Diffuser usage....

I've just bought my YS25 strobe and they come with a diffuser. Can anyone tell me, what is the usage of it and why do we need a diffuser and when do we need to use it?

The diffuser helps to soften the light and shadows

If you look at a flashlight beam when you shine it on the wall you will notice an edge around the light beam. Place a diffuser in front of the light and that hard edge is softened out making the light appear wider. The edges of shadows within the light beam become softer too.

You will lose 1 stop of output from your flash gun with a diffuser in place and also the light temperature will drop giving a warmer image if shooting film.

You can use the diffuser whenever you like. If you are shooting digital then do a bunch of test shots and study the difference. See what you prefer.

You may need to use it for a wider angle view to knock off that "spot light" appearance. If you balance the flash with natural light then you shouldn't get this effect too much anyway.

You can go the oposite way and make a "snoot" which will enable you to squirt a very narrow beam of light from your flash gun for some very creative lighting. It is basically like a light proof funnel that fits over the flash gun.

You could get some excellent effective shots with digital but it is very hit and miss when using film.

Good luck

PauP

A diffuser can also help to limit back scatter.

............put it over your lens?

I generally use the diffuser when shooting macro. It seems to help avoid hotspots. And I like the slightly warmer colors.

Hi guys,

I'd have to agree with Jimbo here, the primary effect of a diffuser is to even out the intensity of the strobe over what is often a larger angle than the bare light. Topside, diffusers can offer softer shadows when they cause more reflections off walls and ceilings, but not as a direct result.

Softer shadows are only acheived as a result of enlarging the area of the lightsource, generally by using a large diffuser or diffuse reflector. This is why bounced light from a diffused source can work so well, but only if there are surfaces to bounce off - usually sadly lacking under water, except in the proximity of a sandy bottom.

You may also find that the broadening of the beam actually causes more backscatter, if it lights more of the water between the subject and the lens. So suck it and see, as they say.

HTH

Martyn

Basically, think of it this way:

When you use a diffuser and fire the flash, the whole diffuser "lights up." That means that instead of having a small flash tube firing a "point source" you have a big well distributed light source.

That means less backscatter, better coverage, softer shadows, and in some cases a warmer color light.

This is especially good for Macro where you can have VERY harsh shadows if you don't use a diffuser.

Hope that helps.

James