[Bald Runner]

Hi,

I am currently reading Scott Kelby's "The Digital Photography Book, volume 2" which is full of good tips. He mentions a technique called 'Rear Sync' for use with flash photography.

I cannot find anywhere on the 400D menus, a setting for this. Perhaps the 400D cannot be set to Rear Sync? Advice welcomed!



Thanks

Mark

[gsgary]

Originally Posted by Bald Runner

Hi,

I am currently reading Scott Kelby's "The Digital Photography Book, volume 2" which is full of good tips. He mentions a technique called 'Rear Sync' for use with flash photography.

I cannot find anywhere on the 400D menus, a setting for this. Perhaps the 400D cannot be set to Rear Sync? Advice welcomed!



Thanks

Mark

If you have a 580ex flash it will automatically set it, not sure if it will with the 400D

[silkstone]

He may be referring to what is often known as 'second curtain flash'.

The duration of the flash is very short - much less than the time for which the shutter is open - and usually the flash fires as soon as the shutter opens. That's fine for most purposes, but if, say, you're photographing a moving car at night, the flash will freeze the car but then the car's lights will continue forward and show as 'trails' on the image - making the car look as if it is moving backwards.

With second curtain flash, the flash fires at the end of the exposure time instead of the beginning, so you get the car in front of the light trails.

You can set second curtain flash on many cameras from the Custom Function menu, but it is usually easier to set it on the flashgun.

HTH!

[danpen]

Hi,

Go into the menus
Jump until you're at the 6th menu from the left (middle yellow one)
Flash Control is at the bottom
If you're using the built in flash, choose it and then choose Shutter Sync: 2nd Curtain

You can set it for an external flash here but as others have said its easier on the unit.

I use this from time to time when photographing cyclists and although I'd usually use the exernal flash I do have it set up on the "My Menu" screen for ease of access (along with mirror lockup)

Cheers

Dan

[Larne]

Personally I can't understand why 2nd curtain flash isn't the default. If the subject isn't moving then it doesn't make any difference. And if it is moving in how many scenarios would you want any motion blur to be ahead of the flash frozen image?

As you might guess I have everything set to 2nd curtain and never use anything else.

[silkstone]

There are a few reasons why cameras ship with first-curtain flash as default, although they may not matter depending on what sort of shots you take.

One is that it's more difficult to photograph a moving object with slow shutter speeds and second-curtain flash. Because the flash fires at the end of the exposure, you're trying to track a subject that you can't see through the viewfinder because the mirror has flipped up.

The second is that the pre-flash for ETTL exposure happens at the start of the exposure, so if the flash actually happens at the end there's no guarantee that the exposure will be correct.

With a long exposure there will also be two visible flashes for the pre-flash and main flash, which could confuse people if they're expecting only one flash.

On the whole, though, I think that second curtain flash should be OK for most shots.

[Bald Runner]

Thank you all for your replies. The setting is in the Custom Functions

Thanks again

[morlandroger]

Bald Runner, you got it. Multiple answers but the right one was there somewhere. That is why I love this place. A bit of something for everyone.

[ds00kg]

Funnily enough I was playing about with this last night, it is a tad confusing to have the 'pre-flash' even when it's set to 2nd curtain flash. Anyone know why this is? I don't see how it's used for the AF

[silkstone]

The pre-flash is for exposure, not AF. Auto flash exposure (ETTL, ETTL-II, etc) is independent of the normal non-flash exposure control built into the camera, so it works even if the camera is set to Manual exposure. With the flash switched on, the camera measures the light reflected back from the pre-flash to determine the correct flash intensity for the shot.

[ds00kg]

A wealth of information! Thanks Silkstone

[stepheno]

Originally Posted by ds00kg

A wealth of information! Thanks Silkstone

It takes an engineer to come out with explanations like those

[silkstone]

It's why I fiddle with things instead of using them.