7 ms·

> Of course they look better. Why?

by derleth 14y ago

delinka 14y ago
Because film captures details in molecules while a CCD sensor in your digital camera uses picture elements much, much, much larger than molecules. Or, because it's analog. It's very similar to sound recordings. Whether magnetic or not (say, in vinyl) the resolution of the captured signal can approach the molecular. Digital has a discreet resolution limited by the capturing equipment; for example, CDs reproduce the volume in a sound recording only 44,100 times per second. But a magnetic tape has a resolution limited only by the number of molecules passing the recording head every second (the more [i.e. the faster the tape], the better.)
- artursapek 14y ago
  Exactly
- parallel 14y ago
  The spacial resolution of analog photographs is not at the scale of individual molecules. It is limited by the "grain" of the film [1]. Other factors include distortions from lens shape imperfections in the lens material. Audio tapes record their signal in magnetic domains. These are areas of tape the are large enough to be written and read. Much larger than anything approaching the scale of individual molecules. Sound recordings on vinly are similarly limited by other factors. To "read" the signal from a record groove a needle is dragged a needle through a v shaped groove. This needle jiggles up and down and left and right, hence the two channels in stereo. The time resolution of the signal (max frequency) is limited by the physics of the jiggling head. It's inertia prevents it from reading signals over a certain limiting frequency. Again, well before the molecular level. [1] http://en.wikipedia.org/wiki/Film_grain http://en.wikipedia.org/wiki/Film_grain [edit] - Changed momentum to inertia in the last paragraph.
  - delinka 14y ago
    I figured my layman explanation would suffice. While we're in the realm of correct details, it's also worth nothing that with each use of a needle dragged through a groove (or even with magnetic tape dragging across all the bits in the tape machine) the surface is degraded and the original recording along with it. Less fidelity, more noise ... hiss, pop, crack Digital gives us error correction so that even when the physical media starts to degrade (taking the signal with it) our firmware and our software work out where the mistakes exist and attempt to correct them. Of course, once the signal has degraded beyond the point of recoverability, you "suddenly" have a catastrophic failure. (And this is why backups are important...)
  - mistercow 14y ago
    A couple points to add to that: with vinyl, the recording process itself (for which there are several techniques) also adds noise. The recording head (in whatever form) is also subject to physical laws. The materials used at each stage of the process are also not ideal substrates. Hell, vinyl is a polymer, which means it's a big tangle of chained molecules. Even if everything else were perfect, it would not be possible to write data at a molecular scale into such a medium.
- sukuriant 14y ago
  We're actually approaching, if not have passed, the resolution of standard film with some higher end SLRs [1, 2]; at least in a total-usable-pixels perspective; but of course at the sub-pixel level, we're still very far off with only 14 bits per channel. There's also the question of how the total pixels are arranged, since each bit of the sensor is only absorbing one color, etc; but in time, at least as far as resolution is concerned, digital will or has surpassed analogue. [1] http://www.mindspring.com/~lorqvonray/Sticker-5mp-Velvia.html http://www.mindspring.com/~lorqvonray/Sticker-5mp-Velvia.htm... [2] http://www.clarkvision.com/imagedetail/film.vs.digital.summary1.html http://www.clarkvision.com/imagedetail/film.vs.digital.summa... Some ludicrous camera resolutions. Please not I'm trying to bring up cameras that are full-frame and have ludicrous sensor resolutions, so the arguments of "light doesn't work right at these densities" doesn't fly as easily, since the density is still relatively low: http://imaging.nikon.com/lineup/dslr/d800/ http://imaging.nikon.com/lineup/dslr/d800/ http://www.usa.canon.com/cusa/consumer/products/cameras/slr_cameras/eos_5d_mark_iii http://www.usa.canon.com/cusa/consumer/products/cameras/slr_...
  - sjwright 14y ago
    Ask any working professional photographer and they'll tell you we passed the practical resolution of film (35mm vs 35mm) years ago, and with the insanely low noise levels, we passed the dynamic range potential years ago too. With the latest cameras in hand, you can capture sharper and cleaner photographs than the best 35mm film could ever manage, and you can do it with a tiny fraction of the light (1/16th the amount, or 4 stops, or 100 ISO film < 1600 ISO digital). What you're seeing with the latest crop of pro cameras are 35mm sensors that are competitive with the best medium format film.
    - sukuriant 14y ago
      I probably mostly hear from purists and those people that don't want to look at the facts because "records are better than CD's" and similar arguments. I didn't know they were competing with medium format film now. That's .. saying something. o.o
      - 14y ago
- sjwright 14y ago
