Watt-seconds in flash

[Herschel Mair <herschelmair@xxxxxxxxx>]

Hi Lea,

The WS (or Joules) specification used in studio flashes is a little misleading.

It's really a measure of electricity and not light. One manufacturer's  500WS  light may put out much more or less light than another's.

 

It's useful for comparing lights  in a single manufacturer though and you can be pretty sure that the Elinchrom 400WS light will give you twice the light output of the Elinchrom 200WS.

 

What you really need is the guide number (GN) with the umbrella or light shaper you will be using.

 

When thinking of watt-seconds,  think of   "WATTS PER SECOND"

 

A 500W tungsten lamp will give you, let's say,  f/11 at 1 second exposure. (500 WS)

A 250W tungsten light should give you f/8 at 1 second under the same circumstances (250WS)

 

etc.,

 

 

Herschel Mair
Head of the Department of Photography,

Higher College of Technology
Muscat
Sultanate of Oman

Adobe Certified instructor

 

+ (986) 99899 673

 

www.herschelmair.com

----- Original Message ----
From: lea murphy <lea@xxxxxxxxxxxxxxxxx>
To: List for Photo/Imaging Educators - Professionals - Students <photoforum@xxxxxxxxxxxxxxxxxxxxxx>
Sent: Friday, February 9, 2007 4:06:00 AM
Subject: Re: Elinchrom Studio Set

I'd buy it in a hearbeat. Elinchrom is some of the best lighting you can buy.

The heads are the lights themselves and 250 and 400 is the watts per second the lights can output. There's all sorts of technical stuff to explain it (and hopefully someone will) but one way to think of it is that it is like a guide number for your studio lights. Basically, the higher the number the more power and the faster recycling time.

This will be more than sufficient for studio work though you may, in time, wish to add a third light and softboxes instead of umbrellas.

Good for you and good luck.

Lea

On Feb 8, 2007, at 5:37 PM, Elson T. Elizaga wrote:

I'm planning to buy this set:

http://www.ebay.ph/viItem?ItemId=150089965064

What is 250 and 400 in the phrase "2 heads: 1x250 and 1x400"?

Watts? What do you think of the whole set in general? Is it sufficient for portraits? Food and jewelry photography?

I'm not a studio photographer so some things in this area are still baffling to me.

I've asked the seller already, but I'd like to get your opinion, too.

Elson

lea murphy

www.leamurphy.com

www.whinydogpress.com

blog: web.mac.com/leamurphy

---

Food fight? Enjoy some healthy debate
in the Yahoo! Answers Food & Drink Q&A.