Calculating long exposure for night photography

Hi-

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I'm planning on doing some night photography with 4x5 in color... specifically wide angle stuff of neighborhood streets and parking lots. A couple questions:

1) How do I calculate exposure without exposing $1000 worth of polaroids?

2) How do I calculate for natural light (moonlight) and artificial light (streetlights)?

3) Do I need some sort of light controlled by me (flash, strobe, whatever...)? I'd rather shoot entirely with available light, but maybe someone knows of a reason why this is impossible.

4) Spot meter or incident meter?

5) Is there some resource for learning everything I might need to know about lighting for this particular project? When I had the chance, I didn't take advantage of lighting classes, thinking I would never need them. Oh what a jerk I am.

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Any help is greatly appreciated.

Thanks,

Bryan

250,000 times sunny sixteen. This will work for shots under a full

moon with the moon over your shoulder. Color balance will be the same

as daylight (the moon is reflecting the same sunlight). You will have

to consider reciprocity departure, which for color film may involve

time/aperture as well as filtration.

Shooting and preserving your sanity at night with colour film is

tricky. How about a beefed up scouting expedition? Go out one night

to seek out your 4x5 set-up positions and shots, but take a 35mm

camera loaded with the exact same emulsion as your chosen 4x5 film.

Set your 35mm on manual everything, manually meter, bracket every

shot like crazy, but most importantly make very careful notes!

Burning a few rolls of 35mm (or even 120/220) is pretty cheap, wasted

4x5 sheets aren't. I'm not saying you'll get perfect results, but

you'll at least get a better idea of the relationship between night

meter readings and the final results. You can also get some feedback

on what shutter speeds yield the best car head/tail light trails, if

that kind of thing's your bag...

Color film at night is very difficult as someone else noted, in part

because there are so many different kinds of outdoor lights, each

requiring different color balancing filters (unless e.g. you like

everything to look green or blue or whatever). I can't help you there

but I did learn a good trick for figuring the initial shutter

speed/aperture setting when the light is too dim to get any reading

from your meter (I say initial because reciprocity adjustments

probably will be necessary but at least you'll have the starting

point for those adjustments). Set the ASA dial on your camera or

meter to its highest setting - say ASA 6000. At that film speed

you'll almost certainly get some kind of reading. Then mentally work

backwards to your actual film speed using the principle that each

halving of film speed reduces the exposure by the equivalent of one

stop. For example say you're using a 400 speed film and can't get a

reading from your meter. Set the meter to ASA 6000 and you'll

probably get a reading, say it's F 2.8 at 1/2 second. Mentally

reducing the speed to 3000 would result in a shutter speed of 1

second, reducing it to 1500 would be a shutter speed of 2 seconds,

reducing it to 800 would be a shutter speed of about 4 seconds (with

these times exactitute in the hundredths of seconds isn't necessary),

reducing it to 400 (your actual speed) would be a speed of 8 seconds.

So now you have a starting point of F 2.8 for 8 seconds and can make

your reciprocity adjustments. Or if you want to use a smaller

aperture just increase the shutter speed accordingly. Sorry, this

explanation went on for a lot longer than it's probably worth but

hopefully it will be useful.

The good news is that the $1000 of Polaroids would serve you no

purpose whatsoever. The polaroid film will have different reciprocity

failure characteristics than the negative/positive film that you'd

use.