Flash modifiers

[Bobobird]

There is a vast range of products that attach to flash units such as domes, half-domes, bounce cards, grids, gels, snoots, etc.

I understand generally what each does but one eludes me - the clear dome.

What is the purpose of a clear dome? How and why would one be used?

Does anyone have some sample shots to share (or links to web shots)?

Thanks.

[Andrew76]

Bobo, I think its primary purpose is to relieve your wallet of another $100 or so.

But seriously, I am sorry, I don't know. I don't own one, and have never used one. I was just trying to be funny.

[Bobobird]

Haha, this is expected of Canadians.

[Ken MT]

To be used in wet weather to keep the rain off the flash, I expect

[rpcrowe]

Basically, the principle of a clear dome is that with the dome attached, the flash acts somewhat like a bare-bulb flash tube with light coming from all directions and bouncing off every surface to provide very soft lighting.

While I like bare-bulb flash (I had a SunPak 120J from which you could remove the reflector changing it into a bare-bulb flash that provided very soft and even lighting) I think that the domes for standard hotshoe flash units are pretty wasteful of light and mainly cut the power of your flash without producing the wonderful effects of a bare-bulb flash.

Acyually, I have a Stofen diffuser but, I normally use it as a case in which to store my AA batteries...

My favorite flash modifier is the Joe Demb Flash Diffuser Pro (www.dembflashproducts.com) because of its great light and its flexibility...

[Bobobird]

Ken - a flash raincoat might be better.

Thanks Richard. Makes sense. I was not clear why one would want a clear dome.

[Colin Southern]

Hi Bobo,

I think that when some people hear of flash diffusers they think that it's the device mounted on the flash doing the diffusion, but it's not ... in the case of clear domes they just spread the light all around the room and THAT is what diffuses the light. IN the case of the Lightspheres they also allow for a direct portion of flash to illuminate the frontal plane a bit more (and give nice catch lights).

[xpatUSA]

This thread is a little confusing to me, sorry. While I'm OK with diffusers per se (Lambert, et al) I'm not getting how a clear dome does anything more than keep the rain off, as mentioned earlier. If the dome is truly clear and has no micro-lenses on it, how does it spread the light any more than an angled piece of glass, e.g.? Is it internal reflections? Are the different curvatures of the inside and outside significant?

Help!

[GrahamH]

Nice explanation Colin.
I see so many photographers using the diffusers outside (at weddings or events), or in such a large building that there is no effective return of light.
I was at an outdoor function last week. Great props all around (cars, various watercraft, planes, helicopters and bikes) and so many event photographers using the various diffusers on camera.
I haven't done the math to figure out the max softening of the light (penumbra), but I already know that a point source of light versus a diffuser from a range of 8-10' isn't going to be visible.
Even worse, 20' away there were white marquee tents. So there was a top and sides that could have been used to reflect light from.
I think the main use of these gadgets is so the photographer can parade around with the cache of 'being a professional'.
All show and no substance. At least it allows the opportunity for others who know how to use light better to shine like a beacon .
Graham
(still lots to learn about light)

[Bobobird]

Thanks guys. To be clear I should have mentioned clear = almost transparent/foggy.

Graham - blame Strobist for all that.

[Colin Southern]

This thread is a little confusing to me, sorry. While I'm OK with diffusers per se (Lambert, et al) I'm not getting how a clear dome does anything more than keep the rain off, as mentioned earlier. If the dome is truly clear and has no micro-lenses on it, how does it spread the light any more than an angled piece of glass, e.g.? Is it internal reflections? Are the different curvatures of the inside and outside significant?

Help!

Think of it like this ...

If you don't have any kind of flash modifier then the light will only travel in the direction the flash is pointed; you could stand behind the flash or to it's side and not see it's full brightness. With a dome diffuser like the Lightspheres you'll see the light from 360 degrees around the diffuser, and it'll be of equal intensity.

That light then radiates to the surrounding walls, and is bounced back.

[Colin Southern]

Nice explanation Colin.
I see so many photographers using the diffusers outside (at weddings or events), or in such a large building that there is no effective return of light.

A lot of them make be laugh when I see that

Essentially, the softness of the light is a function of it's effective size - THAT'S IT! A normal flash head is probably around 2 square inches ... but with a stofen like "diffuser" you end up (in a non-bounce situation) you end up with ... about two square inches. They don't do anything.

Contrast that with the increase in area from bouncing it into a shoot-through umbrella that's relatively close (I'll let someone else do the area maths) ... MASSIVE difference in light quality.

[RustBeltRaw]

Essentially, the softness of the light is a function of it's effective size - THAT'S IT! A normal flash head is probably around 2 square inches ... but with a stofen like "diffuser" you end up (in a non-bounce situation) you end up with ... about two square inches. They don't do anything.

Pardon me for intruding, Colin, but I believe you're oversimplifying a bit. Assume your flash is on TTL with no compensation, and you take the same shot with and without a Stofen or similar frosted bulb diffuser. Without, you'll wind up with much harder shadows and much more light on your subject. Adding the frosted bulb will reduce the amount of light hitting your subject, much like setting the flash to -1 or -2EV on TTL, and soften the shadow by throwing some light to the sides to reflect and fill the shadow. So you're correct in that they do not really create a larger source, but they do make it much less obvious that you used flash. Whether or not that's the same thing as "softening" in a strictly technical sense is debatable, but the effects are definitely similar.

[kdoc856]

I have used the Stofen Omni-bounce a little. Didnt take long to realize you lose about 4 stops of light, requires about 4-5 times as long for your battery to recharge, and obviously the commensurate eating up of your flash batteries.

