Lighting both foreground and background

Question

I have this scenario where is dark in evening I guess and I made an outdoor portrait using my flashes. What I wanted to get is the foreground face flashed and the background of the image properly metered. Thus I performed metering in the background that I need to be well lighted. This leads to many seconds of shooting. Thus my question is the following: what should the model is preferable to do:

• either to move quickly off the frame after the flash
• or to wait until the end of the shooting?

It is a simple case however since I am using film I dont want to use no click of my roll film.

Answer 1

You will have some gohsting "exept" in the case your model is sitting or laying against a wall, column, etc. In early portrait photography they build some rigs for the people. (well, your model will need to hold her/his breath for some seconds probably)

Do not make your subject "disapear" becouse it will look transparent... Or exploit that effect.

To exploit that use rear curtain sync flash. https://www.google.com.mx/search?q=rear+curtain+sync+flash

If you want to freeze as much as possible, use a higher ISO, beware of the extra noise you will get. You could use a faster lens, but you will probably have the background out of focus.

Or think of actually iluminating the background too, if you use radio triggers you can spread some flashes arround. You can also boost the dark areas in post pro. Actually you can take a separated picture to add detail on the dark areas masking a bit your subject.

• Support your model.

• Higher ISO.

• Boost the shadows in post production.

• Iluminate the background.

P.S. As mentioned in Pinhollow Euri answers you can also put your subject in a very low lit environment, but you will probably need a focus asistant beam.

Oh, an obvious thing... use a tripod.

Answer 2

Model walking away will discover the part of the background and some kind of ghosting will happen - both the model and the background will be visible. Model should wait until exposure end.

This raises another problem: if the exposure is long enough then the blurred image of model may become more visible than desired. Take this into account when choosing exposure. Most probably you won't be able to make background as well lit as model without introducing mentioned defects - unless you place model somewhere in the shadow so that blurred image of model does not appear.

Here is an example of what happens if model leaves.