Bounce Flash drains Batteries faster: True or False?

[bambam_ilusorio]

I frequently find articles here and other fora advising to bounce your flash on walls, cards, etc. to

soften/diffuse the light from it, but recently I increasingly come across warnings that bouncing---and now using

diffusers such as a demb or stofen--- eat a lot of "battery juice." Is this based on fact? Those warnings never

come with explanations as to why though...If true, is there a science to it why it works this way, and just how

much is the battery drain compared to not bouncing?

[stacyalberto]

the only reason it would do that is if you use your flash on high power to compensate for the diffusion.

 

i use a diffuser and my batteries last just fine.

[garrison_k.]

"Is this based on fact? "

 

It's based on physics. Which method do you think requires the most power, direct flash or in-direct flash? With

direct flash, your subject may only be 10 feet away, but if you bounce up the ceiling and back down to your

subject, the flash

could have three times the distance to throw the same light. Which do you think takes more power, a subject at 10

ft or a subject at 30ft? Using more power means more battery consumption,

obviously.

[conraderb]

of course bouncing means larger drain, b/c the bounce always means lighting up more.

 

basic physics. every time you double the distance between flash and subject, you are trying to light up 4x the area.

 

direct flash illuminates what is in front of the camera. simple.

 

bounce flash illuminates a ceiling or a wall, and then whatever bounces off the ceiling or wall hits the subject. the flash is usually having to put out at least a stop more light (in a very, very small room, say), or in a large room, easily 5 to 8 stops more light.

 

it is sort of like trying to put out a delicate flower that is on fire: can you spray high pressure water on it directly, which will work, but it will hurt the flower (make your subjects look terrible). or you can direct high pressure water to the ceilings and walls and let it drip down, resulting in a moist flower and happy subjects.

[bambam_ilusorio]

Of course its physics, and I get that part. What I was wondering about was if by the mere act of bouncing/diffusing, without any other changes to the variables such as increasing power, was draining batteries faster, because there was some sensor in the flash that automatically escalates this to compensate for the fall-off. It turns out, as do many other advices on the web, that this caveat is made in general terms, and rather left to the reader's interpretation.

 

Thanks for your immediate responses everyone.

[cjogo]

TRUE --- If I was to shoot direct flash > on a subject --which required 5.0 to be correctly exposed.....that same shot, would probably require, nearly 9.0 or a plus 1 1/2 :: to bounce the flash and receive the same correct exposure >> call it physics........it drains batteries.

[john fleshin]

Depends, on whether your flash unit pumps up the output to adjust for the distances, and how it is set.

 

If your flash is auto, and you put your hand over the tube, or shoot at the night sky, or cover the sensor, you will

entirely dump the capacitors, which will have to charge. Careful you do not burn yourself, or reflect too much heat

back in to the unit.

 

If the flash is on manual, probably no difference.

 

At the shop a guy fired his flash against the display case, and it cracked.

[William Michael]

> What I was wondering about was if by the mere act of bouncing/diffusing, without any other changes to the variables such as increasing power, was draining batteries faster, because there was some sensor in the flash that automatically escalates this to compensate for the fall-off. <

 

YES:

 

If the Flash is being used in an AUTOMATIC mode there is a sensor (somewhere, not necessarily in the flash) which will increase the power to compensate for the light fall off caused by the bounce. The batteries will be used more quickly, as a result of bouncing.

 

NO:

 

If the flash is entirely in MANUAL MODE you can bounce it all you please and it will put out the same power, for that particular manual setting, no matter where you point it. The batteries will be used just as quickly (or slowly) if you bounce, or not.

 

WW

[rainer_t]

W.W. -- "and it will put out the same power" (in the NO paragraph)

 

I would like to add to that, "but while the flash outputs the same amount of power/light it doesn't light up your subject as much as the direct flash does with the same setting".

[vrankin]

TRUE- at every increase of distance by a factor of 1.4 you must increase the exposure by one stop (double it) to maintain

the same reflectance back to the camera from the subject (every manual flash chart supports this fact). Bouncing

increases the distance to your subject. Diffusion of the light over the bounce surface probably subtracts more light as well.

[Ed_Ingold]

Unless you are working (literally) in the dark ages, your flash/camera has some TTL capability. Bouncing the flash takes more power (at the same aperture) to light the subject - perhaps a stop or two more power. Consequently, the batteries won't last as long. Using a Sto-Fens or Nikon diffusion cap has about the same effect as bouncing.

 

If the flash power is fixed, then bouncing the flash makes no difference - but you have to open the aperture more.

 

Bounce (or diffused) flash makes better pictures, so it's worth while regardless of the cost in power. If battery consumption is an issue, then use an external, high voltage battery like a Quantum Turbo, to power the flash. I get at least 400 full pops from a Nikon SB-800 and a Turbo 2*2, and always use the diffusion cap. Always keep several sets of AA batteries handy (or whatever your unit requires).

[William Michael]

@ Rainer T:

 

Yes. Thanks.

