Question about Canon SPEEDLITE 580EX TTL Flash

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420EX Flash and Preflash Shooting all power

My preflash used to only use 1/8th of the power but now it uses all of the power, so I have to wait the recycle time and the calculations don't make much of a differece, as the flash without preflashing also uses all the power. And then my shots underexpose (even close up) as if my shutter is faster than my flash.

I've never had this problem happen to me but now it is. Any ideas?

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Re: 420EX Flash and Preflash Shooting all power

If the flash fires but the photos are dark, this typically indicates a fault with one of the following:
- fault of the main transistor that triggers the flash
- fault of the fiber optic cable that connects the flash head with the body

What you have to understand is that when you see one flash in operation, on a properly functioning unit there are actually two flashes in sequence. The first, pre-flash is used for metering the scene, then the follow up is the actual flash that gives the light in the photograph. If the transistor is faulty then it may just discharge the capacitor during the pre-flash, not leaving any energy left for the main flash. If the fiber optic cable is broken (it is very fragile), then the metering stage fails and the flash logic decides to abort the main flash.

Posted on May 12, 2013

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Re: 420EX Flash and Preflash Shooting all power

I have exactly the same problem with my 580EX flash, can you let me know if you find a solution?



Posted on Feb 20, 2008

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This may seem dumb to ask but have you made sure all batteries are fresh (even new ones can be bad), they\'re inserted correctly observing polarity and the contacts are clean in the flash? (You can clean them using a clean, dry pencil eraser and a Q-Tip dipped lightly in alcohol.)

Also, try mounting the flash on your camera, turn both on and reset your camera to factory default settings through your camera menu settings.

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My canon speedlight 420ex is dead as a doornail. Tried changing batteries, no good, is this the end??

Does the 420EX power up at all? As soon and I turn mine on while in the bounce flash position it immediately searches for focal length and the red light flashes I can also hear it powering up. If you hear this then the problem is most likely the flash tube which can be a bit pricey but a heck of a lot less then replacement new or used. IF there is no sound then it could be battery orientation (I've got the batteries in wrong so many times it's embarrassing) If the batteries are in correctly then the connections down inside the chamber may be corroded and require cleaning. Also the contacts on the some what flimsy battery door should be cleaned. If all this fails to produce a working unit it still could be repaired but ask for a quote first, most of the time it's just a dirty connection or the one wire at the bottom of the battery chamber it broken away still not an expensive repair when looking at replacement. Check things out before giving up hope. I've sent flash units to Canon Canada (as a business) had them back in 14 days and it cost me $80.00 Canadian including the shipping. Hope this was some what of a help

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Underexposure with Nikon SB-600 flash

1 - Make sure you don't have your diffuser screen pulled down. This is easy to overlook and will produce that effect.
2 - Reset your flash - hold down the "Mode" and "On/off" button together for a few seconds. This gets you out of any funky mode you could have accidently put yourself in
3 - Put camera in fully auto mode. That clears any weird modes you could have gotten into there
4 - Clean the contacts on the flash and camera. I use a pencil eraser and wipe with alcohol and paper towel. Dirty contacts can cause flash misfire or cause full flash during the preflash mode, which gives you dim or dark photos or sporatic flash operation.

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The flash is not in sync with my nikon d40 anymore. It fires first. Pictures come out dark. The camera itself takes great flash pictures

It sounds like you're trying to use the SB-600 off camera, as a slave flash. While the SB-600 does indeed have slave capability, the D40 does not have the ability to function as a commander. Thus, the SB-600 is being triggered by the D40's pre-flash.

As stated above, the D40 does not function in commander mode. You can mount an SB-800 or SB-900 flash unit, which will function as a commander as well as a flash. Or you can mount an SU-800 commander unit.

Alternatively, you can switch the D40 to manual flash mode so as to eliminiate the preflash. However, you will then have to calculate the proper exposure yourself.

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