  You say "only 44,100 times per second" as if it were somehow deficient. It's not, assuming the purpose of the sampling is to be heard by a human ear. In fact, you'd be hard-pressed to make a legitimate, evidence-based argument justifying a significantly higher rate, for consumer music distribution purposes. http://drewdaniels.com/audible.pdf http://drewdaniels.com/audible.pdf
- kalleboo 14y ago
  If film captures details at a molecular level, why are my old 400 ASA APS snaps so much grainier and lower-detailed than my cell phone snaps?
- derleth 14y ago
  > CDs reproduce the volume in a sound recording only 44,100 times per second. Because humans can't hear sounds higher than 22 kHz, so with a 44.1 kHz sampling rate you're guaranteed to capture everything humans can hear. Besides, tape has wow and flutter and records invariably have scratches and dust, not to mention limits in dynamic range. http://rationalwiki.org/wiki/Audio_woo http://rationalwiki.org/wiki/Audio_woo
  - kwekly 14y ago
    The analogous concept here is the product of sampling rate and bit-depth, the number of bits per sample i.e the precision of the recording
- anovikov 14y ago
  This is nonsense, analog also has a resolution. The stated resolution for the best audio cassettes i seen were 70us, correspondent (according to Niquist formula) to 28kHz digitalization, 1.5 worse than CDs. Most were worse, and it was just the resolution of the tape itself, telling nothing about ability of the recorder head to write them or read. Same goes to photo film: image consists not of molecules, but of silver granules on film which are about a micron size, and either black or white. Actual resolution (which depends on contrast) is indicated on a film roll (for quality films), as a chart lp/mm vs contrast. While high resolution (and low-sensitive) film beats CCDs in this regard, reaching and somewhat exceeding 100 lp/mm which is equivalent to 2.5 microns per pixel, remember about Bayer pattern on chips to make color photos, vs about 5 microns per pixel in CCDs on DSLRs, this only comes with low sensitivity and other issues. General purpose photo films in most common shooting conditions are normally about same resolution as a good DSLR (full-frame because otherwise you have to apply a crop factor), and even than is an overshoot because most lenses does not provide that resolution, see MTF chart for most of them, the 'resolution' line is typically drawn measured at 30 lp/mm equivalent! I am not even talking about such a fundamental effect as diffraction. It will block any further increase in image quality, whatever the lens and film is, long before you get down to 'molecules' (in fact, diffraction is in fact a limiting factor for resolution in many shooting conditions). How important is the diffraction? Let's take practical best and worst case. Best case: Full frame 20mpix DSLR, 6.5u pixels. Canon EF 50mm F/1.2L fixed focal length lens, resulting in about 41.6mm aperture. Resolution at peak sensitivity of 0.55 microns for this lens means that diffraction disk diameter will be 1.22 * 0.55/41666=1.61E-05 rad, which will be seen from 50mm distance (focal length, i.e. distance to film) as having 0.8u diameter - 8 times less than the pixel. So diffraction has no meaning here. But, it is easy to see that there is a direct relationship between focal ratio and Airy disk diameter, so when diaphragm closes to 1.2*6.5/0.8 = ~f/9.7, Airy disk becomes as big as the pixel - making smaller pixel useless. This is not an extreme value - doing outdoor shooting in all-auto mode normally results in images done at f/8 or f/11 diaphragm. So, making pixels much smaller than they are now is all but useless even in a perfect optical system (which does not exist). Of course, same equally applies to film.
URSpider94 14y ago
Three reasons that I can think of: 1. These images are likely captured on large-format glass plates, not tiny sensors. Therefore, the amount of magnification required is much less (these may be nearly 1:1 on a standard laptop display). 2. Chemical emulsions typically have much more dynamic range than digital sensors, allowing for more highlight and shadow detail. 3. Capturing colors in three separate exposures gets rid of the need for de-mosaicing.
michrassena 14y ago
Part of the reason is because the glass plates the images were photographed on are relatively large. The glass plate was 3inches by 9inches, meaning each image was approximately 3x3. This is somewhat larger (about 80% more area 9 sq in vs 5 sq in) than medium format film and about 8 times the size of 35mm film. While it's generally accepted that 35mm is "dead", it's still being debated whether digital has surpassed medium format. Take a look at shorpy http://www.shorpy.com/ http://www.shorpy.com/ sometime. They have medium-res scans of full glass plates (8x10, 80 sq inches) and you can see the level of detail that a large negative captures. A full scan of the plate, capturing every transition between dark and light (line pair) would surely be in the hundreds of megapixels. In fact you can see that many of these images are limited not by the resolution of the plate, but the lens technology (the corners of the images are often blurred, and lens imperfection called coma)

> Of course they look better. Why?

by derleth 14y ago

> Of course they look better. Why?

