Question about flash heads

[Remarcable]

I have a question regarding the "watt/sec" rating of flash heads. I'm a serious amateur photographer who is considering upgrading my ligting to a set of professional heads with a softbox or honeycomb grids. My "studio" (i.e. family room) is about 12 x 18, with much less of it usable for photography.

What output head(s) should I start with? 500 w/s, 1000w/s, or something more or less than that? And is there a rough conversion from my camera-mounted flash rating (Guide Number) to the w/s rating?

Thanks!

-Marc

[bsphoto]

With a room that sized you could get by with a 500 w/s power pack and 2 to 4 heads I would think. Or, if you're planning on getting monolights you would have more than sufficient light with 320 w/s units.

You should be able to get at least f 11 with iso 100 speed film in a space like that.

There's no conversion between watt seconds and guide numbers.

Watt seconds is a measure of power the capacitors hold, not a measure of light output. How much light a watt second produces is dependent on the design of the flash. Guide number is a measure of the exposure at 10' and ISO 100.

[That_Look_Photography]

I have 3 JTL mono lights rated at 300ws and that seems more then enough. Remember mono heads give you the full watt secs per head and flash heads share the power from one power pack.

Mike