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Something that I have wondered about is the photo quality of film photo enlargements vs. digital (which I guess is just zooming). A film is continuous right, s

Something that I have wondered about is the photo quality of film photo enlargements vs. digital (which I guess is just zooming). A film is continuous right, so no amount of digital encoding would truly encode a strip of film. Of course there is a point after which it doesn't matter, but I am more interested in the technical look and feel of film vs. digital. A few years ago I looked at a film enlargement to A4 in a scrapbook and I have to say it had a different feeling about it. There were also funny artifacts of the kind that make superstitious people believe in invisible spheres that ehm are not invisible on film...? If you contrast this with a CD recording, the bit rate is limited even if it's an audio CD due to the way they were recorded. Vinyl is supposed to be limited to 48 bits, but perhaps you can engrave in an analog way?

matthewmcg 6y ago
Film is certainly not continuous—its spatial resolution is limited by the size of the individual light sensitive crystals that capture the image. These appear as the grain structure in enlargements.
- mikorym 6y ago
  Does this hold for all types of film? For example, how small can the grain structure be?
  - AuryGlenz 6y ago
    It can be quite small, but I believe it largely depends on the ISO rating of the film. Larger grain = more light collected. I shoot wetplate collodion sometimes and that has an effective ISO of under 2 and the detail is astounding - especially for a process that’s 150 years old.
  - matthewmcg 6y ago
    Interesting question! Actually all photographic imaging systems run into physical limits set by the quantized nature of light. So even if you could shrink things down to one molecule, you’d have other problems first, principally an effect called “shot noise.” Essentially, a film grain or a cell on a CCD sensor is like a “bin” that collects and counts photons. As you make the area of the bins smaller, there are fewer photons collected in a given image, and statistical fluctuations from sampling become more relevant. You get more “noise” in the final image. See https://en.wikipedia.org/wiki/Shot_noise https://en.wikipedia.org/wiki/Shot_noise
    - neltnerb 6y ago
      With the exception that holographic film images the diffraction pattern produced by two interfering laser beams, so typical grain size there has to be on the order of tens of nanometers. It can certainly be done, just is pointless for normal film =)
    - mikorym 6y ago
      Those physical limits are surely though at a much finer resolution that common high end digital cameras? I understand that you are saying that you see the effects even if you are not a the "molecule" level as you say, but I would think that the hard theoretic limit of photons should be at a finer granularity than high end digital cameras.
TheOtherHobbes 6y ago
Vinyl is limited to around 12 bits. It has a dynamic range of around 70dB. Vinyl sounds "nice" because recording and playback add distortion and noise at the low end, which gives bass and drums more weight, while the top end is smooth and extends higher than CD - which sounds like "air" because any intermodulation distortion in the amp and speakers will fold it back to audibility, even though nominally it's ultrasonic. Chemical film creates distortions of its own. Colour film often pushes the reds to make skin tones, lipstick, and sunsets warmer. You can choose how much grain you want and B&W is often shot on fast high-grain film to give it a gritty textured look. Landscapes need slow micro-grain film to look as lush and detailed as possible. And so on. The point is chemical film isn't any more real than a digital CCD. Digital consumer displays all have colour distortions and dynamic range limitations, and so does chemical processing. Even if you apply no deliberate processing to an image, by the time it ends up on paper or a web page it usually looks quite different to the scene you'd see with your eyes. So yes - the "feel" is different. And that's a creative choice - or it can be, for the professionals. Polaroids look very different to medium format. Amateur phonecam users get one-size-fits-all enhancement whether they want it or not, in addition to some basic editing options. If they didn't their lifestyle shots on IG would all look lacklustre, and they wouldn't be happy about that.
- mikorym 6y ago
  Assuming that you have the technical ability, how many pixels do you need at how many colours to completely simulate film? I think that should refine my question.
  - AuryGlenz 6y ago
    Your common high end DSLR definitely outresolves 35mm film nowadays, especially at higher ISOs. It’s not a 1:1 comparison, but film does have grain and that grain size is the “limit” of the data. That said medium format film and larger would still be hard to beat. As far as tonality, a modern sensor should also have greater dynamic range than almost all film. They do behave differently though - highlights are harder to overexposed on film but dark areas are easier to underexpose, compared to digital.

matthewmcg 6y ago

Film is certainly not continuous—its spatial resolution is limited by the size of the individual light sensitive crystals that capture the image. These appear as the grain structure in enlargements.

mikorym 6y ago
Does this hold for all types of film? For example, how small can the grain structure be?
- AuryGlenz 6y ago
  It can be quite small, but I believe it largely depends on the ISO rating of the film. Larger grain = more light collected. I shoot wetplate collodion sometimes and that has an effective ISO of under 2 and the detail is astounding - especially for a process that’s 150 years old.
- matthewmcg 6y ago
  Interesting question! Actually all photographic imaging systems run into physical limits set by the quantized nature of light. So even if you could shrink things down to one molecule, you’d have other problems first, principally an effect called “shot noise.” Essentially, a film grain or a cell on a CCD sensor is like a “bin” that collects and counts photons. As you make the area of the bins smaller, there are fewer photons collected in a given image, and statistical fluctuations from sampling become more relevant. You get more “noise” in the final image. See https://en.wikipedia.org/wiki/Shot_noise https://en.wikipedia.org/wiki/Shot_noise
  - neltnerb 6y ago
    With the exception that holographic film images the diffraction pattern produced by two interfering laser beams, so typical grain size there has to be on the order of tens of nanometers. It can certainly be done, just is pointless for normal film =)
  - mikorym 6y ago
    Those physical limits are surely though at a much finer resolution that common high end digital cameras? I understand that you are saying that you see the effects even if you are not a the "molecule" level as you say, but I would think that the hard theoretic limit of photons should be at a finer granularity than high end digital cameras.

TheOtherHobbes 6y ago

Vinyl is limited to around 12 bits. It has a dynamic range of around 70dB. Vinyl sounds "nice" because recording and playback add distortion and noise at the low end, which gives bass and drums more weight, while the top end is smooth and extends higher than CD - which sounds like "air" because any intermodulation distortion in the amp and speakers will fold it back to audibility, even though nominally it's ultrasonic. Chemical film creates distortions of its own. Colour film often pushes the reds to make skin tones, lipstick, and sunsets warmer. You can choose how much grain you want and B&W is often shot on fast high-grain film to give it a gritty textured look. Landscapes need slow micro-grain film to look as lush and detailed as possible. And so on. The point is chemical film isn't any more real than a digital CCD. Digital consumer displays all have colour distortions and dynamic range limitations, and so does chemical processing. Even if you apply no deliberate processing to an image, by the time it ends up on paper or a web page it usually looks quite different to the scene you'd see with your eyes. So yes - the "feel" is different. And that's a creative choice - or it can be, for the professionals. Polaroids look very different to medium format. Amateur phonecam users get one-size-fits-all enhancement whether they want it or not, in addition to some basic editing options. If they didn't their lifestyle shots on IG would all look lacklustre, and they wouldn't be happy about that.

mikorym 6y ago
Assuming that you have the technical ability, how many pixels do you need at how many colours to completely simulate film? I think that should refine my question.
- AuryGlenz 6y ago
  Your common high end DSLR definitely outresolves 35mm film nowadays, especially at higher ISOs. It’s not a 1:1 comparison, but film does have grain and that grain size is the “limit” of the data. That said medium format film and larger would still be hard to beat. As far as tonality, a modern sensor should also have greater dynamic range than almost all film. They do behave differently though - highlights are harder to overexposed on film but dark areas are easier to underexpose, compared to digital.