Anyone can explain theory of Omnibounce?


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dRebelXT

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May 14, 2005
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#1
Always heard of this concept, but google didn't give me the theory either.
What does that mean? :confused:
 

Firefox

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Feb 15, 2004
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#2
It acts as a diffuser. By allowing the light from the flash to be projected over a larger surface, it reduces the harshness of the shots taken..

A better unit would be the Lightsphere though... It's got a much larger surface area and further more, by projecting light over a curve surface, the resultant shadows are lighten more due to bounce over more surfaces..
 

Snow_One

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Apr 26, 2005
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#3
omnibounce is something you attached on your flash.... got theory one meh?

Learn more about flash.... how it affects your pictures

Try getting books/website on flash with key word :- bounce, direct, diffuse
 

seankyh

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#5
The one answer about Omnibounce I want to know is why do I pay 30 bucks for a piece of plastic??? But I bought it in the end..
Wait till someone starts making it in China..
 

yanyewkay

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Sep 22, 2004
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#6
plastics moulding dun come cheap. Even in china, the tooling alone would already cost you several K-USD..several THOUSAND USD.. moreover, the production of each omnibounce for different type of flash is in low quantity. Most likely you'll just buy 1 for that flash this lifetime (unless you lose it).

It'll be cheaper to DIY no doubt, but it's hard to make one as robust as the one sold.
 

dRebelXT

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#7
Wht don't the manufacturer of flashes make the omni also, since it would add on
some bargaining power.
 

kahheng

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Jan 20, 2002
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#9
seankyh said:
The one answer about Omnibounce I want to know is why do I pay 30 bucks for a piece of plastic??? But I bought it in the end..
Wait till someone starts making it in China..
You're paying $30 because Lumiquest is the only company supplying it. They can charge you whatever they want.

You used to be able to buy non-Lumiquest branded ones here for a short period of time, made in Asia (not sure if it's China or not), but it didn't become popular because, apparently, the colour of the material was not neutral enough for people's liking.

Yes, someone in China should start manufacturing these things. They are way too overpriced.

Why don't you DIY one out of a translucent bottle?

[update: as my arch-fiend below points out, it's a Stofen product; my bad]
 

kahheng

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#10
Firefox said:
It acts as a diffuser. By allowing the light from the flash to be projected over a larger surface, it reduces the harshness of the shots taken..

A better unit would be the Lightsphere though... It's got a much larger surface area and further more, by projecting light over a curve surface, the resultant shadows are lighten more due to bounce over more surfaces..
Permit me to elaborate on your explanation.

First of all, some fundamentals need to be understood:

The 'hardness' of the light incident on your subject is dependent largely on the size of the light source in relation to the size of the subject/object being illuminated (this is not all there is of course - but for simplicity's sake, we can assume it is) . All things being equal, the larger source of light will look softer than a relatively smaller source of light when both are directed straight at the subject from the same distance.

So if you illuminate someone for a head and shoulder shot with light from a large umbrella 60 inches across versus say the light coming from your usual hotshoe gun flash, both placed say 1.5 meters away, aimed directly at the subject, the light from the umbrella will look less harsh simply because it's a larger light source.

Before I go any further, understand that distance is a vital factor as well. If you pull the umbrella'd light source say 20 meters away from your subject, you'd discover that the light is now a lot more harsh than when it was 1.5 meters away. Bear this in mind.

Whether a source of light is large or small is relative to the size of the subject as well. A large softbox might be a big light source to illuminate a pot of flowers for a still life. The same lightbox becomes a small light source placed next to a large boat for instance.

Now, with this as basic background knowledge, let's understand how the Omnibounce works:

The first thing that the Omnibounce does is that it modifies the directionality of the light source from your small gun flash. The root word "Omni" basically means "all" and used in this case, it means that it modifies the light from your flash to be thrown in 'all' directions - or more accurately in much wider 3 dimensional range. When you use your flash normally, the light is a lot more directional as you already know. It throws in a much tighter cone.

The second thing to understanding how the Omnibounce works is to know that slapping one on does not change the SIZE of the primary light. Your primary light source (your flash gun) is still pretty much about the same size as it was.

What's critical is to understand that it's the size of the combined INCIDENT light illuminating your subject that's important here. What the Omnibounce does is that in an enclosed space, because light from the flash head now travels in many directions, the surfaces they reflect off form secondary light sources. These, combined with the light coming from your flash form a much larger incident light source than directly from the flash alone.

