Outdoors Fill Flash - Sto-fen or Bare Flash?

mgbeach wrote in post #913239
I've got a shoot this weekend where I'm going to do a similar test to the one in my other post, but outside. Hopefully we'll put the issue to bed.

Kind of late to the party on this one, but was this ever done?

Mr. Blue wrote in post #12141699
Kind of late to the party on this one, but was this ever done?

Its been done numerous times in other threads here. The results always show the stofen doesnt do anything significant.

gonzogolf wrote in post #12141732
Its been done numerous times in other threads here. The results always show the stofen doesnt do anything significant.

I see. I have to admit that I didn't do any searching...this thread is the first one that popped up in my google search: "stofen omnibounce outside"

Seems most of my questions have been answered by the google search > 1st hit POTN thread. Pretty cool actually.

The Stoffen reduces effectiveness of fill flash outdoors, in diminshing the contrast of shadows cast by the sun! This old (2008) test series should prove it to you.

First, sun only

This is an interesting discussion. I've been reading up on diffusers and thought I would cast my vote on the side that says their usefulness is limited.

Here are a couple of things to keep in mind: 1). The larger the light source in relation to the subject, the softer the light will be. 2). Light can reflect (bounce off a surface), refract (change angles when going through a substance), or diffract (bend around an object or spread when passing through a small opening).

Based on the above, my understanding is that The Sto-Fen Omni-Bounce causes light to refract (go in different directions) because the light of the flash is passing through an opaque substance (plastic). Sto-Fen's website shows an illustration of this refraction at http://www.stofen.com/​info/howitworks.asp.

The illustration on this page recommends pointing the flash with the Omni-Bounce at 45 degree angle to the subject, which will throw some of the light directly on the face to fill in shadows, and refract the rest if the light so that it reflects off the walls and goes back onto the subject. The light bouncing off the walls is now a large light source in relation to the subject and produces softer shadows.

The refraction interfering with the flash sensor probably also why Sto-Fen says to point the flash at a 45 degree angle:

The Gary Fong LS works the same way. If I had to guess, between the Omni-Bounce and the LS, I'd say the LS works better because is is bigger and causes more refraction. But it is also probably less efficient energy wise than the OB. But I don't know if the differences between the two are noticeable in either case.

With the Demb Bounce Card, the majority of the light from the flash is bounced off the ceiling while the bounce card reflects some light forward to the subject fill in the shadows under the eyes, nose and chin.

The cost of refraction is loss in efficiency. Sto-Fen's website (http://www.stofen.com/​info/faq.asp) says,

Because the diffuser or direct flash is still lighting the face evenly, the lighting is flat, which is not the most interesting or flattering light for a subject.

The same results can be achieved as with a diffuser by bouncing the flash off a back wall. However, even more pleasing results can be achieved by bouncing the flash off a side wall or a reflector placed to the side of the subject. If there is nothing at all to bounce the flash off of sideways, and all you have is a ceiling, then perhaps the diffuser is useful in that scenario. But then again, if there are no side walls, then you don't have to worry about shadows with a direct flash, so why bother with a diffuser? Direct flash used correctly in that scenario (dialed down) will probably achieve the same results.

Outdoors, the only things a small diffuser will do is waste energy. Direct flash dialed down will achieve the same results more efficiently.

So why bother with soft boxes and umbrellas then? For two reasons:
1). Because the surface area of those items are much larger than the surface of the Sto-Fen, the light source is now larger in relation to the subject, which results in softer shadows.

2). Because you can use directional lighting with them. A flash placed at a 45 degree angle to the subject will produce more pleasing shadows than a flash pointing directly at the subject regardless of whether or not a diffuser is used.

Based on my currently level of understating, diffusers do produced better results indoors than what pointing a flash directly at someone will, but light bounced off a back wall will produce the same results for free. But light bounced off a side wall or object will produced even more pleasing results.

Outdoors, small diffusers do nothing but waste energy.

That said, if I am indoors and have no time to think about how I will bounce my flash, I'm slapping a diffuser on. A diffuser would also be useful if I have dialed my flash down as far as it will go and I am still over exposing a subject. In that case, a diffuser would help me reduce the light my flash is producing by about another stop.

I'm constantly learning, so the opinions I have now are subject to change.