A question about studio flash power

Hello,

Well I know you geniuses (geni?) must get sick of answering noob questions on studio lighting, but please bear with me and if you can offer any help it will be greatly appreciated.

I am seriously considering investing in a basic kit for full-length portraits and I am reasonably gen'd up thanks to the experts on this site and the search facility!

I understnd about guide numbers and watt/seconds but what I'm still failing to understand is how good some of the lower-end kits would be with the purpose above.

I'm looking at these kind of things:

http://www.hiltonphoto​.co.uk/products/detail​s/9235.html
http://www.hiltonphoto​.co.uk/products/detail​s/14991.html
http://www.hiltonphoto​.co.uk/products/detail​s/10407.html

The first two are 110 and 150w/s the last is 250. Would I need more than this? Sadly I don't have a limitless budget right now, but I am looking for something that I could potentially cart along to balls and parties, do some shots of the guests and make a little extra cash to fund my addiction to L glass (and maybe a more powerful studio kit at some point!)

I've been a bit spoilt to date as I have used a local studio a couple of times with a lovely four-head 500w/s Bowens set-up but do I really need this much power for full length portraits?

Now those links above point to two head systems, but then there is this Portaflash kit which is four heads for a really low price. Any good? Anyone got experience of Portaflash units?

Thanks for your help in advance.

Andy

Thought about this - half the price ..... No idea if it is any good or not.

http://cgi.ebay.co.uk …Z3860QQrdZ1QQcm​dZViewItem

I think 150-200 w/s and ability to have fractional power output would be enough for each light. Hard to state, since there is no true measure of light output by the w/s rating...that only indicates how much power is held in the storage capacitors that drive the flash tube, nothing about the efficiency of the reflector system, angle of coverage, degree to which power is lost in the use of umbrellas or softboxes.
Both units mentioned in both posts are relatively low power modelling lights...60w or 75w. That is very very low intensity if the lights are to be used in any room with windows in daylight...amost useless! Fine in a room with no window, or at night. You want a unit with 150 w/s modelling light at a minimum, if you have windows and daylight to deal with. Since you want to cart equipment around to do shots, you need equipment that will cope with the variables of on-location portraiture.

Well, shooting full-length portraits does take more light because you will be moving the lights back to get better coverage, and when you double the distance you need 4x the amount of light. In other words, if a 100 WS light gives you f/5.6 at five feet, then at ten feet you will need 400 WS for the same exposure. Also, with full length shots there is the tendency to need larger umbrellas or boxes in order to get the same soft quality of light and larger sources require more power. So 400WS lights would be preferable, but you could compromise by using 200 or 250WS and increasing the ISO to 200 without significant quality loss.

Thanks chaps, useful info...so realistically I should be looking for at least 200w/s by the sounds of it...at least to start off then if I make any money out of it I might upgrade at a later date!

IMO it's more important whether or not the flashes can be stepped down. I use a Lumedyne 'Classic' set (lovely: no mains needed!), and rarely use it at it's full setting. (If needed, I'll use higher ISO). I would have liked the ability to set the power in half stops though. As mentioned before: As a modelling light 60W is not enough unless you're in a basement

It's been said a number of times that AlienBees are about the cheapest studio lights worth bothering with, though there is one other brand that's slightly cheap that B&H sells that's mentioned sometimes by a couple of reliable people around here. I'd rather have one good light with modifiers, than three poor ones.

Sadly we don't have the Alien Bees here in the UK, as I've only heard good things about them from you chaps on the other side of pond.

Alll AB's are direct order...even in the USA.

See: http://www.alienbees.c​om/international.html for international ordering.

John