Hence you can imagine that if you're in a small room with a low ceiling, there are many reflective surfaces for the omnidirectional light to bounce off. When light from all these secondary sources as well as light coming directly from the flash combine together, your subject is illuminated with a light source much larger than light coming from your flash alone. Hence, the appearance of 'softer' light.

With a lesser number of, or less efficient reflective surfaces, or no reflective surfaces at all, the combined incident light 'source' becomes smaller and smaller, and hence less and less 'soft' (or harder) in appearance. For instance if you go outdoors at night to an open field and try taking the same picture, you will now discover that the light from the Omnibounced equipped flash is a lot more 'hard/harsh' since there's no nearby surfaces for the light to bounce off to 'enlarge' the light incident on your subject.

This is a rather simplistic but a pretty reasonable explanation of how the thing works.

The Lightsphere works in the exact same way, giving you omni-directional light, with one difference.

By itself, it's already a larger light source than the Omnibounce (it's bigger in size, it has more surface area). So if you compare the combined sources of light incident on your subject with an Omnibounce and then a Lightsphere, the direct light coming from the Lightsphere comes from a bigger source (more surface area) than the Omnibounce, hence the final effect looks softer. If you repeat the head and shoulder shot experiment out in the open field at night, the Lightsphere will of course give you a slightly less hard effect than the Omnibounce for this reason.

Of course the other thing is that the Lightsphere has a clever trick of allowing you to unscrew it's top (and I think a lot of users employ it this way), so that in an enclosed environment with a favorable ceiling or wall, you can create a big bounce light with direct light from the surface of the Lightsphere.

Just remember these fundamentals:

1. Think of light as 'additive'

2. Think in terms of the total amount of light incident on your subject coming from both reflected and direct sources. How 'big' or 'small' is the combined light?

Try DIYing some of these omni-directional light modifiers. One option would be large Dutch Lady UHT milk bottles. At NTUC, you can get this (with a beneficial nutrition angle - the Banana or Choc ones are yummy) as well as an accordion type water holder for water-colouring which will stretch out to be about the same size as a Lightsphere. Attach some velcro and you should be done. It wouldn't look like a well finished product of course but hey, you can save the money over buying a commercial product, to go watch War of Worlds with your girlfriend, buy popcorn, a bag of chips, drink, and maybe even a knockoff Tom Cruise t-shirt for your friend from Queensway, and still have some change left. You can also just send me a check with the balance for the lesson learnt. I am afraid I cannot accept payment in UHT milk because I am lactose intolerant.
 

#12
But whether it's Stofen's or Nikon's, I seldom find the results of the "Omnibounce" type devices good (have not tried LightSphere so I can't comment). Outdoors, well, expectedly it's harsh like what kahheng has explained. Indoors, I still find it a lot harsher than using a bounce card (which gives a bigger surface area than an Omnibounce anyway). Basically, even with the Omnibounce, despite throwing light in all directions is still a "point source". And even with it in the 45 deg angle as recommended, too much direct light from the flash reaches the subject. :( Not worth spending the $35 on. Nikon SB80DX/SB800DX users get them "free" anyway. :p

Regards
CK
 

kahheng

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Jan 20, 2002
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#13
ckiang said:
But whether it's Stofen's or Nikon's, I seldom find the results of the "Omnibounce" type devices good (have not tried LightSphere so I can't comment). Outdoors, well, expectedly it's harsh like what kahheng has explained. Indoors, I still find it a lot harsher than using a bounce card (which gives a bigger surface area than an Omnibounce anyway). Basically, even with the Omnibounce, despite throwing light in all directions is still a "point source". And even with it in the 45 deg angle as recommended, too much direct light from the flash reaches the subject. :( Not worth spending the $35 on. Nikon SB80DX/SB800DX users get them "free" anyway. :p

Regards
CK
I hardly ever use gun flashes whether hotshoe or handle mounted. But yes, like you I kinda like the light from bounce cards myself.

Vivitar once had a metal frame bounce card holder to hold a 8x10 inch card in it's catalog. This is for the 283/285 guns. It gave the nicest light I have ever seen from a hotshoe flash simply because of the rather large size of the reflective surface - it's effectively an 8x10 light source with ceiling or wall bounce light coming in as fill. Because of the design, it's extremely efficient when used with the 283 and 285. Pity it's a little unwieldy to lug around. I have even used it with an SB-25. It's stashed in storage now.

