On Camera Diffusers/Bouncers

[jlykins]

I like the Gary Phong piece because It is quick to change out to be directional if you need it. There are inserts that slip into it to make the light just go through the top thus diffusing the light. I like them for weddings IMHO.

 

[Mike_E]

The dirty little secret is that it doesn't really matter that much about on camera diffusers (please don't lump an off camera diffuser -ala Dean Collins with this) no matter how nice they look the actual light source is only going to be so big and it's the size of the light source relative to the subject that makes all the difference. The only time that I can think of that it would be really useful is in a huge room that you couldn't bounce your flash for any real effect. For the most part they just eat power. A lot of really good photographers just aim their flashes back over their heads or shoulders and don't worry about it.

The bounce card and it's variants expand the light source to the same extent as the diffusers but have the added benefit of allowing the light that would have otherwise been eaten to bounce from the ceiling or wall or where ever and further raise the light hitting the subject and the background. Not having someone look like they were floating in space can be a good thing too.

There is also the matter of the inverse square law governing the single point light source that is a flash tube- even through a difuser. Reflected light is governed by a different law but I'm not going to be the one to explain this.

If you haven't, do read Neil's page there is a lot of good info on all this.



P.S. a real softbox has an area of around 1700 square inches(or more), an on camera diffuser has around 12.

 

[Bifurcator]

The dirty little secret is that it doesn't really matter that much about on camera diffusers (please don't lump an off camera diffuser -ala Dean Collins with this) no matter how nice they look the actual light source is only going to be so big and it's the size of the light source relative to the subject that makes all the difference.

Very very true. There's a MASSIVE amount of difference and the two are simply not comparable!

The only time that I can think of that it would be really useful is in a huge room that you couldn't bounce your flash for any real effect. For the most part they just eat power. A lot of really good photographers just aim their flashes back over their heads or shoulders and don't worry about it.

Hmm, no, it's actually a different look all together. And remember that bounced light takes on the color of the surfaces it is bouncing off of. So, if behind you is a kitchen with yellow wall-paper and red cabinets you're going to get orange people if the flash is pointed back behind you.

The bounce card actually gives you two light sources both bounced:

The bounce card and it's variants expand the light source to the same extent as the diffusers but have the added benefit of allowing the light that would have otherwise been eaten to bounce from the ceiling or wall or where ever and further raise the light hitting the subject and the background. Not having someone look like they were floating in space can be a good thing too.

I'm not sure exactly what you mean here but a diffuser cap, a light-sphere or dome, an on-camera softbox, and a bounce-card produce four separate and different effects. Unlike Dean Collins lighting with huge reflector and translucent panels, these four are comparable. Different but comparable.

 

[dEARlEADER]

I don't really have technical data to support my claims.... but I achieve different looking images using a fong(cloud)... namely in the lighting of the eyes... there are lots of situations where bouncing is undesirable and/or unachievable.... colour casts, mirrors, high ceilings, those cheesy prism things hanging from lights etc...

i just find them so big clunky... i also use a small sto-fen... or sometimes nothing at all..

technical data aside.. you should just use whatever presents the best results for the environment you are shooting in....

 

[ksmattfish]

Not having used a bouncer/diffuser before, I think I am attracted to the "softbox" ideas, just from the great results of real softboxes and strobes in the studio.

If I can't bounce I use small softboxes, but they are still really small compared to bouncing off a ceiling or wall.

 

[Big Mike]

We really should point out the difference between flash accessories that actually soften the light themselves (a softbox) and accessories that are meant to be used while bouncing the flash off of something (pretty much everything else).
To actually soften light, you can do two things; make the source bigger or move the light closer to the subject....that's it. Just putting a translucent material over the flash, won't make the light softer, unless it significantly increases the size. So even that softbox I linked to, really only does much good when you are rather close to the subject.
As most of the other accessories are meant to assist while bouncing, it would be beneficial for you to understand the ins and outs of bouncing a flash. As mentioned, some people just point the flash behind them and that's it....no accessories required. The main benefit of most of these, is that they split the light, allow some to go forth and bounce (off a wall or ceiling) but also sending some forward, directly to the subject. This is good, because the direct light fills in the shadows caused by the light coming from the bounce surface. A good example of this is the Lumiquest Promax system with it's 80-20 unit. It allows 80% of the light to go out and bounce, while deflecting 20% of it forward for fill. I've got the promax system but don't use it much because it's not as useful when the flash is horizontal rather than vertical. It's great when the flash is always vertical though.
So if you do have a good handle on bouncing the flash, then all you really need is a simple bounce cards, because most of the accessories do pretty much the same thing.

