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Video tap is a video camera that is connected to film camera viewfinder so that crew can view material on a monitor and also record preview quality image (the v

Video tap is a video camera that is connected to film camera viewfinder so that crew can view material on a monitor and also record preview quality image (the video taps)

moosedev 4y ago
I'm guessing it's derived from plumbing jargon[0], in the sense of inserting an access point into an existing system to gain access to the resource inside; this idea is also found metaphorically in the common phrasal verb "tap into"[1] (make use of or gain advantage from an existing resource). [0] https://www.mcwaneductile.com/blog/what-are-the-three-pipe-tapping-methods https://www.mcwaneductile.com/blog/what-are-the-three-pipe-t... [1] https://dictionary.cambridge.org/us/dictionary/english/tap-into https://dictionary.cambridge.org/us/dictionary/english/tap-i...
- wildzzz 4y ago
  They are sometimes called taps in the RF industry. It's for when you want have a monitor port for a signal without disrupting the original signal too much. You'll still lose a little bit of power on the original signal but this will only be as much as 3dB for a splitter (where both outputs are equal in power) or much less for something like a 15dB coupler (the monitor signal is 15dB less than the original output). Since it's impossible to measure an RF signal without stealing at least little bit of power, there is always just a little bit of loss on the original signal. There are similar devices for fiber optics where they bond a fiber to the original so some light escapes the original fiber and goes into the second bonded fiber. This can even be done in the field on in-use lines where a tap fiber is wrapped tightly around the main fiber and bonded with a torch. You can even tap a fiber line by just bending it enough and placing a detector at the bend since some light will escape there. Something similar can be done for light where a diagonal piece of glass sits in front of one camera and another camera sits 90deg pointed at the same glass. Some light gets through the glass but most reflects so one camera sees a slightly darker image and the other sees a much darker image.
- yawpitch 4y ago
  It’s etymologically from the notion of tapping a keg or barrel… you literally had to tap (hammer) a tap (cone-shaped cork, bung, or — eventually, but much later - a plumbed faucet or tap) into a vessel to access the contents. Technically the video tap is the beam splitter and associated mounting affordances and hardware that redirects light bouncing off the mirror shutter to both the operator’s viewfinder and to the video assist camera; you could mount a 100% tap, replacing the viewfinder entirely, or various degrees of partial beam splitter. In either case the tap allowed you to capture video footage of what the camera operator was seeing… which, confusingly, was exactly what did NOT actually end up in the final film, since both the viewfinder and assist can only receive light when the shutter is closed and the film is moving to the next frame.
  - moosedev 4y ago
    Of course, I forgot about kegs/barrels. I can well believe that that's the older etymology. Thanks!
Gordonjcp 4y ago
Ah, we call that "video assist" here.
- yawpitch 4y ago
  To be accurate the video tap is the hardware assembly that allows video signal to be recorded at the same time as the film is being exposed — or very nearly the same time, since the film can’t be exposed while the video camera is receiving light — and video assist is the production technique of using that tapped video to aid production work (VFX, editorial, cinematography, playback, continuity, etc) while the exposed film awaits processing and scanning. In other words you needed a video tap to allow for video assist.
dylan604 4y ago
It's also the name of a connection when you have a single video signal sent to a distribution amplifier so that it becomes a 1-to-many signal. Each of the output connections is referred to as a tap.

Video tap is a video camera that is connected to film camera viewfinder so that crew can view material on a monitor and also record preview quality image (the video taps)

moosedev 4y ago

I'm guessing it's derived from plumbing jargon[0], in the sense of inserting an access point into an existing system to gain access to the resource inside; this idea is also found metaphorically in the common phrasal verb "tap into"[1] (make use of or gain advantage from an existing resource). [0] https://www.mcwaneductile.com/blog/what-are-the-three-pipe-tapping-methods https://www.mcwaneductile.com/blog/what-are-the-three-pipe-t... [1] https://dictionary.cambridge.org/us/dictionary/english/tap-into https://dictionary.cambridge.org/us/dictionary/english/tap-i...

wildzzz 4y ago
They are sometimes called taps in the RF industry. It's for when you want have a monitor port for a signal without disrupting the original signal too much. You'll still lose a little bit of power on the original signal but this will only be as much as 3dB for a splitter (where both outputs are equal in power) or much less for something like a 15dB coupler (the monitor signal is 15dB less than the original output). Since it's impossible to measure an RF signal without stealing at least little bit of power, there is always just a little bit of loss on the original signal. There are similar devices for fiber optics where they bond a fiber to the original so some light escapes the original fiber and goes into the second bonded fiber. This can even be done in the field on in-use lines where a tap fiber is wrapped tightly around the main fiber and bonded with a torch. You can even tap a fiber line by just bending it enough and placing a detector at the bend since some light will escape there. Something similar can be done for light where a diagonal piece of glass sits in front of one camera and another camera sits 90deg pointed at the same glass. Some light gets through the glass but most reflects so one camera sees a slightly darker image and the other sees a much darker image.
yawpitch 4y ago
It’s etymologically from the notion of tapping a keg or barrel… you literally had to tap (hammer) a tap (cone-shaped cork, bung, or — eventually, but much later - a plumbed faucet or tap) into a vessel to access the contents. Technically the video tap is the beam splitter and associated mounting affordances and hardware that redirects light bouncing off the mirror shutter to both the operator’s viewfinder and to the video assist camera; you could mount a 100% tap, replacing the viewfinder entirely, or various degrees of partial beam splitter. In either case the tap allowed you to capture video footage of what the camera operator was seeing… which, confusingly, was exactly what did NOT actually end up in the final film, since both the viewfinder and assist can only receive light when the shutter is closed and the film is moving to the next frame.
- moosedev 4y ago
  Of course, I forgot about kegs/barrels. I can well believe that that's the older etymology. Thanks!

Gordonjcp 4y ago

Ah, we call that "video assist" here.

yawpitch 4y ago
To be accurate the video tap is the hardware assembly that allows video signal to be recorded at the same time as the film is being exposed — or very nearly the same time, since the film can’t be exposed while the video camera is receiving light — and video assist is the production technique of using that tapped video to aid production work (VFX, editorial, cinematography, playback, continuity, etc) while the exposed film awaits processing and scanning. In other words you needed a video tap to allow for video assist.

dylan604 4y ago

It's also the name of a connection when you have a single video signal sent to a distribution amplifier so that it becomes a 1-to-many signal. Each of the output connections is referred to as a tap.