Is the following correct about Automatic Gain Control (AGC)?
  1. Automatic gain control (AGC) was a feature added to VCRs.
  2. The goal was to adjust the brightness of the video image to keep it as close to the middle as possible (similar to how some televisions have a feature to reduce the sound automatically if there is a very loud scene).
  3. The anti-copying feature of Macrovision soon followed in VCRs through an ingenious/devious use of the AGC feature, by fooling the recording VCR to auto adjust the video image to be too bright or door dark, thus ruining the copy.
  4. Many (all?) external frame TBCs have the ability to ignore Macrovision's ingenious/devious use of the AGC feature.
  5. Some analog-to-digital capture devices have the AGC feature, but many older capture devices from ATI and others do not.

Question: Is the AGC feature in many modern capture devices meant to improve video capture by adjusting brightness on the fly? Or is AGC forced into capture devices to comply to anti-piracy rules?

Question: Is AGC a good thing for capture hobbyists or a bad thing?