2nd curtain /slow sync + wireless

[ddr]

Why is slow sync not a common feature in wireless triggers, other than higher end models?

if i'm using a flash at night, and i can't use 1/250 (w/o jacking up the iso) to properly expose for ambient light, i find it useful to use slow sync to freeze my subjects (since it happens at the end of my exposure).

just curious. i could be getting this completely wrong.

TIA

[i speak in math]

Originally Posted by ddr

Why is slow sync not a common feature in wireless triggers, other than higher end models?

if i'm using a flash at night, and i can't use 1/250 (w/o jacking up the iso) to properly expose for ambient light, i find it useful to use slow sync to freeze my subjects (since it happens at the end of my exposure).

just curious. i could be getting this completely wrong.

TIA

You can do front curtain no problem. That will freeze your subject.

Thats what I did here. 10 sec shutter with a flash at the beginning.


You can't do rear curtain because the wireless flash would need to know how long your shutter is to know when to go off. Since the triggers aren't relaying setting information (only, trip flash now) it can't use rear curtain settings. Some high end triggers do pass the TTL info and can do rear curtain. It depends on how much its worth to you to be able to do it.

[ddr]

thnx. i totally forgot about relaying the settings part.

for the picture in your example, was the subject moving along?
how come it didn't register any motion blur? was it because it was too long to do so?
would this be the same case if it was a scenario that required a shutter speed of 1/4?

[sk66]

The key to using flash and not catching the motion as in the photo above is having the "scenery" exposure be quite long in relation to the flash time....It requires a tripod. The exposure above was 10 sec..I would expect 3-5 seconds to be the minimum situationally dependent.

[inkista]

Originally Posted by ddr

...how come it didn't register any motion blur? was it because it was too long to do so?

No, it's because he wasn't lit while he moved across the frame. Because he was so dark when there wasn't any flash his moving image didn't add to the overall exposure enough to be seen. The "frozen" part is when the flash burst went off. The flash burst duration is very short--much shorter than your maximum shutter speed.

would this be the same case if it was a scenario that required a shutter speed of 1/4?

Yup.

[ddr]

thnx everyone

time to experiment!