 

Your expansion is very valuable to inform and give the full picture (pun intended).

 

Considering what I think was a misunderstood question, your addition is both noted and appreciated.

 

Thank you,

 

WW

[ujwal]

True.

(provided you are expecting same exposure)

 

"Using a Sto-Fens or Nikon diffusion cap has about the same effect as bouncing." I'm afraid its not true at all.

Diffusion caps...allows flashgun to act like a bare bulb.

 

Bouncing up or behind or on the side wall.......makes the wall act like a giant soft box, which give far better and softer light and at the same time lights the foreground and background much nicely.

[steve_hovland]

Yes, but it's worth it for light quality indoors.

 

I often shoot at ISO800 and f4-f5.6 indoors, so I don't worry about it that much.

 

A Stofen soaks up about 2 stops, so I use mine to hold small parts, not on my flash...

 

I use a white card on the back of the flash to throw some light forward. My current version is a piece of 1/8 foamcore with a small piece glued to one end to wedge the card forward to pick up more light.

 

Outdoors I will shoot direct flash, sometimes with Rosco Tough Frost over the front- only soaks up 1 stop. The wide angle diffuser built into some units may also smooth out the light.<div></div>

[steve_c.5]

Many flashes, like mine, have an internal sensor so they know when the flash head is aimed upward rather than straight ahead, and adjust flash power accordingly when in TTL mode. However, you will find that if you manage your camera settings manually, raise your ISO to 800 or more indoors, and control flash output manually, you can drag the shutter, get better shots, and use WAY less flash power.

 

When I shoot in Program mode with the flash in TTL, I go through several sets of batteries at a wedding. When I shoot manual and keep flash output between 1/8 and 1/2 power, I can shoot a whole wedding on a couple of sets of batteries (2600 MaH Nickel-Metal Hydrides). I also use an auxilliary battery pack to keep the flash juiced up.

[think27]

MODERATOR NOTE:

 

Steve - Please only upload images at 700 pixels or less AND please put a caption in the caption box. We do not want links that take you to another window in order to see it in the Wedding Forum.

[garrison_k.]

"What I was wondering about was if by the mere act of bouncing/diffusing, without any other changes to the

variables such as increasing power, was draining batteries faster, because there was some sensor in the flash

that automatically escalates this to compensate for the fall-off."

 

Automatically escalates...what? I have no idea what you are trying to get at. And sounds different than your

original question (I increasingly

come across warnings that bouncing---and now using diffusers such as a demb or stofen--- eat a lot of "battery

juice.)

 

All modern flashes operated on ttl or auto thyristor will pump out the light it needs for what it feels is a correct

exposure. If you put anything in front of your flash (diffuser) it will take more power than a bare head to

achieve the same light. If you aim your flash up, sideways, or at your face, the flash will also require more

power than otherwise being directly pointed at your subject. Flashes only 'eat the juice' they need to make the

power they need. If you put obstacles in front of the head (diffusion) or give the path to your subject a

longer route (bounce) of course you'll use more power and 'eat more juice'.

[dave_hoffmann]

Using a diffuser or bouncing does not in itself take more "juice". You can shoot direct at 1/4 power or bounce/diffuse at 1/4 power and the flash will use the exact same amout of battery power.

<p>

However, to expose your subject properly, the flash will need to pump out more power when bouncing compared to direct.

<p>

<i>Steve: Outdoors I will shoot direct flash, sometimes with Rosco Tough Frost over the front- only soaks up 1 stop. The wide angle diffuser built into some units may also smooth out the light.</i>

<p>

Sticking plastic (omni-bounce) or a rosco gel will not soften (or smooth light). Softness is created by a larger light source. Outdoors, there is nothing to bounce off to create a larger source.

[bruce_stenman1]

At ISO 400 it was a bit of a concern. With most cameras able to provide usable images at ISO 1600 the flash output is reduced by 75% and battery life is not a problem. I can shoot an entire wedding with one set of AA's in the flash and in the battery pack and have sub-second recycle times even in burst mode with the D3.

 

The flash should be to provide fill and not to be a substitute for the available light (which means any light that is available).

[steve_c.5]

(for Dave Hoffman) You're absolutely correct. One thing I use when shooting outdoors at night is the Gary Fong Lightsphere with the white dome in place. This allows the flash to bounce off the upper dome (some light gets thru but not that much) and the rest is diffused 360. This makes a softer source of illumination in indoor locations with black or dark ceilings, or outside at night. I often take the flash off the camera and connect with a sync cord, and hold the flash off to the side to add modeling.

 

Alternately, you could use David Ziser's technique and use the flash wireless off-camera with a shoot-thru umbrella. This will really broaden the light source, but you would probably need an assistant to hold the rig on a monopod, as he does.

 

If you simply point the flash head at your subject in the dark, you'll get redeye most likely unless you use a redeye setting to get the pupils to iris-down. And, the lighting will look pretty flat that way.