Frequency Of Light

[darmanb]

I know that electronic ballast is the key to get the higher frequency of electronic light source.
My question is: do all new video lighting kits include ballasts?
If not, which ones do?
Prices?
Stores suggestions?

Thanks

[J_Barnes]

Re: Frequency Of Light

Ballasts are only used with enclosed AC or DC Arcs (metal vapor) and AC discharge sources (fluorescent). CID, HMI, HID, DCI, Fluorescents and high-pressure short arc xenons all require ballasts to operate both for the initial ignition and to regulate the power modulation that causes flicker.

There are two types of ballasts, magnetic and electronic. Magnetic ballasts are cheaper, older and heavier and operate using large internal transformers. They're pretty reliable, noisy and allow for specific windows of flicker free camera operation depending on your country's power cycle.

Electronic ballasts work, as you say, by raising the frequency of the lamps operation, reducing the effect of the "off" cycle on camera. They also convert the sinusoidal AC wave to a square wave, further reducing the flicker seen on camera.

For video, you should always go with an electronic ballast.

Now as far as specific suggestions, perhaps you should go into more detail as to what kind of lighting kit you're looking for. There are a vast variety of incandescent lights used in filmmaking, none of which would require a ballast.

[darmanb]

Re: Frequency Of Light

Thank for a lot of useful info!!!

Anyway, I am trying to get a kit which will have 3 tungsten ballanced lamps (maybe up to 1KW), barndoors, stands and softboxes.
The kit is required for no specific setup, maybe for general and minimized indoor use.
I will be operating on 50Hz mains.

Thanks

[darmanb]

Re: Frequency Of Light

And of course, I want to be able to play around with the shutter speeds without flicker problems.

[J_Barnes]

Re: Frequency Of Light

If you're using tungsten lighting, you're not really going to have flicker problems. You should be able to crank your shutter any way you like without it showing on camera.

People recomend the Britek/rostronics kits most often on this site. I think they look kinda cheap (admittedly I've never used them), but they won't hurt your pocketbook much. So it might be your best option.

For alternatives, keep checking ebay for used lighting equipment...especially old Mole Richardson fresnels, they're built like tanks and can be had for cheap. Of course, you mention 50 Hz, so ebay might not be such a viable option for you in (Bosnia?).

If money is no object, buy a new kit. Mole, LTM, Arri, desisti, lowel and dedolite all make kits in various ranges of usability and price. I'm not a huge fan of lowel, and desisti units can sometimes have problems, but the others are generally rock solid. I'd avoid anything from SV or Cool Lux.

[darmanb]

Re: Frequency Of Light

Many thanks for help!!!