I have used it a little in my daughter's living room chasing our grandchild around, and the light was clearly less directional, shadowy and harsh than a directed flash., but would not try it on a more serious shot or more than about 5 feet away .

I've been happier using a RogueBender (mostly a flexible white card) and pointing my flash straight up into it. It's similar to the Joe Demb diffuser that Richard uses.

[Colin Southern]

Pardon me for intruding, Colin, but I believe you're oversimplifying a bit. Assume your flash is on TTL with no compensation, and you take the same shot with and without a Stofen or similar frosted bulb diffuser. Without, you'll wind up with much harder shadows and much more light on your subject. Adding the frosted bulb will reduce the amount of light hitting your subject, much like setting the flash to -1 or -2EV on TTL, and soften the shadow by throwing some light to the sides to reflect and fill the shadow. So you're correct in that they do not really create a larger source, but they do make it much less obvious that you used flash. Whether or not that's the same thing as "softening" in a strictly technical sense is debatable, but the effects are definitely similar.

Hi Lex,

I think you missed the bit in my post where I said "in a non-bounce situation" (eg out doors).

But regardless, if a Stofen-equipped diffused is pointed at the subject - and you're in an ETTL mode - then you'll end up with pretty much the same degree of light hitting the subject. The camera doesn't know there is a diffuser attached so the pre-flash is attenuated by the same amount, and the camera will simply increase flash power output (assuming sufficient available) to compensate for the attenuation.

[RustBeltRaw]

Hi Lex,

I think you missed the bit in my post where I said "in a non-bounce situation" (eg out doors).

But regardless, if a Stofen-equipped diffused is pointed at the subject - and you're in an ETTL mode - then you'll end up with pretty much the same degree of light hitting the subject. The camera doesn't know there is a diffuser attached so the pre-flash is attenuated by the same amount, and the camera will simply increase flash power output (assuming sufficient available) to compensate for the attenuation.

You're right, I should have read more closely. I posted that on the basis of some experience from just last night where I was switching between a frosted bulb and a naked flash. Apparently my conclusions, and understanding of TTL functions, were incorrect. Still learning.

[rpcrowe]

I have a home fabricated flash bracket on which I used to mount a twin-lens reflex. The there is an elevated bar which is about two feet long (~2/3 meter). There is a mount on this elevated arm on which I fastened a SunPak 120J.

Indoors with ceilings/walls to reflect the light, I used the bare-bulb 120J without a modifier and with the bare-bulb facing up. This provided very diffused and soft lighting since every surface in the room became a reflector.

Outdoors, I used a Lumiquest Mini Softbox over the bare-bulb which was pointing forward. This provided more directional light but, the light was still soft. A softbox over a bare bulb is far more efficient in providing soft light than trying with a tiny hotshoe flash reflector.

This rig worked quite well but in actuality, I get almost (I haven't tested the units side by side) as good lighting with my 550EX flash on a stroboframe camera-flip bracket. I point the flash directly up when there is a ceiling off which to bounce and have the Big FlipIt portion of a Joe Demb Flash Diffuser Pro straight up to cast some light forward filling shadows. Outside or inside when the ceiling is too high or too dark off which to bounce, I place the Big FlipIt portion of the Demb Flash Difuser pro at about a 45 dgree angle forward. This sends a goodly portion of the light forward but is still soft.

At times, I will attach an 8x10 inch foam board to the FlipIt which will provide even softer light. I can place a green or amber filter over the flash head to use to match the color temperature when I am shooting in either fluorescent or tungsten ambient light. If I am shooting outdoors in the magic hour with the setting sun illuminating my subject. I will put the amber filter over the flash tube...

In actuality, I have used the fabricated flash bracket with an old Honeywell Strobonar (potato masher - that's how old the bracket is)) unit firing directly back into the umbrella. I could easily, if I desired mount a Canon 550EX flash unit firing back into the umbrella and use my pop-up flash to fire the 550EX (on slave) and also to provide some fill light. This would "almost" provide butterfly lighting. Indoors, the pop up flash would trigger the 550EX above, Outside, I am not sure that it would work.

I will find the old bracket. It is stored in my RV garage - I never throw away any photo equipment) and shoot a picture of it.

I have not used the fabricated bracket because I cannot tilt the camera into the vertical position using this bracket. This was no problem with a 6x6 cm twin-lens reflex. However, thinking about this, I could use my 70-200mm f/4L IS and mount it on the bracket using the tripod ring. Tilting the camera from vertical to horizontal would be no problem. It might be fun to experiment with...

[Colin Southern]

You're right, I should have read more closely. I posted that on the basis of some experience from just last night where I was switching between a frosted bulb and a naked flash. Apparently my conclusions, and understanding of TTL functions, were incorrect. Still learning.

No worries Lex

You have to get up pretty early to catch me out on flash questions - I kinda live/breath the stuff

[RustBeltRaw]

No worries Lex

You have to get up pretty early to catch me out on flash questions - I kinda live/breath the stuff

So it seems. I'm trying to master it, but holy crap, there's a lot of material. Found light will always be simpler, but for my work, flash is practically a necessity. Always glad to get edumacated.

[Colin Southern]

So it seems. I'm trying to master it, but holy crap, there's a lot of material. Found light will always be simpler, but for my work, flash is practically a necessity. Always glad to get edumacated.

I use flash 100% of the time for portraiture - inside and out. Natural light sucks! (stands back with marshmellows at the ready!). In all seriousness, outside, natural light is of course a great starting point, but you just can't rely on it to get you the shot you need 100% of the time -- and for that, nothing beats a couple of soft boxes with some off-camera flashes inside.

The learning curve does seem a little steep to start with, but it all makes sense after a short time -- so long as you stay current with it.