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mercho
05-08-2009, 8:51pm
Hey Guys,

I have bought a wireless flash trigger set for my 430ex, and i cant seem to get a decent shot with them.. are there any tips or hints for getting the exposure and flash metering correct?

I have tried a few shots tonight of my bike and the flash seems to overpower the shot, or isn't enough... Would the fact that its dark outside have much to do with it? :confused013

Thanks for any help in advance :o

DAdeGroot
05-08-2009, 8:57pm
Have you read through the strobist.com site ?

Do you have a copy of Light, Science and Magic ?

If not, I'd advice you read both.

However, there are several things you can learn straight up that will make a big difference.

Distance matters. Distance from you to the subject, distance from the subject to the background and distance from the flash to the subject and the background. All of these change how effective the flash is.

Also, Aperture. This controls how much flash exposure you have. Shutter speed and aperture combined control the ambient light. You can mix and match to suit your needs.

Direct flash (pointed right at your subject) usually sucks (unless you're doing funky things with hard light). Either bounce it, or better still use a modifier like an umbrella, softbox, diffusion panel, etc.

Oh, and always shoot in Manual and have the flash in manual too!

Basic setting to try out on a person - f/5.6, 1/200th, iso 100, flash at 1/4 power through a shoot-through umbrella or diffusion panel about 1.5m away from the subject at about a 45 degree angle. Give it a whirl, and adjust aperture up or down as required - watch your histogram!

bigdazzler
06-08-2009, 2:04am
A couple of things that are very important to know Brad.

1. Your max flash sync speed. This is the fastest shutter speed youll be able to shoot at when using the flash in manual mode with triggers.

EDIT: 1/200th is the x-sync speed on your camera, so dont go beyond that. And as Dave said above, learn to use your histogram .. it will be a godsend when chimping.

2. EVERYTHING is manual when using triggers. No TTL metering at all. So if you dont have a meter, a lot will depend on trial and error.

Definitely have a close look at Lighting 101 on www.strobist.com .. that should get you started :th3:

mercho
06-08-2009, 9:06am
Thanks for the help guys!

Ill check out that site in more detail tonight, and see if i can grab a copy of that book..

Might have another crack this arvo

MarkChap
06-08-2009, 10:33am
Brad don't know if you are aware of the formula for manual flash

430 EXII has a guide number of 43 mt at 105mm zoom and 100 ISO (don't forget to check your manual for the guide number at lower zoom settings)

Aperture = Guide Number divided by distance (to subject)
Therefore
Aperture = 43 / distance (lets say 10 mt )
Aperture = 43 / 10
Aperture = f4.3 (so f4)
Distance = Guide number divided by aperture
Therefore
Distance = 43 / aperture (lets say f8)
Distance = 43 / 8
Distance = 5.3 metres from your subject

Every step down in power on the flash is 1 stop less light -
1/1 (full power)-> 1/2 = 1 stop
1/2 -> 1/4 = 1 stop.

Modifiers - umbrellas, bounce, stofen, gary fong etc all take away an amount of light that you then need to allow for with either distance or aperture.

Have fun learning, I know I am

mercho
06-08-2009, 11:06am
Brad don't know if you are aware of the formula for manual flash

430 EXII has a guide number of 43 mt at 105mm zoom and 100 ISO (don't forget to check your manual for the guide number at lower zoom settings)

Aperture = Guide Number divided by distance (to subject)
Therefore
Aperture = 43 / distance (lets say 10 mt )
Aperture = 43 / 10
Aperture = f4.3 (so f4)
Distance = Guide number divided by aperture
Therefore
Distance = 43 / aperture (lets say f8)
Distance = 43 / 8
Distance = 5.3 metres from your subject

Every step down in power on the flash is 1 stop less light -
1/1 (full power)-> 1/2 = 1 stop
1/2 -> 1/4 = 1 stop.

Modifiers - umbrellas, bounce, stofen, gary fong etc all take away an amount of light that you then need to allow for with either distance or aperture.

Have fun learning, I know I am

Thanks for that mark!! Ill read the manual when i get home and try this out :)

ehor
06-08-2009, 4:52pm
I go by
Appeture = flash light control
Shutter speed = ambient light control

jev
07-08-2009, 4:03am
Don't forget ISO...

Using ISO 400 = 2 stops gain from ISO 100 => doubles the flash guide number.

mercho
10-08-2009, 6:55am
Cheers thanks guys, ill try this out over the next week or so, didn't get a chance on the weekend :)