Negative Film Came out Clear

(snip, I wrote)

>> "For both digital and film, you need to low-pass filter when viewing."

> Errr, no! I don't usually put an LPF over my eyes when looking at photographic prints.

> If you mean that some distance is needed when viewing prints or monitor images - true, but what counts is the amount of distance required to give the illusion of smooth tone. I don't think anyone could argue that 35mm film at 3200 ISO, or even at 400 ISO, looks smoother than its digitally-shot equivalent.

From sampling theory, you can sample above the Nyquist frequency an appropriately bandwidth limited source, and reconstruct it perfectly, with appropriately bandwidth limited reconstruction filters.

And yes, in many cases, digital and AgBr, the low-pass filter is the limits of the optical system, including our eyes.

We live in a quantum universe, where many physical quantities can only have a finite number of values.

We consider the incoming light as analog, though it is quantized into photons. The CCD array outputs an integer number of electrons to the A/D converter.

Analog magnetic (audio and video) tape magnetizes ferric oxide grains either one way or the other, on the average with a magnetic field approximating the desired value. (The finite grain structure causes noise at higher frequencies, which is normally filtered out. It is also the cause for all the noise reduction systems in use for analog recording.)

Analog vinyl disks are made of atoms, which only approximate the desired continuous signal.

All these analog systems store quantized values. Unlike digital systems, though, the allowed values are continuously distributed, or at least as close to continuously as the universe allows.

My all-time favorite quantization problem, is how many different velocities a baseball pitcher and pitch at in a baseball stadium.

It is a function of the maximum speed, size of the stadium, and mass of the ball. (and is a very large, but not infinite, number)

https://www.ilfordphoto.com/amfile/file/download/file_id/1872/product_id/682/

iinteresting, no MTF curves for Delta 3200. They don't want you to know!

http://wwwca.kodak.com/global/en/professional/support/techPubs/f32/f002_0516ac.gif

Kodak gives the TMZ curve out to about 140 cycles/mm