Rear curtain sync on 7d

pooley

pooley

Messages
6,027
Name
Mike
Edit My Images
Yes
A bit of help please if you are in the know!

A bit of background first. I'll be doing some underwater photography soon, and as such there is no way any other equipment other than what I already own can be used or suggested. One of the ideas I have involves using a long exposure with a 2nd curtain sync but I can't seem to get my camera set up.

Reading various other threads and searching the web has drawn me a blank - I can't use speedlites or yongnou triggers or anything like that which would normally be the way forward. Basically, my 7D goes into the housing, and a hot shoe connector slots onto my hot shoe. In turn, that connects to my flashes (called strobes underwater - the models are 'inon z240's). Everything is shot in manual mode without the option of ettl or any other such wizadry.

Does anyone know if there is a camera setting i can change?

thanks

Mike
 
With Canons, second-curtain sync is part of the E-TTL control system, so unless your flash unit is fully E-TTL compatible, you're snookered.

What exactly do you want to do? Forgive me, but second-curtain sync is often misunderstood and may not be necessary ;)
 
Cheers Richard, I had a feeling that was going to be the answer. The idea revolved around shooting some quick darting fish with a coral background.

There will be plenty of fish and I can get physically very close with the idea being the coral providing the background with a fish moving across it. The fish would be sharp with the flash but leaving a blurred streak behind it from the ambient light
 
pooley said:
Cheers Richard, I had a feeling that was going to be the answer. The idea revolved around shooting some quick darting fish with a coral background.

There will be plenty of fish and I can get physically very close with the idea being the coral providing the background with a fish moving across it. The fish would be sharp with the flash but leaving a blurred streak behind it from the ambient light
Click to expand...

Yes, second-curtain sync would work well for that. Very well I would guess :) Though bear in mind that it's not active at shutter speeds above 1/25sec anyway, even when enabled, and doesn't get properly in line with the second-curtain until longer than that.

There are some fairly complicated and cumbersome workarounds on dry land, but they're not even a possibility for you. So unless you can get a fully E-TTL flash down there, second-curtain is out. Shame really :(
 
pooley said:
D'oh

I was thinking it might not be possible, but thanks for the replies - I've got a couple more weeks to think up some fresh ideas then
Click to expand...

Does your flash have an optical slave sensor? If it does, you could sync it off the 7D's pop-up - if you can get the pop-up to pop up. In manual, with second-curtain enabled, it will fire just one flash (no pre-flashes) at the end of the exposure.

It'd be worth trying the technique with normal first-curtain sync though, see how it looks? Wouldn't be much different to second-curtain until you get down to say 1/8sec shutter speed.
 
You must log in or register to reply here.
Back
Top