Because film captures details in molecules while a CCD sensor in your digital camera uses picture elements much, much, much larger than molecules. Or, because it's analog. It's very similar to sound recordings. Whether magnetic or not (say, in vinyl) the resolution of the captured signal can approach the molecular. Digital has a discreet resolution limited by the capturing equipment; for example, CDs reproduce the volume in a sound recording only 44,100 times per second. But a magnetic tape has a resolution limited only by the number of molecules passing the recording head every second (the more [i.e. the faster the tape], the better.)

artursapek 14y ago
Exactly
parallel 14y ago
The spacial resolution of analog photographs is not at the scale of individual molecules. It is limited by the "grain" of the film [1]. Other factors include distortions from lens shape imperfections in the lens material. Audio tapes record their signal in magnetic domains. These are areas of tape the are large enough to be written and read. Much larger than anything approaching the scale of individual molecules. Sound recordings on vinly are similarly limited by other factors. To "read" the signal from a record groove a needle is dragged a needle through a v shaped groove. This needle jiggles up and down and left and right, hence the two channels in stereo. The time resolution of the signal (max frequency) is limited by the physics of the jiggling head. It's inertia prevents it from reading signals over a certain limiting frequency. Again, well before the molecular level. [1] http://en.wikipedia.org/wiki/Film_grain http://en.wikipedia.org/wiki/Film_grain [edit] - Changed momentum to inertia in the last paragraph.
- delinka 14y ago
  I figured my layman explanation would suffice. While we're in the realm of correct details, it's also worth nothing that with each use of a needle dragged through a groove (or even with magnetic tape dragging across all the bits in the tape machine) the surface is degraded and the original recording along with it. Less fidelity, more noise ... hiss, pop, crack Digital gives us error correction so that even when the physical media starts to degrade (taking the signal with it) our firmware and our software work out where the mistakes exist and attempt to correct them. Of course, once the signal has degraded beyond the point of recoverability, you "suddenly" have a catastrophic failure. (And this is why backups are important...)
- mistercow 14y ago
  A couple points to add to that: with vinyl, the recording process itself (for which there are several techniques) also adds noise. The recording head (in whatever form) is also subject to physical laws. The materials used at each stage of the process are also not ideal substrates. Hell, vinyl is a polymer, which means it's a big tangle of chained molecules. Even if everything else were perfect, it would not be possible to write data at a molecular scale into such a medium.
sukuriant 14y ago
We're actually approaching, if not have passed, the resolution of standard film with some higher end SLRs [1, 2]; at least in a total-usable-pixels perspective; but of course at the sub-pixel level, we're still very far off with only 14 bits per channel. There's also the question of how the total pixels are arranged, since each bit of the sensor is only absorbing one color, etc; but in time, at least as far as resolution is concerned, digital will or has surpassed analogue. [1] http://www.mindspring.com/~lorqvonray/Sticker-5mp-Velvia.html http://www.mindspring.com/~lorqvonray/Sticker-5mp-Velvia.htm... [2] http://www.clarkvision.com/imagedetail/film.vs.digital.summary1.html http://www.clarkvision.com/imagedetail/film.vs.digital.summa... Some ludicrous camera resolutions. Please not I'm trying to bring up cameras that are full-frame and have ludicrous sensor resolutions, so the arguments of "light doesn't work right at these densities" doesn't fly as easily, since the density is still relatively low: http://imaging.nikon.com/lineup/dslr/d800/ http://imaging.nikon.com/lineup/dslr/d800/ http://www.usa.canon.com/cusa/consumer/products/cameras/slr_cameras/eos_5d_mark_iii http://www.usa.canon.com/cusa/consumer/products/cameras/slr_...
- sjwright 14y ago
  Ask any working professional photographer and they'll tell you we passed the practical resolution of film (35mm vs 35mm) years ago, and with the insanely low noise levels, we passed the dynamic range potential years ago too. With the latest cameras in hand, you can capture sharper and cleaner photographs than the best 35mm film could ever manage, and you can do it with a tiny fraction of the light (1/16th the amount, or 4 stops, or 100 ISO film < 1600 ISO digital). What you're seeing with the latest crop of pro cameras are 35mm sensors that are competitive with the best medium format film.
  - sukuriant 14y ago
    I probably mostly hear from purists and those people that don't want to look at the facts because "records are better than CD's" and similar arguments. I didn't know they were competing with medium format film now. That's .. saying something. o.o
    - 14y ago
sjwright 14y ago
