Use camera's battery or AC cable during capture ?

[Music Fan]

Hi,
I'm wondering if the use of the camera's battery instead of its AC cable during analog (Hi8) capture could reduce or avoid problems (video noise) linked to AC (voltage variation, electrical interference ...).
Has anyone compared both yet ?

[Ghitulescu]

Most camcorders do not use directly the battery, but instead via DC-Dc circuits, similar to any modern switched-PSU.
I don't think this would make any difference, but an AC-adapter is always "full" :) :)
Besides, (ab)using the battery of a camcorder would shorten its life, and they are expensive (when or if available).

[Music Fan]

Most camcorders do not use directly the battery, but instead via DC-Dc circuits, similar to any modern switched-PSU.
I don't understand what you mean ; if I don't connect the AC cable, the current is delivered by the battery. Or there is still a step (voltage conversion) after the battery ?

an AC-adapter is always "full"
Do you mean it acts as a battery and deliver a current as "clean" as a battery ?

[Ghitulescu]

You got it wrong twice.
No battery in the world since decades delivers the energy directly to the apparatus. In particular the LiIon. So you'll end with the same noises anyway. Unlike audio, video should be immune to these interferences, in theory.
And by "full" I meant that the AC adaptor won't show "battery low" :) :) when you need it the most.

[Music Fan]

No battery in the world since decades delivers the energy directly to the apparatus.
What is there between battery and apparatus ?

So you'll end with the same noises anyway. Unlike audio, video should be immune to these interferences
Why ?

[Ghitulescu]

1. Most probably a DC-DC convertor, but also various regulators and stuff.
2. because the "noises" are much lower than the video spectrum.

[Music Fan]

1. Most probably a DC-DC convertor, but also various regulators and stuff.
I don't believe it can bring the same problems than the electrical network.

2. because the "noises" are much lower than the video spectrum.
Ok, but admitting it has no effect on video, and as there is also sound on video tapes, using the battery is maybe not so unuseful.

[Ghitulescu]

Use batteries then.