Gain in your videocamera?

[sorvju-f]

I have lately wondered the meaning of gain in videocamera...what it actually do. In my camera you can choose gain either to be fixed or adjustable.

Is it like ISO in still camera?

Jukka

[Neptune7]

Exactly! Increasing the gain increases the sensitivity of the sensor but at a price: it also increases the "noise" and the quality decrease. Like an 800 ASA film you would get grainier pictures than using a 200 or a 64 ASA speed film...
Pierre

[Jonathan Bird]

Mon Ami, I am so proud of your technical explanation!

[Neptune7]

Thank you master. You taught me well!

[sorvju-f]

Thank you master. You taught me well!

My Masters:D

Are you using gain adjustment and in what circumstances?

Jukka

[Jonathan Bird]

I try to keep the gain down if possible. For example, if the light is crappy and I flip the UR pro filter on, I will check the gain. If it's over 6 dB, I will flip the filter off because the image will look better being too blue than too grainy, as far as I am concerned.

As cameras get better, they need less gain to form an image in low light and as a result the image is cleaner. This is where we are going to see the largest improvement in HD cameras with time. Right now there is no place for resolution to go...but image quality can be improved quite a bit with regard to low light performance.

Older SD cameras, like the VX2000 were very good in low light....much better than the current generation of HD cameras, because the pixels were larger. As the pixels get smaller to produce HD on a chip the same size as an SD chip, the low light performance suffers.

Jonathan

[Neptune7]

Hi Jukka,
When the camera is on full auto (gain, iris), the gain will engage when the light is low. This how the Z1 can boast sensitivity to 1,5 Lux... When you desengage the automatism, the performance in low light his greatly reduce.

In the housing, I usually leave the camera on full auto except for focus.:rolleyes:

Pierre

[Jonathan Bird]

In the housing, I usually leave the camera on full auto except for focus.:rolleyes:


Ahemmm......:rolleyes:

[Neptune7]

Ok Ok not always manual focus...:o

[Jonathan Bird]

Lol! :) :)