External flash setup advice

[Daymouse]

Hey guys i desperatley needs some advice on how to setup up mu external flash!

My Equipment

Canon 400D
Sigma EF - 500 DG Super Flash Unit
Sigma 24-70mm EX DG
Canon 50mm 1.8

Im fine using my camera on its own but thought i would borrow my uncles flash gun for a wedding this weekend but i cant for the life of me work out how to set up the flash gun to use on either manual, av,tv or P

Can anyone help with the settings on the above flash unit?

No matter what settings i try i cant replicate the image it gives my when its set to auto but then it doesnt capture the image in raw!

Many Thanks

 

[a1ex2001]

Thats because in auto the camera will take the flash into account when deciding the exposure, hence you can often get shots with really dark underexposed backgrounds and brightly lit subjects. When you shooting AV or in other creative zone modes the camera will expose the shot as if you had no flash attached and then assuming the flash is in Auto mode it will decide how much power to use to light up the nearest object to the camera. (Appologies for the besic explanation but it really helped me when someone put it like that)

 

[Daymouse]

Thats because in auto the camera will take the flash into account when deciding the exposure, hence you can often get shots with really dark underexposed backgrounds and brightly lit subjects. When you shooting AV or in other creative zone modes the camera will expose the shot as if you had no flash attached and then assuming the flash is in Auto mode it will decide how much power to use to light up the nearest object to the camera. (Appologies for the besic explanation but it really helped me when someone put it like that)

Thanks for that

Do you know what i need to set my camera at and what mode i need to set my flash unit too in order to achieve the same results?

The modes it gives me is

ETTL
M
Multi
ETTL (with the letters C1 on screen)
ETTL (with the letters C1 & SL on screen)
ETTL (with the letters C0 & SL on screen)


Thanks

 

[Daymouse]

Ok i think ive figured a way out now!

Got it on iso 400 set in manual, select the aperture i want and select the correct shutter speed. put the flash to ETTL the use the exposure bracketing to adjust the flash to the correct exposure!

I suppose once you have it setup your good to go for that room your taking pictures in as long as the ambient light isnt changing too much!

 

[HoppyUK]

Set camera on Av, flash on E-TTL. Camera will then balance flash exposure with ambient exposure, ie it will vary the shutter speed according to the ambient light level in the background, and vary the flash output to get the foreground exposure right.

(If the shutter speed doesn't vary with these settings, you have disabled the auto exposure function with flash. Go into the custom functions and re-enable it - see instruction booklet. Check out Flash Exposure Lock (FEL) while you're there )

 

[Daymouse]

Set camera on Av, flash on E-TTL. Camera will then balance flash exposure with ambient exposure, ie it will vary the shutter speed according to the ambient light level in the background, and vary the flash output to get the foreground exposure right.

(If the shutter speed doesn't vary with these settings, you have disabled the auto exposure function with flash. Go into the custom functions and re-enable it - see instruction booklet. Check out Flash Exposure Lock (FEL) while you're there )

Hi

Ive had a look and cant see either of these options in custom functions on my 400d!

 

[HoppyUK]

Hi

Ive had a look and cant see either of these options in custom functions on my 400d!

I also have a 350D (similar camera) and that has "Flash Sync Speed in Av Mode" custom function 3. FE lock is not a custom function, it's on the * button top right of camera.

 

[Daymouse]

I also have a 350D (similar camera) and that has "Flash Sync Speed in Av Mode" custom function 3. FE lock is not a custom function, it's on the * button top right of camera.

Ah yeah ive got that, it gives me the option of either 200 or auto! Given it a go and it seems to work just a little over exposed so just need to do some braketing to get it better

Thanks

 

[HoppyUK]

Ah yeah ive got that, it gives me the option of either 200 or auto! Given it a go and it seems to work just a little over exposed so just need to do some braketing to get it better

Thanks

Your on the way then Obviously set the CF to auto.

I'm not familar with Sigma flash but it should have a flash exposure compensation facility - turn that up/down to vary the brightness of the flash (this will override the flash compensation settings on the camera, if you have maybe set any for the on-board flash). If you're not happy with the brightness of the ambient light on the background, adjust the normal exposure compensation on the camera. Use the two controls in tandem to get the effect you want. Give it a try, turning both flash and camera compensation settings up and down to max and min. Makes a big difference - piece of cake.

The other thing to remember is using the Flash Exposure Lock - the * button. The flash exposure metering tends to be stongly influenced by what is in the centre of the frame, so when the subject is off centre, the pre-flash might read off the background and the foreground (ie your main subject) gets badly over exposed.

So when you frame up with the main subject a bit off centre, point the camera straight at the main subject and press the * button. This will fire the pre-flash and set the correct flash exposure. That flash exposure is then locked, indicated by a * in the viewfinder, and will stay locked as long as you hold first press on the shutter release.

 

[Daymouse]

Your on the way then Obviously set the CF to auto.

I'm not familar with Sigma flash but it should have a flash exposure compensation facility - turn that up/down to vary the brightness of the flash (this will override the flash compensation settings on the camera, if you have maybe set any for the on-board flash). If you're not happy with the brightness of the ambient light on the background, adjust the normal exposure compensation on the camera. Use the two controls in tandem to get the effect you want. Give it a try, turning both flash and camera compensation settings up and down to max and min. Makes a big difference - piece of cake.

The other thing to remember is using the Flash Exposure Lock - the * button. The flash exposure metering tends to be stongly influenced by what is in the centre of the frame, so when the subject is off centre, the pre-flash might read off the background and the foreground (ie your main subject) gets badly over exposed.

So when you frame up with the main subject a bit off centre, point the camera straight at the main subject and press the * button. This will fire the pre-flash and set the correct flash exposure. That flash exposure is then locked, indicated by a * in the viewfinder, and will stay locked as long as you hold first press on the shutter release.

Many Thanks for your help and advice matey