My once in a while hotshoe flash is a Braun 340SCA with a built in transparent reflector that has some silvered dots on the transparent plastic, that will give fairly nice catchlights. That's one of the best thought out built in modifier I have come across. It gives a really nice combined light.

Of all places, I bought it in Hanoi last year, stupidly thinking that I would need a flashgun on my travels. I think I have only ever used it once in anger. really should have spent the money on more booze.

I have an Omnibounce for the Nikon that I don't ever recall having used. But then again my kind of photography is usually done with light from softboxes, umbrellas or just direct with a reflector and honeycomb. I generally prefer brollies on location because they set up quick and pack up fast. A good brolly is very hard to find locally. Profotos and Balcar brollies are the best because of their accurate parabolic designs. Photoflex and Elinchrom umbrellas, of which I own more than a few, don't even come close. Sadly you don't get a wide range of Profoto or Balcar brollies here.

There's actually a very easy trick to using a hotshoe flash like an SB25 with a brolly, preferably a shoot through one. Use two very strong fat rubber bands to secure the umbrella shaft to the flash head. It's a very efficient way of position the umbrella shaft since the flash head would be pretty much in the middle of the umbrella. I call it my "$100" lighting setup. It's about $100+ when you add in the cost of small ballhead adapter to connect the flash to a lightstand, the lightstand itself, a 6 feet sync cord and the shoot through umbrella (small or medium). Assuming you own a powerful gun already of course. Beats any bounce card, omnibounce, lightsphere for do-it-yourself home portraits because of rather diffused quality of shoot through light, and the size of the light for head and shoulder shots is good. I have even used this setup professionally to good effect for a portrait on location.

The only application that I will put the Omnibounce to is when I use the SB25 with a medium softbox. The Omnibounce makes the light omnidirectional inside the box, making the light pretty even on the front surface of the box. Without it, I get a nasty blob of light in the middle. Maybe one fine day I'll actually bring this contraption out!

I don't know about the folks here but, frankly, I prefer the light from normal gun flashes to look like they've come from gun flashes, i.e., harsh, hard and very very cold. And the best one for that end is a 20 year old Metz 45CT1 that just keeps going on and on.
 

nutek

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#14
Omnibounce works best only when there are other surfaces for the light to bounce against. The OB physically increases the surface area of the light source (i.e. your flashhead) and thus allows light to be bounced from the 4 (extended) sides in addition to the primary light source from the front. Outdoors where there are no reflective surfaces to bounce against, it is practically useless.

Contrary to popular belief, it does not soften shadows *just by itself*. Shadows are softened because of the extra light that are bounced off walls / other reflective surfaces. So if you do not have walls/ceilings indoors as well, it is basically just wasting your flash power.

For the cheapest solution, I found the white bounce card method to work very well. For an expensive solution, I am also using Gary Fong's Lightsphere II, which by its design, does allow for softening of shadows even when there are no reflective walls around.

Hope this helps!
 

catchlights

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#15
Kahheng & nutek have explained in great details about how onmibounce works.

The effects are not the same between onmibounce and bounce card, onmibounce and light sphere are giving a bare light bulb effect.

This is not just about which one is better, it also about personal preference, try to understand what the effect can this device give you and it works best under what kind of situation. If you want a cheap, all round working condition (indoor and outdoor, low, high or no ceiling) and not to taxing to you flash light and batteries, use bounce card.
 

user111

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Jul 27, 2004
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#16
basicaly u get something better than nothing ;)
 

nutek

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#17
user111 said:
basicaly u get something better than nothing ;)
not necessary better :p
you could be wasting a lot of battery juice if the flash has to fire more power unnecessarily each time.
 

Nov 5, 2003
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#18
nutek said:
not necessary better :p
you could be wasting a lot of battery juice if the flash has to fire more power unnecessarily each time.
You're right abt the flash firing more power each time. It's something we take for granted. Just wondering: what else would you suggest in place of the Omnibounce?
 

Canew

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Jul 26, 2005
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#20
Hi nutek,

Can you help me by explaining why "you could be wasting a lot of battery juice if the flash has to fire more power unnecessarily each time?"

I don't undestand why the flash will consume more power with the OB on.

Thanks.
 

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