portrait, flash, tricky lighting

I've been asked to make a color photo of a family against the

background of a lighted monument at night. I want to use ambient light

to shoot the monument but flash to shoot the family.

I'm shooting a Nikon F4 and I figure I put the camera in manual and

spot metering and meter the monument for a proper exposure. Then I put

the camera on a tripod, put the flash in TTL and in slow sync/rear

curtain flash.

Then I probably set the film speed to compensate for flesh tones,

perhaps one stop slower than the rated film speed to get a stop more

light, and make sure that the spot meter circle is on a face when the

flash goes off.

What have I forgotten, or misunderstood? What other settings might I

use? Or can I trust matrix metering and auto fill flash in this

situation?

I don't understand the need for rear curtain sync in this situation (unless somebody in the flash zone has a glow stick or other light source they are moving around for an effect).

In addition to trying TTL in spot mode with flash compensation for the tone of the spot, I would take a some exposures with the flash in manual setting the power level based on guide number calculations of the aperture and subject distance (or better yet a flash incident meter at the subject distance).

I don't trust TTL matrix metering anytime a significant portion of the background needs to go black and the flash is the main light for a portion of the frame, not that it won't work, it is just too easy to get faked out and not understand what the camera/flash is going meter and how to place it tonally.

Look out for any light, reflective, or medium tone surfaces in the foreground frame and take care to keep the flash off of them if you can. You don't want a really bright sidewalk a few feet from the camera that gets darker toward your subject.

This is one of those situations where auto anything is a liability not an asset. If I were doing this shot I would put everything in manual including the flash and use a flash/ambient meter.<p>

Since you don't have that luxury, if I were you I would forget about slow/rear curtain flash and changing the film speed. (What for?) <p>

Put the F4 in manual, meter for the background however you feel you would like to do it (spot or matrix) and set your aperture and shutter accordingly. <p>

Use matrix balanced fill flash (matrix metering on the camera) and bracket the hell out of it with the flash comp. Matter of fact I would probably bracket the aperture +/- 1 stop too just to make sure you get the background the way you want it. <p>

You ain't gonna nail this one in one shot unless you get lucky.

I did something similar, taking some photos of my cousin on the top of the Montparnasse Tower in Paris, by night.

So I set up my camera in aperture priority using matrix metering on the background - 30sec. I composed the picture with my cousing+boyfriend in the foreground, and I told them not to move for the time of exposure.

I set the flash to manual mode and adjusted the correct exposure for the foreground. While the exposing the background, I had enough time to play around with the flash and fire it manually, while aiming it to the couple.

The exposures were just great. A bit dull, as I was using only one flash, but we've got what we wanted. Next time I will use at least two flashes, all in manual mode.