Explain "spill" when using a softbox, please.

Thinking about buying a softbox of some kind for my Alien Bees. I have heard the term "spill" but I'm not sure what that means. Is that a bad thing? Also, is there some kind of baffle or modifier that can be placed inside the softbox to prevent that? Thanks in advance for your replies! Hank

Hank E wrote in post #11547078
Thinking about buying a softbox of some kind for my Alien Bees. I have heard the term "spill" but I'm not sure what that means. Is that a bad thing? Also, is there some kind of baffle or modifier that can be placed inside the softbox to prevent that? Thanks in advance for your replies! Hank

A softbox is a directional light modifier which projects light forward. Spill is when the light spreads out wider. I would say it's not a bad thing, but something you have to control. Without spill you won't have a soft transition of light to shadow.

You can control your spill or limit it throughout the use of grids/snoots

'Spill' is any light that falls where you don't want it.

Shoot-through brollies are absolutely the worst for it, unless you can make good use of all the light that bounces straight out of the back and all around the room, which is sometimes quite handy.

At the other extreme, a snoot should have zero spill.

And inbetween, there is everything else. A reasonably deep softbox shouldn't be too bad, but you can also get an extended front lip/surround to control it further, or fit a mesh grid which is usually very effective.

Good light modifiers are just as much about stopping light going where you don't want it, as they are about delivering a certain quality of light and putting it where it's needed. For example, the light coming directly from a 100cm shoot-through umbrella will be exactly the same as the light from a 100cm octo softbox - it's the perpheral spill from the shoot-through that bounces around the room and fills in shadows further, whether you want it to or not, that is the main difference.

visatec has a nice comparison photo section that shows different patterns on the subject, This may help you in your choice of modifiers to buy. The location is http://www.bron.ch …torials/light-comparison/ and it's a nice set up to see the effects of the modifiers. If you get a softbox also get a grid for it as this will help to focus the light better and if that doesn't cut enough light than you can look at using some matte black panels to absorb the excess light.

coffee_mon wrote in post #11549428
visatec has a nice comparison photo section that shows different patterns on the subject, This may help you in your choice of modifiers to buy. The location is http://www.bron.ch …torials/light-comparison/ and it's a nice set up to see the effects of the modifiers. If you get a softbox also get a grid for it as this will help to focus the light better and if that doesn't cut enough light than you can look at using some matte black panels to absorb the excess light.

Coffee_Mon, thanks so much. That's a very cool and helpful comparison.

babymilo wrote in post #11547097
Without spill you won't have a soft transition of light to shadow.

Not quite.

The soft transitions from light to shadow are relative to the apparent size of your modifier. The bigger the modifier, the smoother the transition...the smaller the modifier, the more harsh of a transition.

Spill, simply put, is light where you don't want it. You can control it by position of the softbox, putting a grid on the face of the softbox or positioning things to block the light on the sides of the box itself(cardboard, paneling, flags, etc).

look at a window in your house, and watch how the shadow transitions. ever wonder how light goes to the ceiling? that is the light spilling through the window