need some help for an idea I have, regarding long exposure with a sillhouette

[CouncilmanDoug]

So in my head I have an idea that I'd like to create, basically i want a properly exposed long exposure of water at a beach at night, but I would like to have a model stand about ankle-knee deep in the water and pop a flash behind them and create a hopefully sharp sillhouette of them with rimlight. I was just trying to figure out what the best way of doing this would be, like if I have the person stand there the entire time won't their inevitable movement make it too blurry? or if they are only there for the flash won't the background ghost really heavy into the image? Any insight you guys could give me would be awesome, I might go to the beach tonight.

 

[KmH]

If the exposure of the water is long enough, the model can stand out of the scene until just before you fire the flash that provides the rim light.

How much ambient light (light pollution) does the beach have?

 

[CouncilmanDoug]

it is fairly close to a road, but it isn't very busy at night. I guess I'll just shoot with the fastest realistic shutter speed I can and pop the flash near the end of the exposure.

 

[squirrels]

Compaq may have tips? He did something cool kind of like this.
http://www.thephotoforum.com/forum/landscape-cityscape/305742-night-sky-fill-flash.html

 

[Buckster]

Any light behind the model, city lights, stars, glow in the sky, etc., will show up through the silhouette if the model isn't there the whole time.

I would try it with the model in place the whole time, staying as still as possible, and as long as the movement isn't a lot, I don't think it will matter much, as the flash will define the outline and light the edges enough to make any blur along those edges irrelevant and unseen.

 

[CouncilmanDoug]

Compaq may have tips? He did something cool kind of like this.
http://www.thephotoforum.com/forum/landscape-cityscape/305742-night-sky-fill-flash.html

that last one is definitely similar to what I want to achieve, looking at those made me excited for trying this out

 

[squirrels]

Compaq may have tips? He did something cool kind of like this.
http://www.thephotoforum.com/forum/landscape-cityscape/305742-night-sky-fill-flash.html

that last one is definitely similar to what I want to achieve, looking at those made me excited for trying this out

Woot! I'm excited to see what you come up with!

 

[CouncilmanDoug]

and I guess I'll try out both techniques, I'm sure one of them will fulfill my vision haha