Tompano1 1:06am, 1 February 2013
Right so here's something that's been bugging me for a while. If I have a 100 inch softbox that I flag so there´s only a square of 10 inches of light shining through. Will the softbox then behave as a 10 inch softbox or will it behave as a 100 inch softbox that only covers a tiny area?

Along the same notes, how about if I use a wide angle lens to spread my light from a tiny lightsource. Will the small lightsource then act as a large lightsource or will you just have hard light that' cover a lot of ground?

For clarification what I'm talking about is the quality of light or softness/hardness.
Tompano1 said:
Will the softbox then behave as a 10 inch softbox...


Yep.
AtlantaTerry Posted 4 years ago. Edited by AtlantaTerry (member) 4 years ago
about your softbox question: think about it in terms of potential. Your 100 inch softbox has a certain amount of potential output. But then you limit it by allowing only 10 inches of light to show though. Not only have you taken a wide soft light source but created a small light source so your shadows will go from soft to hard(er).

Use your light meter to determine the light loss.



About the wide and lens. I believe again you have a certain potential of light. But if you use a lens to spread out the light less is going to hit your subject (all else being equal).

As for the quality of light I believe your shadows will be about the same because the size of the light source has not changed that much.

Again, use your light meter and make some tests.
primeparry 4 years ago
What makes a light soft vs. hard? You might want to reread the explanation here: strobist.blogspot.com/2007/07/lighting-102-unit-21-appare...

Especially this part: "That is why larger-looking sources make for broad, smooth transfer zones. They disappear more slowly as you wrap your way around the subject away from the light source."

If you think about it that way and think about how the subject "sees" the light source, you probably have the answer to both of your questions.
Tompano1 4 years ago
Right then it is like I thought. Thanks everyone for answering my stupid question. And thaks to primeparry for the strobist link.
Tim Kamppinen 4 years ago
The lens (if I'm understanding correctly you mean some type of lens over your light, not a camera lens) that spreads out the light would just produce something similar to a bare bulb strobe that spreads the light in all directions. It lights up a broad area, but it's coming from a very small area, so at any one spot (like you're subject's face) all the light beams are coming from the same direction, which will produce hard edged shadows.

A large light source sends light at your subject from many different angles, which is what produces the soft edged shadows.
stan schurman PRO 4 years ago
With the softbox you're not going to get the same amount of light somehow concentrated into that 10" square. The source will be the same.

Same thing with the wide angle lens. The light source doesn't change, it will just spread the same amount of light over a more broad area, so more diffuse and less intense.
Mr. Speedlight 4 years ago
Will the softbox then behave as a 10 inch softbox or will it behave as a 100 inch softbox that only covers a tiny area?

Like 24x36mm (1x1.5") subject area as in a 1:1 image ratio? You might find a 10" softbox is a bit too big, a bit too soft if you move it in close to a subject of that size.

Dave Hartman
petepixxx Posted 4 years ago. Edited by petepixxx (member) 4 years ago
** Will the softbox then behave as a 10 inch softbox **

The biggest *problem* is the quality of light that is inside the softbox. They are designed for spreading and bouncing a light. If you put a focused light (speedlight) in a softbox the *quality* of light could be very different in the center vs. at the edges of the softbox. So, if there is a visible difference, pick your 10 inches from a good location.
MOD
Nionyn_ PRO Posted 4 years ago. Edited by Nionyn_ (moderator) 4 years ago
So pick your 10 inches from a good spot.
I'd like a hundred separate 1" squares from around the edges, please. :-)
mjkzz (a.k.a zwdeal) Posted 4 years ago. Edited by mjkzz (a.k.a zwdeal) (member) 4 years ago
"Along the same notes, how about if I use a wide angle lens to spread my light from a tiny lightsource. Will the small lightsource then act as a large lightsource or will you just have hard light that' cover a lot of ground?"

I think you will have hard light because putting a lens in front and make it bigger is NOT the same as diffusing the light source like a softbox does. It is probably similar to having a reflector like most speedlites do so that light from such source is very much directional
petepixxx 4 years ago
LOL !
Rangefindergeneral 4 years ago
A diffuser diffuses and a lens lenses.

A lens is about focusing the light so even if its over a large area its still hard.

A diffuser "breaks" the light up and scatters it in different directions. You just have to place it close enough or make it large enough for all that scattered light to hit the subject, then its soft or "filling shadows".

(See Father Ted)
alohadave 4 years ago
Rangefinder general:
a lens lenses


a lens focuses.
Alfredk PRO 4 years ago
It is the apparent size of the light relative to the size of the object that matters and not the actual size.

A 60" softbox is not so soft if it is located a far distance from the object, hence the sun is a harsh light despite it's actual size.

A tiny LED would make a great soft light source for photographing a flea.
FrankAG 4 years ago
I like wizwow's answer. Short & sweet.
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