Umbrellas--what's the deal?

[mr_v_s]

I'm after Lastolite's All-in-one solution for my flashguns. I've got an SB-800 and an SB-900 and want a portable flash set-up using Nikon's CLS.

Question is they offer two sizes of umbrella. A 40inch one and a 34 inch one. Am I correct in assuming that the larger the umbrella, the softer the light will be? If so is it wise to invest in a 40 inch umbrella for fill light and a 34 inch umbrella for a key light? Or would two 40-inch umbrellas do the job?

I've done a search and found that a certain user invested in a kit and it looks absolutely fab!

Any help much appreciated.

Thank you.

 

[EmZee]

Here's one source of information which might begin to explain using umbrellas: http://www.scantips.com/lights/umbrellas.html

 

[Garry Edwards]

That's a very good link, with really useful info in it.
But to answer your question...
1. Size doesn't matter. what matters is relative size. In other words, if you have a large light source (softbox, scrim, umbrella, whatever) and place it a long way away it will become small relative to the subject and so can't produce soft light. If you want soft light then your light source needs to be close, and the closer it is the softer the light will be.
2. There are 2 basic types of umbrella. Reflective umbrellas face the 'wrong way' and reflect the light from the flashgun/studio head towards the subject. Because of this the light is fairly directional but can't be soft, because the design stops it from being placed close to the subject. Because the light is fairly directional reflective umbrellas can make a good key light, if you don't want the light to be too soft.
3. Shoot through umbrellas face the 'right way' so that it's the umbrella that's facing the subject, not the flashgun. Because of this the umbrella can be placed close to the subject and so can produce soft light. But the light spills everywhere, it's very uncontrolled and also loses about twice as much power as a reflective umbrella because of the light that is reflected from the diffuser. I'm not saying that because of this a shoot through is never suitable as a key light, but it isn't ideal.

So, a good starting point would be to have a medium/large reflective umbrella as key light (say above the subject or above and off to one side) and move it closer or further away to control the harshness of the light, and have a shoot through as fill. Fill lights have to be on the camera axis, either immediately above, immediately below or behind the camera - never to one side, as the light source has to illuminate all of the subject as seen by the lens.

Please see this basic guide to portrait photography. You'll see that there's a lot more to lighting than umbrellas, although using hotshoe flashes will seriously limit the range of light shaping tools you can use.

Hope this helps.

 

[Bob]

Very good article will have to finnish later thanks for the link
Bob

 

[Kev M]

I'd go for two 40" umbrellas, if you want a smaller light source without moving the setup just zoom the flash head in a bit.

 

[mr_v_s]

Superb, thank you for the links and information, very helpful.

I have been using continuous lighting for set-ups (3 x 800w Arri-lights) but wanted to supplement their use with a portable flash set-up.

I used to hate flash and never used it at all but I'm growing to like it a lot!

 

[Garry Edwards]

Superb, thank you for the links and information, very helpful.

I have been using continuous lighting for set-ups (3 x 800w Arri-lights) but wanted to supplement their use with a portable flash set-up.

I used to hate flash and never used it at all but I'm growing to like it a lot!

Even hotshoe flash is better all round than your redheads. If you use one to supplement the light from the other you'll have to gel the flash to match the colour of the redheads, which will reduce the power substantially.

 

[mr_v_s]

Yeah did this yesterday as I was practicing white-balancing with flash and continuous light. I used the orange filter on both speedlights to match the tungsten light from the Arri. It was alright! I need to play about a bit. Done quite a bit of behind-the-scenes work on soundstages so prefer the look of continuous light but I can definitely see the benefit of flash. The SB-900 is amazing as well!