Lastly, I think that it's important to recognize when your flash accessory won't be helping you...and when it will be actually hurting you. This is, I think, the most overlooked part of using these things. I've seen many, many professional photographers using these things in situations where it's utterly pointless to be using them.
You should not be afraid to use bare flash when your accessory won't be of use. This is another reason I like the Demb unit, it's got a nice hinge, so I just fold the card back and out of the way and use bare flash when I need it.
A flash head is (or is similar to) a Fresnel lens...it directs the light out in a beam. This is what gives these small flashes their great range. I read somewhere that a Canon 580EX (bare) can put out similar light to an Alienbee B800 light (with standard reflector). However, if you put a diffusion material in front of them, the flash unit is now several stops behind the studio light...I assume it's because when you diffuse the light, you destroy the beam properties from the flash head.
So by using bare flash, you have a great range and you're not working the flash nearly as hard as you do when it's bounced & diffused. This lets the flash recycle faster, which gives you better opportunities for getting the shot...and it also makes your batteries last longer.
Of course, the key is knowing when your accessory will help and when it won't.

 

[dEARlEADER]

Of course, the key is knowing when your accessory will help and when it won't.

good post Mike... can you give us some scenarios where use of an accessory is appropriate?

 

[Big Mike]

The way I see it, you should bounce the light whenever you can. So if you are indoors and have anything decent to bounce the light off of, then go for it. At the same time you need to realize how that bounced light will look on your subject. If that light is coming down on them from above, you have basically recreated mid day sunlight, which we know isn't great, because it casts shadows on your subject's face, especially in the eyes. So in that case, an accessory that puts some of the light forward, would be a good choice.
If you are in a smaller room, with good walls and ceiling for bouncing, then something that spreads the light around would be appropriate (if you want really soft light and no shadows). This is where the Lightsphere works well. It spreads the light around and it bounces off all surfaces to eliminate shadows or at least fill them in.

A big issue for me, is how you use flash when you rotate the camera. With a lot of accessories and with bare flash, the flash is off to the side when you rotate it, which can cast side shadows behind your subjects...if there is a wall or something behind them. In a smaller room, the lightsphere type accessories can spread the light enough to fill in those back shadows, so they work practically the same whether the the flash is on top or to the side.
When using bare flash, a flash bracket is good for keeping the flash above the camera in both orientations. I uses to use a flash bracket quite a bit...but I found that it was hard to bounce the flash while it was horizontal above the camera, especially when I wanted to use an accessory to put some light forward. A solution to my problem would be a 'camera rotate' bracket...but I haven't tried one yet.

 

[hacksaw35]

Thank you for all the opinions and responses. It was very informative. I think I am going to get a Demb, and read some more about effectively bouncing...then later down the road I might pick up one of the others and give it a whirl.

Thanks again.

 

[Mike_E]

Hmm, no, it's actually a different look all together. And remember that bounced light takes on the color of the surfaces it is bouncing off of. So, if behind you is a kitchen with yellow wall-paper and red cabinets you're going to get orange people if the flash is pointed back behind you.



I'm not sure exactly what you mean here but a diffuser cap, a light-sphere or dome, an on-camera softbox, and a bounce-card produce four separate and different effects. Unlike Dean Collins lighting with huge reflector and translucent panels, these four are comparable. Different but comparable.

As to the different look, yes but I was trying to point out that in a situation where there is nothing to bounce your flash from within the range of the flash the tupperware finds it's use. In any other case -imo- the quality of light (quality of the shadows I should say) is superior using bounced flash. As to the color, shooting in RAW is the cure for that. Sometimes time consuming but worth it I think.

As to the last, I was just trying to point out that the bounce solution is more efficient and lifts the ambient for a better environmental feel to the photo.

 

[Bifurcator]

As to the different look, yes but I was trying to point out that in a situation where there is nothing to bounce your flash from within the range of the flash the tupperware finds it's use. In any other case -imo- the quality of light (quality of the shadows I should say) is superior using bounced flash. As to the color, shooting in RAW is the cure for that. Sometimes time consuming but worth it I think.

As to the last, I was just trying to point out that the bounce solution is more efficient and lifts the ambient for a better environmental feel to the photo.

Yup... I know... I was attempting to heighten interest by agreeing (and adding) in a controversial tone.

We seem to be on the same page in all.