2008-05-22

How the HF100 controls exposure

If you press the Photo button on top of the camera half down the current arperture and shutter speed get displayed. You will notice that these two settings change very little when you point the camera to brighter or darker scenes.

Unlike a professional camcorder the HF100 does a lot behind the curtain. To control exposure it uses:

  • Shutter speed
  • Arperture
  • Gain in low light
  • Most likely a variable neutral density (ND) filter in bright light

So rather than changing the arperture or shutter speed, gain or ND filter come into play. A ND filter does no harm it only controls the amount of light but gain is bad. Gain is electronic amplification of the sensor signal similar to the ISO setting on a photo camera. As you probably know a small sensor and high ISO means noise. The same is true with high gain. Just like you want to shoot at ISO 100 to get good looking pictures with a minimum of noise you want to shoot at zero gain.

I don't know a trick to display the gain used by the HF100. If you read this article about controling exposure on the HV20 you'll see that the only way to expose the gain setting of a particular recording was to put the tape into another camcorder model and to display the info there.

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