I now have my vivitar 285HV!

[leightonjames]

And i love it. But. I can't seem to select a shutter speed any faster than 1/400th. Is this not going to be possible or is it a problem with the flash itself? Im shooting on a 40d.

Cheers

L

[Simpo Two]

Can't speak for a 40D but the max synch speed on a Nikon is 1/250th (unless you choose high speed mode which robs power). So 1/400th seems pretty good to me. Are you photographing bullets? ;-)

[leightonjames]

haha, well i could have sworn i read somewhere about highest sync being 1,1000th on the flash? I wasn't sure what speed i would need but 1,400th is a bit limited to me.

[VxDuncan]

It's all down to the mechanics of the camera. You try opening and closing a shutter and triggering a flash to go off just as the shutter is fully open at faster than 0.0025 secs!

Yes it is a limitation, but that's life. Can be a pain when you want to use fill flash outdoors for instance.

[_dobbo_]

1/400th is pretty good, as I recall the lower ranged of Canons are all rated at 1/250th, not sure about the 1D range however.

Under what conditions when flash is required will you need faster than 1/400th?

Edited by _dobbo_ on Sunday 16th November 20:49

[flat-planedCrank]

leightonjames said:

haha, well i could have sworn i read somewhere about highest sync being 1,1000th on the flash? I wasn't sure what speed i would need but 1,400th is a bit limited to me.

The 40D's fastest flash sync speed is 1/250th

If you want to use a higher shutterspeed then EX flashes, or i guess other compatible flashes, have a high speed sync mode (pulses the flash quickly - effectively turning the flashgun into a 'normal' light - robbing power / range).
If you can set your camera faster than 1/250th so maybe its enabling hss automatically ? Dunno


Afaik, other cameras (like expensive medium format stuff) use leaf shutters in the lenses to allow for higher flash sync speeds.

_dobbo_ said:

1/400th is pretty good, as I recall the lower ranged of Canons are all rated at 1/250th, not sure about the 1D range however.

Under what conditions when flash is required will you need faster than 1/400th?

Think most are 1/250th. Curiously the US Canon site rates the new 5D mk2 at 1/200th - the same as the 450D.


Cheers.

Edited by flat-planedCrank on Monday 17th November 04:38

[nick_bbb]

This video explains what is going on with flash and the shutter...

http://uk.youtube.com/watch?v=Xnn5nzPvoIM