420 EX not working ?

My 420 EX is playing up. Even though the flash goes off it doesn't seem to make any difference to the lighting of the scene.

For example in manual mode with my 40D and 70-200 2.8. I get the same histogram with and without flash (scene at 2m from the camera).

More details : -

The camera says the flash has fired
Zoom lights on the flash change when I go from 70mm to 105mm
FEC is at +0, changing even up to +2 makes no difference
With or without hispeed sync same results
shutter speeds slower than 1/250 sec same results
Tried with my sigma 17-70 and canon 50mm same thing


Any help? Or is it time for a 580 EX?

cheers
Ali

Do you have any sample images we can take a look at?
Was the flash pointed straight ahead?
Try taking a picture of yourself in front of the mirror in a darkened room or bathroom. Does the picture show the flash firing?

PacAce wrote in post #8647874
Do you have any sample images we can take a look at?
Was the flash pointed straight ahead?
Try taking a picture of yourself in front of the mirror in a darkened room or bathroom. Does the picture show the flash firing?

Will put up a couple of shots. Tried the mirror and no sign of the flash firing in the photo even though I could see the flash firing through the viewfinder

cheers
Ali

alistairksmith wrote in post #8648411
Will put up a couple of shots. Tried the mirror and no sign of the flash firing in the photo even though I could see the flash firing through the viewfinder

cheers
Ali

If you can see the flash firing in the viewfinder then you flash isn't syncing or your only getting pre flash

Mirror shot in a light room and a dark room

cheers
Ali

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And the same shot taken with and without flash

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Yup, there's somethng definitely wrong with your flash. The 420EX is a very simple flash so it's not a setting or configuration issue. Time to either send the 420EX in for servicing or buy a new one.

BTW, there is one other thing you can check, though. Check to make sure that your 40D is not set to "not fire" the flash (see page 103 in your 40D manual).

You are going to love your new flash!

PacAce wrote in post #8649268
Yup, there's somethng definitely wrong with your flash. The 420EX is a very simple flash so it's not a setting or configuration issue. Time to either send the 420EX in for servicing or buy a new one.

BTW, there is one other thing you can check, though. Check to make sure that your 40D is not set to "not fire" the flash (see page 103 in your 40D manual).

Flash is deffo firing when I presh the shutter. Just not at the right time.

cheers
Ali

Titus213 wrote in post #8649860
You are going to love your new flash!

Was hoping to have the 420EX to use as a slave when I eventually got a 580 though.

cheers
Ali

alistairksmith wrote in post #8650859
Flash is deffo firing when I presh the shutter. Just not at the right time.

cheers
Ali

I don't think the main flash is firing at all. What you're seeing is the preflash that's fired before the shutters open.

Mine has been doing the same thing. Sent mine in to a local repair shop will let you know what I hear.

PacAce wrote in post #8651040
I don't think the main flash is firing at all. What you're seeing is the preflash that's fired before the shutters open.

Why a preflash? Didnt know that would happen other than for focusing.

cheers
Ali

alistairksmith wrote in post #8653520
Why a preflash? Didnt know that would happen other than for focusing.

cheers
Ali

The preflash is used to determine the flash exposure required in ETTL mode. Since the 420EX is a fully automatic flash (no manual option), it will always operate in ETTL mode and hence, will always fire a preflash.

For focusing, the flash emits a red patterned beam via the focusing lights (covered by a red plastic piece) located in front of and on the lower part of the body.

PacAce wrote in post #8654510
The preflash is used to determine the flash exposure required in ETTL mode. Since the 420EX is a fully automatic flash (no manual option), it will always operate in ETTL mode and hence, will always fire a preflash.

For focusing, the flash emits a red patterned beam via the focusing lights (covered by a red plastic piece) located in front of and on the lower part of the body.

So when it is working normally the flash fires twice? I have never seen it do that.

cheers
Ali