You say "only 44,100 times per second" as if it were somehow deficient. It's not, assuming the purpose of the sampling is to be heard by a human ear. In fact, you'd be hard-pressed to make a legitimate, evidence-based argument justifying a significantly higher rate, for consumer music distribution purposes. http://drewdaniels.com/audible.pdf http://drewdaniels.com/audible.pdf
kalleboo 14y ago
If film captures details at a molecular level, why are my old 400 ASA APS snaps so much grainier and lower-detailed than my cell phone snaps?
derleth 14y ago
> CDs reproduce the volume in a sound recording only 44,100 times per second. Because humans can't hear sounds higher than 22 kHz, so with a 44.1 kHz sampling rate you're guaranteed to capture everything humans can hear. Besides, tape has wow and flutter and records invariably have scratches and dust, not to mention limits in dynamic range. http://rationalwiki.org/wiki/Audio_woo http://rationalwiki.org/wiki/Audio_woo
- kwekly 14y ago
  The analogous concept here is the product of sampling rate and bit-depth, the number of bits per sample i.e the precision of the recording
anovikov 14y ago
This is nonsense, analog also has a resolution. The stated resolution for the best audio cassettes i seen were 70us, correspondent (according to Niquist formula) to 28kHz digitalization, 1.5 worse than CDs. Most were worse, and it was just the resolution of the tape itself, telling nothing about ability of the recorder head to write them or read. Same goes to photo film: image consists not of molecules, but of silver granules on film which are about a micron size, and either black or white. Actual resolution (which depends on contrast) is indicated on a film roll (for quality films), as a chart lp/mm vs contrast. While high resolution (and low-sensitive) film beats CCDs in this regard, reaching and somewhat exceeding 100 lp/mm which is equivalent to 2.5 microns per pixel, remember about Bayer pattern on chips to make color photos, vs about 5 microns per pixel in CCDs on DSLRs, this only comes with low sensitivity and other issues. General purpose photo films in most common shooting conditions are normally about same resolution as a good DSLR (full-frame because otherwise you have to apply a crop factor), and even than is an overshoot because most lenses does not provide that resolution, see MTF chart for most of them, the 'resolution' line is typically drawn measured at 30 lp/mm equivalent! I am not even talking about such a fundamental effect as diffraction. It will block any further increase in image quality, whatever the lens and film is, long before you get down to 'molecules' (in fact, diffraction is in fact a limiting factor for resolution in many shooting conditions). How important is the diffraction? Let's take practical best and worst case. Best case: Full frame 20mpix DSLR, 6.5u pixels. Canon EF 50mm F/1.2L fixed focal length lens, resulting in about 41.6mm aperture. Resolution at peak sensitivity of 0.55 microns for this lens means that diffraction disk diameter will be 1.22 * 0.55/41666=1.61E-05 rad, which will be seen from 50mm distance (focal length, i.e. distance to film) as having 0.8u diameter - 8 times less than the pixel. So diffraction has no meaning here. But, it is easy to see that there is a direct relationship between focal ratio and Airy disk diameter, so when diaphragm closes to 1.2*6.5/0.8 = ~f/9.7, Airy disk becomes as big as the pixel - making smaller pixel useless. This is not an extreme value - doing outdoor shooting in all-auto mode normally results in images done at f/8 or f/11 diaphragm. So, making pixels much smaller than they are now is all but useless even in a perfect optical system (which does not exist). Of course, same equally applies to film.

URSpider94 14y ago

Three reasons that I can think of: 1. These images are likely captured on large-format glass plates, not tiny sensors. Therefore, the amount of magnification required is much less (these may be nearly 1:1 on a standard laptop display). 2. Chemical emulsions typically have much more dynamic range than digital sensors, allowing for more highlight and shadow detail. 3. Capturing colors in three separate exposures gets rid of the need for de-mosaicing.

michrassena 14y ago

Part of the reason is because the glass plates the images were photographed on are relatively large. The glass plate was 3inches by 9inches, meaning each image was approximately 3x3. This is somewhat larger (about 80% more area 9 sq in vs 5 sq in) than medium format film and about 8 times the size of 35mm film. While it's generally accepted that 35mm is "dead", it's still being debated whether digital has surpassed medium format. Take a look at shorpy http://www.shorpy.com/ http://www.shorpy.com/ sometime. They have medium-res scans of full glass plates (8x10, 80 sq inches) and you can see the level of detail that a large negative captures. A full scan of the plate, capturing every transition between dark and light (line pair) would surely be in the hundreds of megapixels. In fact you can see that many of these images are limited not by the resolution of the plate, but the lens technology (the corners of the images are often blurred, and lens imperfection called coma)