I work for a furniture company and we are getting ready to invest in photography equipment to do our own in house photography for mostly web and some print. Most of our photos will involve individual pieces of furniture on a white sweep background. Medium sized sofas will be our biggest pieces to shoot. Of special consideration is getting good lighting with a clean "pure white background", and getting colors to be accurate to the actual fabrics. We shoot greens, browns, and reds which are often problematic.
We are considering getting the following:
A Canon 5D with an EF 15-35mm f/2.8L lens
My question regards this lighting:
Alien Bee B800 Monolight
They rate it at:
320 True Watt Secs./800 Effective Watt Secs.
Flashpoint II 1220 Monolight
They rate it at:
600 True Watt Secs.
I gather that they rate their watts differently, and that it may be skewed to the high side. I'm guessing that this type of rating is similar to the power ratings that I am familiar with for car stereos. An amplifier for a stereo is rated in RMS Watts. The true RMS Watts represent the realistic power available from the amplifier at any given time. Peak RMS is a figure that represents the maximum power the amplifier could put out in an "ideal" situation. In other words, if an amplifier is rated @ 800 RMS Watts, and it's Peak RMS Watts is 1,000, it's likely that the ONLY time you are going to get 1,000 Watts out of the amplifier is when you have a perfect 12 Volt power source, and even then, only for about 30 - 60 Sec. until the amplifier heats up and it begins to drop in power to cool down the electronics.
So my question is, in theory, is True Watt Seconds vs. Effective Watt Seconds similar to the power rating system I described above for amplifier ratings?
If my assumption is correct, would I be better off going with the B1600 rated at 640 True WS because that is a more accurate comparison to the Flashpoint II?
If that's the case, then we would probably opt for the Flashpoint II, because a set of two lights would be $127 cheaper then buying 2 Alien Bees 1600s.