Light Meter Questions

[Miller Best]

I'm shooting a scene on Eterna Vivid 500T 16mm film in a fairly dark bar.

 

Unfortunately I don't have the budget for tests at the location, but I've been there to take some readings. However, my light meter only performs incident readings.

 

At ASA500 25frames, my incident reading is about 0.7 - obviously I'm going to need more light (my lens opens to 2.8), and I'll be bringing some redheads along- that isn't a huge issue.

 

However, I'm wondering about the importance of spot metering and whether or not it'll help me much better. There's a few prac lamps and hotter areas in the frame, and, while at 0.7 incident reading, I'm sure these spots would be much brighter, perhaps at 4 or 5.6.

 

So, judging from my incident reading of 0.7, if I exposed at 2.8, theoretically the whole picture would be underexposed 3 stops right? And that's getting a bit risky for the latitude of 16mm, potentially having a crushed black image? But, if I were to have a spot meter, and had readings around 4/5.6 for the prac lamps in shot, would that mean they are 1/2 stops over, and will hence be exposed correctly, while the blacks are quite underexposed?

 

So, correct me if I'm wrong, a scene with an incident reading at 0.7, shot at 2.8, will be quite underexposed and crushed, while the lamps and highlights in shot will be correctly exposed, leaving me with an almost crushed black image with small white spots throughout ?

 

Sorry for the confusion, essentially I'm just wondering if I'm metering correctly (without using a spot meter), and if I'm understanding the spot meter correctly.

[Mark Kenfield]

It depends entirely on the relative ratios you'll get from the areas of the location you'll be shooting in. If your lightmeter is reading an f/0.7 at 500 ISO, then at f/2.8 you're a whopping four stops under for the general scene, with your f/4-5.6 practical lamps 1-2 stops over. Which pretty much means you ain't seeing anything but lamp shades and blackness.

 

If your subjects are close enough to the prac lamps to get a reasonable exposure on them (let's say f/2 for arguments sake), then you'll be able to see something of them (at a stop under) but everything else is still going to fall off into blackness. So it's all just relative to your shooting stop.

A spotmeter won't really tell you anything that you can't find out from positioning your incident meter around the set - it's just a simpler way to take a reflective reading.

 

All of which is basically just to say that, yes, you're right - the current lighting there will give you lampshades and blackness. Bouncing your redheads up into the ceiling or off some muslin should hopefully give you enough stop to capture some detail in your shadow areas.