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According to this video, NASA still operates some cameras for tracking rocket launches that use film:

According to NASA, they even have some film cameras placed around their launch site loaded with over 1000 feet of film each

Why is that? It seems like the rest of their cameras are already digital, so why do they still use film cameras here?

David says Reinstate Monica
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    They may use cameras bought decades ago but still doing their job. The special telephoto lenses were expensive but not easily adapted to a new digital sensor. – Uwe Feb 13 '18 at 13:19
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    Digital imaging didn't surpass film until around 2005, between 2004 and 2008 Olympics. In 2004 journalists saw the clear speed advantage in terms of image development, processing, and transmission but didn't fully recognize the performance advantage(sensitivity, resolution, speed, etc) until the next. It took another a few years for digital to take over full speed and high speed video. – user3528438 Feb 13 '18 at 14:45
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    Also you should take a look at the size of the cameras. I guess they are the bigger ones. Strange as it sounds, digital imaging doesn't scale up as well as film. Film doesn't have as good of resolution density but it's easy to make very large films. In the past a lot of systems are designed to accommodate a large and low density sensor/film and it's simply prohibitively expensive to upgrade them to a equal-size digital sensor (10+ inch wide, 3 giga pixel?). – user3528438 Feb 13 '18 at 14:58
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    Also -- better is the enemy of good. If you have film cameras that you've been using, and they do the job well enough, what is the reason to switch to digital? – Tristan Feb 13 '18 at 15:03
  • If 35 mm film was uses with an image size of 18 * 24 mm and a resolution of 30 lines per mm, HDTV cameras were needed to get a similar resolution. About 1080 * 1440 pixel, one line on film is equivalent to two pixels. If something goes wrong during launch of the rocket, the films might help to identify the problem. No problem to wait a day or two for film development. – Uwe Feb 13 '18 at 15:48
  • Is that Youtube video accurate? – Hobbes Feb 13 '18 at 18:11
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    I looked around, and the film cameras used for Space Shuttle launches included a bunch of 16 mm cameras, a few 35 mm cameras, and at least one 70 mm camera. IMAX film is rated around 12k lines of resolution, 35 mm around 4k, and 16 mm around 2k. (IMAX 65 mm film is about twice as wide as 35 mm, but has a taller aspect ratio.) That's a lot of resolution, they already own the cameras, and launches are infrequent enough that film stock isn't a major expense. – Steve Feb 14 '18 at 05:56
  • Another factor--damage resistance. Suppose you are photographing something bright enough it could damage the recording media. Shoot film and you have a bit of melting, the rest of the shots are fine. Shoot digital and you have a burned sensor, you have damage to every shot after that point. Pointing your film camera at the sun isn't going to be an issue, pointing your DSLR at it might be. – Loren Pechtel Mar 06 '18 at 04:48
  • At least some of the cameras are high-speed. The combination of high-res (35/70 mm equivalent) and high-speed hasn't been available for that long yet. – Hobbes Jan 01 '19 at 14:38
  • Great video about the various filming and amazing shots! https://youtu.be/BlPfHV36G-g – user2705196 Jan 08 '19 at 15:47

2 Answers2

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I'm a little late to the game here but basically there are several reasons NASA continued to use film. One is reliability. While digital equipment and processing have made huge strides in the reliability department it is still not quite there yet. Apart from actually having the film physically tear or break in camera there isn't much that can go wrong to render it unusable. Secondly, modern film has very good dynamic range. The video captured can have a wide latitude in light levels and maintain ability to capture a usable image. NASA keeps launch footage archived for a number of reasons. The obvious one, monitoring for debris strikes goes without saying. Digital is used for getting a quick view of launch while the film is processed and digitized to video output. The movie industry has been doing this for eons. Film has an established track record. It's performance is known and understood, that leads to reliability and not missing critical shots. Also there is no use in change for the sake of change, especially when the current recording medium meets program requirements. I have a few photos from the Challenger disaster that were given to me by an engineer that worked at JSC in Houston. They were made from one of the 35mm films. They show the moments that the SRB started to burn through the external tank to when the lower mount failed. The quality is as good today as modern digital video is. Film has also advanced significantly since 1986.

Charles Thomas
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    "The video captured" is somewhat misleading when you write about a movie taken on film. Some formating of your answer would be nice to improve readability. – Uwe Jan 01 '19 at 13:50
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I don't know if this is a reason, but the grain of film is a silver halide crystal. They are only a few atoms and thus much smaller than a chip pixel can ever be. So at least at the focal point of the lens, film has a resolution advantage.

Johnny Robinson
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    This answer would be better if you can add a reference. Of course it is probably often true, depending on which particular film is being compared to which particular sensor, a number would be nice. Certainly the total number of "pixel equivalents" that can be recorded on a single piece of film is larger than a single sensor, especially for the larger film formats, and the best diffraction-limited optics can certainly take advantage of that. – uhoh Feb 14 '18 at 00:31
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    There are films with high and low sensitivity. Only a film with very low sensitivity has very small silver halide crystals. But a film with very low sensitivity may be used only at a day with full sunlight and no clouds. See wikipedia for film sensitivity and grain. High sensitivity film has large crystals and a visible grain limiting the resolution. – Uwe Feb 14 '18 at 09:54
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    Some good information about film grain size is here. High resolution film has a particle size of 48 nm (nanometer). But motion picture positive film particles are much larger, about 300 nm. Much larger than a few atoms only, but still smaller than pixels on a image sensor chip. – Uwe Feb 15 '18 at 10:14