2D how on earth do you presume it has enough to build a 3D model with perhaps orders of magnitude more degrees of freedom?
If you can do this it would be more than worthy of peer reviewed publication because it would be absolutely astounding to see a method that allows resolution beyond the folding frequency of the sampling system without some variation of oversampling (and statistical oversampling can be ruled out because we're only talking about one image) in which case the 'assumed' Nyquist frequency really isn't.
I humbly submit that you are correct.
Spectral Transmission and CIE Chromaticity (from rosco.com/us/filters/roscolux.asp)
suggest two gels worthy of consideration in this threads context:
#06 No Color Straw (ideal suppression curve for blue tint in white)
#3317 Tough 1/8 Plusgreen (partial green to balance with fluorescents)
When beloved photographers become concerned about the ghastly glow
of wide spectrum filtered and diffused florescent lighting one can say
"Its Moonlight" and perhaps let out a little wolf howl at an imaginary full moon.
During the pursuit of a disciplines advancement conventional wisdom,
canonical facts and empirical truths might be considered temporary final
approximations in the moment.
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