Shooting Bubbles
Hi all,
I've got a spot coming up (hair commercial) where the director plans
to use bubbles as a transitional device between segments. I've never
shot bubbles before. I've got some macro lenses and a 25-250 Ang.
zoom. How fast should we run the camera (435)? Lighting tips and
background ideas would be much appreciated. CG not an option.
Thanks in advance...
Nick Hoffman
IA600DP
NYC
Nicholas Hoffman wrote:
>Hi all, I've got a spot coming
up (hair commercial) where the director >plans to use bubbles
as a transitional device
This sure sounds like a situation where you should explore the possibility
doing the transition in post, using some kind of 3D software. I
believe it would be a particle effect, and suspect you may be able
to get some pretty realistic stuff going. If it were me I would
discuss this with the Producer and Director.
Also, your specifics are vague. what kind of bubbles? Lawrence Welk-like
bubble machine? Bubble bath suds? Great big bubbles from one of
those gigantic bubble wands?
Just some thoughts.
Mark Schlicher
Writer/Producer/DP
Nashville, TN USA
I did bubbles not long ago, for a cosmetics company.
Clairmont macro lens (the Isco, as I recall, I'll have to check,
we had also tested a few others). The only lens we found capable
of 10:1 magnification. The art director wanted a single Champaign
bubble to fill the entire screen.
Also, high speed, up to 150 FPS. For this we needed an f/stop of
about f/128 or above at the subject (incident) in order to have
enough depth-of-field to keep the entire bubble in focus. After
various filter factors, high speed, etc. the actual stop on the
lens was about f/32 or thereabouts as I recall. Just barely enough
to hold the depth-of-field. I wrapped the Minolta mini-probe in
plastic wrap in order to get readings at the subject.
A small chamber made from two 4x5 optical clear filters, front and
back. Other arrangements were tried such as nitrogen in mineral
oil, etc.; none of which were acceptable. We were never able to
get pharmacy-grade, purified mineral oil to be acceptably clean
and optically transparent.
Lighting: a 12K HMI PAR about 30 inches away from the subject. Extensive
heat dissipation and protection precautions, obviously.
Clairmont strobes (similar to Unilux) had been tried on a test day,
but proved inadequate for the stop we needed. As I recall we rigged
some six or seven strobe heads, together with a 6K PAR and a 4K
PAR. Also, the art director didn't like the pattern of highlights
on the bubble in this arrangement. We "blended" the strobes
with diffusion, of course, but it still didn't produce the clean,
singular highlights he wanted.
Even with that firepower, ended up having the film pushed one stop;
it still looked great. Kodak Vision stock took the push and was
hardly noticeable. Two days of shooting; only got it on the last
take.
The final secret: use cheap Champaign — the bubbles are larger.
Good luck
Blain Brown
DP
LA
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