slow sync flash mode

[chjing]

hi, can anyone tell me how to switch to slow sync mode when using a flash?

 

[sammy888]

hi, can anyone tell me how to switch to slow sync mode when using a flash?

It would help us to help YOU if you actually tell us what camera, what flash you are talking about. No one is going to guess what it is since difference camera and flash models exist and they might not all get swtich on the same way.

 

[chjing]

Canon 350D and 430EX

 

[ykia]

First, decide if you wish for the flash to fire on 1st or 2nd curtain (selectable by CFn, read manual).
Assume u get a 2s shutter exposure...
1st curtain = flash fires at the very 1st moment the shutter opens -- good for non-moving subjects
2nd curtain = flash fires near the end of the 2s exposure -- good for moving subjects


Then there are 3 ways to get slow synch with the 350D:
1. Set the mode dial to "NightShot".
2. Set the mode dial to Av and select your aperture.
3. Set the mode dial to M and select your aperture and shutter.

 

[chewraisins]

There's a button on the 430EX with a "flash(H) / forward symbol" (3rd button on top row).
IIRC, pressing it once activates high-speed sync, and another press will activate 2nd curtain sync.

So what you should do is..

1. mount 430EX on cam & power on
2. set Aperture, Shutter values
3. press 3rd button on flash twice
4. shoot away

Cheers,
Andrew

 

[cantaresg]

One thing to take note. Since you are taking a slow sync image, the exposure should be long. Say about 10-30s?

 

[chjing]

thanks. but i have one more query. I read on websites saying that using slow sync mode you can lit up your friend in the foreground as well as brighter background due to slower shutter speed, but the thing is : your frined (subject) will have motion blur cos they will not stay motionless. if you use slower shutter speed, wont you need to tell your friend not too move before the shutter ends? how can you possible ask your subject not to move till you say so?

 

[cantaresg]

If your friend does not reflect much light, there may be some blurring, but since your friend is near to you, the flash provides the main lighting for your friend. As such, you can still obtain a clear focused image with motion blur. That is the uniqueness of slow sync flash.

 

[eejal]

Edited.

 

[Scaglietti]

thanks. but i have one more query. I read on websites saying that using slow sync mode you can lit up your friend in the foreground as well as brighter background due to slower shutter speed, but the thing is : your frined (subject) will have motion blur cos they will not stay motionless. if you use slower shutter speed, wont you need to tell your friend not too move before the shutter ends? how can you possible ask your subject not to move till you say so?

I will tell my subject try not to move. Usually I use the rear curtain (2nd curtain) sync, because the tendancy is for the subject to move after the flash. So I leave the flash right at the end of the exposure.

BC