In light of very disappointing initial results, I'm triple checking myself here... I'm doing some work for a friend, shooting elements for CD cover art for a garage band he's been working on. I recently shot a wisp (plume?) of cigarette smoke to be composited with the band's name for the cover of the CD.
Shooting Vision 500T (5279) rated at 400 ISO, I used a 6x9 ERS from about a 3:00 position to sidelight the smoke against a black (duevetyn) background. I incident read the ERS at T8 (at 1/125 of sec (shooting slides)) and shot at T8... Shooting very close to the plume of smoke (only thing in frame, cigarette was below frame line) about a foot away... Got back a VERY thin (anorexic) negative with damn near NOTHING on it...
I'm at a loss...
HOWEVER...I did not shoot a gray scale...and damn near everything I have run through this lab in recent months has come back disappointing... (how can you tell if something has REALLY been pushed when you can't trust printer lights or the lab??)
Any thoughts would be fantastic. As a side note, I didn't directly backlight the smoke (from a 12:00 position) because I was forced to shoot this outside and I was avoiding all the other extraneous crap in the air...
>incident read the ERS at T8 (at 1/125 of sec (shooting slides)) and shot at T8...
Did you happen to take a spot reading of the smoke ? If it's a really whispy cigarette smoke, it might not have been thick enough to catch enough side-light. If the smoke were f-5.6 spot (brightest parts of smoke), then a t-3.5 lens stop would have yielded a thicker negative (a light-gray smoke). Incident to ERS may still say f-8.
As was implied, had the smoke been backlit at T-8, it may have exposed a little brighter on the neg. But side-lighting works if you're a spot-meter
With smoke elements against black, it's best to overexpose 1/3 to 1 stop since most of the frame (behind the smoke) is black (1/3 stop was done by rating the film at 400). You have a choice in post to composite the smoke white, or with less luminance: gray.
Of course, it could be the lab, the film, the meter, the camera, the lens, the light got bumped...but it seems one of the biggest variables would be the density of the smoke, no ?
Or maybe it really didn't stay in the soup long enough...
Side-lit smoke is not going to be nearly as visible as backlit smoke. Also, if you metered the wisp of smoke with a spot meter from the camera position, you would want to open up from what the meter gave you, since the wisp should be white-ish against the black background, not medium grey. If you read a t/8, you probably should shoot at a t/4.
I find that when filming against a black background, sometimes the subject itself needs to be a little hot for the image to feel correctly exposed - in other words, the frame should have a range from something dark to something hot. If you put something medium grey against something black, it feels a little murky. This becomes even more important in black & white
photography; the image needs a certain "snap" - a nice dynamic range of blacks, greys, and whites.
Wow, how much extraneous crap is there in the air where you shot, if you have to worry about hiding it and at the same time you're not getting exposure on your side-lit smoke?
I don't know about metering this stuff, smoke efx are an eyeball thing to me. If this is a still you can bracket anyway.
And - are you shooting then 5279 as a still film? Do you really trust the still labs that do this stuff ?
I've found that to 'sell it' with smoke you need easily 2 or 3 times as much smoke density as your eye thinks, and maybe more. I've used 5 or 6 cigarettes mashed together out of frame just to represent one.
I did some medieval church scenes in my feature "Wired Angel" with a censer. For about 3 or 4 setups, I bought a pound of incense. The religious supply shop said something like "that would last a Church a month or more"
And I was very tempted to suplement the real incense with a Rosco 1500 and a plastic tube...It's just that thin line between realism and overdoing it.
Also, 3:00 is maybe too subtle. You _must_ give smoke, steam, etc enough backlight.
And as I'm sure you know, saying the words "roll camera" will always cause a change in wind direction...
-Sam "get a good Key Wafter on the crew" Wells
I think Mark has "nailed" the problem. Smoke is translucent. Incident light readings work fine for solid objects. Only a spot meter reading will read "smoke on black" with accuracy.
This doesn't mean that you may not also be having problems in one, or more, of the things you mention, but this incident reading sure looks to be the "culprit".
By the same token, I think you can get away with more in B&W, you need the snap and can get away with it. My church scene was in B&W, I was in a sense photographing not just the incense smoke but the 'impression' of incense smoke in a dimly lit church.
Presumably Jay's shot is in color, so the cigarette smoke would be blueish.
Also, smoke is going to be a various densities at the same time. Which is why I say it's as much a light it by eye as a light it by spot meter.