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Outdoor flash


bill_heiker

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It has always been my understanding that when doing outdoor fill

flash, you meter the scene and then set the flash for 1 to 2 stops

less output. In other words, if you meter the scene at f8 and 1/125,

then by setting the flash at f5.6 or f4, the shadows should fill

nicely, but not completely. Well, I tried this today. The camera

indicated an ambient exposure of F11 and 1/250 second. With that as

a starting point, I took pictures with flash settings from f5.6 up to

f22 in one stop increments. When the processed prints came back,

every print was EXACTLY the same, both the foreground and the

background was exposed the same in all pictures. In every picture,

the foreground (a picture of me) was overexposed while the background

(a house across the street) was correctly exposed. The flash works

just fine with my indoor shots and the lab that does my processing

tells me that my negatives are consistently properly exposed. Does

anyone have any idea what is the problem with my efforts to do

outdoor fill flash?

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You didn`t tell what shutter speed you used.You will need to meter the exposure at the same shutter speed as you flash syc. speed to get the correct exposure.Example if you meter at F8 at 125 sec and shoot at F8 and 60th of a second you are getting more ambient light on your shot.

I shoot with a hassey that way I can use flash at all shutter speeds outside.I meter ambient light and then take a flash reading. If I get F8 at 250 0f a second I set the flash for F8 and shoot at 250 of a second. If you want more fill then set the flash for F16 etc.

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How were you metering the flash? If you were using some

kind of auto setting, are you sure the flash had enough

power? If you're shooting a person against a distant background,

that background will soak up a lot of light, and my guess is

that the flash was putting out all of its available power on

every shot.

<p>

With a small nearby subject against a distant background, it's

usually most reliable to switch the flash to manual. Either

meter it with a flash meter or use the calculator on the

back of the flash (or the GN method if the flash lacks any

sort of calculator).

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are reasoning in the reverse order?

 

"meter the scene and then set the flash for 1 to 2 stops less output. In other words, if you meter the scene at f8 and 1/125, then by setting the flash at f5.6 or f4"--> f11 or f16?

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Bill,

 

Your methodology should work perfectly if you are metering with a handheld flash

meter.

 

If the ambient exposure is 1/125 @ f8 and your flash meter reads f4 or f5.6 when

you pop the flash, your fill flash will not be overpowering.

 

I have had little luck using this technique with automatic flash. I have also on

occasion had problems using this technique with advanced TTL Flash.

 

But you know, it ALWAYS works when using my handheld flash meter.

 

Don't forget to balance the color temperature of your flash with your ambient color

temperature. Nothing screams fill flash louder than a subject lit by blue colored

strobe light.

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the poto shop balanced the shots for you so they would come out.. some good equipment does this automatically.. almost all cameras are auto exposed from in camera meter which is only correct in few situations, so negs have a wide latitude to make ametures happy.. use slide film for this kind of tests.and tell developer not to do any adjusting and to use new or properly updated chemicals. .. when using one flash ( i use ambinet light for fill when in shade or clowdy days) measure the light at the subject about one stop over ambient light. if using two flashes use one flash to one side a little over ambient, other side one stop over, third flash would be on back ground one stop over.. then take reading at subeject with all flashes going.. and shoot that.. a good flash meter is more accurate than your cammera so if problems arise i would suspect the camera before the metering.. a great flash for this type of work in ameture setups is a viviter 283 with a vp-1 varipower attachment.. its adjustable in very light amounts of flash, not several settings like most flashes. i use a luna star f gossen meter..and its available used... its awsome.. good luck dave..
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Bill you sound confused.How did you alter the flashes output?Was this all done on AUTO?Were you shooting in bright sun and trying to fill those shadows?Without seeing your film & prints,it is hard to say,but it sounds like you fired way too much flash over exposing the subject.The lab should always try to print for the flesh,not the background.(find another lab)Often outdoor flash shots exposed this way will have correct skin exposure,but the background will look like a nuclear bomb is exploding.
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The first issue is to do this test with transparency film, as suggested. I suspect there is some auto-correction being done by the lab. Alternately, ask for a contact sheet, rather than proof prints from print film, and that cuts out that problem. You could take the negs to a lab and get contacts from the roll you shot, and you might learn more.

 

The other issue is whether you are using auto flash of some sort. The flash should be set for manual, so that you can regulate the output consistently. If ambient was f:11 and the flash is set on manual, and the flash is set for an exposure of f:5.6 at the flash-to-subject distance you were using for the film speed you were using, then you should see a very slight fill effect, if any effect at all. The f:8 setting should give you something more natural; f:11 should look like obvious fill flash; and f:16 and f:22 (if the flash is powerful enough to produce that much output at the distance and film speed indicated) will look overexposed. You should also do an exposure with the flash off, just to see the difference between no fill and the minimal fill setting.

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I note some people are mentioning lab auto corrections.

Note on careful reading that Bill describes

taking <b>every</b> shot with the camera set

at 1/250@f/11. All he's trying to change

is the flash power. If the flash power is indeed changing,

the ratio between flash and ambient will change, and

regardless of auto lab compensation, the photos will

look somewhat different, as the light balance changes

between foreground and background.

<p>

That's why I'm guessing that the flash power didn't

really change. And the most likely reason I can think of

for that is an auto flash running out of power and

dumping full output on each shot.

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Due to the inherent fall-off in light with distance with flash, you will not get a good result with a light subject in the forground, unless you use additional flash or bounce to light up the background.

 

Try a coloured model, with a white house as background.

 

The purpose of fill-flash in bright sunlight is to reduce contrast by filling shadows - so the foreground test subject should be three-dimentional, with shadows to fill, not a 2d picture.

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Bill

 

While I do not disagree with the method you have chosen, (i.e. meter the scene and set the flash for 1 or two stops less than ambient exposure) I disagree that this is the only method. I have had fantastic success in using my flash as the main light and the ambient light as the fill light in outdoor portraiture. You will need an accurate light meter that also measures flash exposure. and you will need to have your flash off camera. try it sometime.

 

Kevin

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