Sanity check - outdoor flash scenarios

[duncan_trebilcock]

Hi all,

 

I hope you will forgive these rudimentary questions.

 

I have a wedding this saturday, where I will be doubling the group

shots. I have shot exclusively black and white natural light for a

long time now, and it's a while since I have shot flash. I am putting

together procedure lists so I don't make mistakes, since it is going

to be very hot and humid. I don't get on well with humidity.

 

These are my scenarios.

 

I have a metz ct1 and will be shooting nps 160 on a tripod. The photos

will be taken at around 3pm

 

Direct sun has been ruled out, since it will in my opinion be to

bright for people to maintain natural expresions.

 

 

1. Pose group under the shade of a tree with church in full sun in the

background.

 

Expose for the background and set the flash to the same aperture to

equal the light levels in direct light, which is likely to be 3-4

stops brighter than shade.

Use guide numbers to calculate flash distance at full power. (I don't

trust the autothyristor with regions of extreme brightness in the

scene.)

Position flash off to one side coming - The same side as the sun, to

give a little modelling.

 

2. Sun behind.

 

Judgement call here, I will need to see what this does to hairstyles -

e.g. flyaway/ thinning hair.

 

Expose for ambient light, and set flash distance as per guide number

for that aperture. Flash will be key light here as well. Perhaps

underexpose the background by a little to bring out the group.

 

3. Open shade at rear of church.

 

Expose for ambient, and use flash on auto set to -1(e.g is correct

aperture is f8, set flash to f5.6.

 

Sorry about the basic questions. I was just hoping someone could do a

sanity check on my procedures here.

 

Regards

D.T.

[alan_chan4]

I would probably use "GN x 2 = distance x aperture" (or "GN x 1.4 = distance x aperture") for scenarios 1 & 2. The subjects would probably look too harsh by using the straight "GN = distance x aperture" formula.

[scott levine]

Line up your group, and find the brightest area and meter it. I would use that as your

reference point and set your flash one stop over. If the ambient light is f5.6, I would set

your strobe for an output of f8.0. This will ensure that the faces are clean and your

background will be slightly saturated. Also, if your not comfortable using flash, make sure

that your shutter speed is set properly!!!

[picturesque]

Depends how you like to balance the flash with the ambient.

 

1. Even though the light differences may be 4 stops, remember that there is still some light in the shaded area, so filling completely to the level of the bright sunlit background may not need as much flash light as one would calculate. In my experience, doing so on negative film causes overexposure of the subjects and underexposure of the background, causing the background (sunlit church) to go darker, sometimes to the point of looking unnatural.

 

2. Same for this lighting situation. Depends on how much of the subject is lit by the sunlight. If only the hair, you can afford to overexpose the hair (halo effects can be quite nice) and expose for more of the shaded side. If some part of the face is lit by the sunlight, you have to expose more for the sunlight and fill more.

 

3. For completely even shade, I find -2 stops fill is enough. -1 is a bit "flashy" for me.

[stevensimages]

Nadine is correct. Please ignore anyone who tell you to set fill flash at a higher setting than the ambient light. It doesn't matter whether they are in shade or direct sunlight. Outdoor flash should only be to fill in shadows subtly. Otherwise, you lose the natural quality of the outdoor light and you may as well shoot everything indoors. Also, if you don't have a meter, get one. Incident readings are much more valuable than reflected in most cases. A little Polaris will cost you a bit over a hundred dollars and will so everything you need to do in almost any normal situation.

[think27]

Also agree with Nadine... The only time I'll put the flash higher than the f-stop is for a sunset shot for a rich and saturated background.

[steve_levine]

""it's a while since I have shot flash.""

 

 

Shoot a test roll!!!

[timcorridan]

listen to nadine. she gave me sunset advice that was right on.