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class="style14">Low Pressure / Temperature Filming

>Published : 8th Nov. 2006

>I know NOT video or HD but need film and video comparisons:

>Does anyone know if the Sony 750 (or DigiBeta 790 for that matter) have any problems with operation in low pressure and low temperatures?

>I need to put a camera in a decompression chamber with the Royal Air force which can be simulated to 30,000ft.

>I know NASA used to use the SR1/2' in extremes etc but has anyone put any HD kit through this?

>There is also a possibility of rigging several small cameras that will have to operate at 34,000ft (approx -57 degrees Celsius) bearing in mind the condensation on the way up later becoming ice, would S16mm win hands down without building special rigs? Obviously underwater housings are designed to excerpt the pressure the other way round, so unless they can take negative outside pressure unlikely?

>Anyone filmed on or in high level balloons on any formats?

>Dave le May
DOP Cinematographer
London
www.davidlemay.com


class="style15">>There is also a possibility of rigging several small cameras that will >have to operate at 34,000ft (approx -57 degrees Celsius) bearing in >mind the condensation on the way up later becoming ice, would >S16mm win hands down without building special rigs?

>Are these cameras going inside or outside the aircraft? How small do the cameras have to be?

>ARRI specification for the 16SR gives a temperature minimum of -20ºC. This specification may be related to the minimum temperature for the NiCad batteries. The standard lubricants I use on the 16SR's during overhaul is rated to -50º C.

>I think with the proper preparation S16 film cameras can be set up to withstand the low temperature, except the NiCad batteries which will NOT work at those temperatures. You will have to use Lithium battery or use aircraft power (110V 400Hz 3Ø) rectified to DC voltage converted and filtered.

>Properly shot professional HD video (not HDV) and Super 16 mix well and can be combined in the project.

> Jorge Diaz-Amador
Designer / Technician
CinemaTechnic, Inc.
Miami, FL USA
http://www.cinematechnic.com


>OK, so an SR can run at -20 degrees F...

But at what temperature does film freeze and break?

Cheers,
Jeff Barklage, s.o.c.
US based DP
www.barklage.com
view reel online
http://www.reelsondemand.com/jeff_barklage/index.html


class="style15">> OK, so an SR can run at -20 degrees F...
> But at what temperature does film freeze and break?

>At least -20º C [-4º F]. As I said the lubricants can handle -50º C. Arri’s spec may be a conservative one based on the voltage drop of the Ni-Cad batteries which were considered a part of the 16SR camera.

>Re the film, I was thinking the same thing. However, the film is NOT going to freeze because it is not water based. I assume that it can become more brittle in extreme cold. With very low humidity static electric discharge will be a problem as well and the cameras will need to be grounded.

>Obviously this did not stop the SR-71 spy planes flying at 100,000 ft altitude from shooting plenty of film. They shot 9 inch [229 mm] wide rolls of film using huge lenses with 200 lp/mm resolution. About 800 megapixels for a 9 x 9 inch image!

> Jorge Diaz-Amador
Designer / Technician
CinemaTechnic, Inc.
Miami, FL USA
http://www.cinematechnic.com


>Hi,

>One would suspect that a solid-state recording medium such as P2 would do better in these circumstances, but you'd still have to watch any gas-tight units in the lens assemblies or whatever.

>Phil Rhodes
Video camera/edit
London


>Jorge Diaz-Amador wrote :

class="style15">>Re the film, I was thinking the same thing. However, the film is NOT >going to freeze because it is not water based.

>But film does contain a certain amount of moisture; and plastic will certainly freeze. At a certain temperature MP film will snap if it is bent. In any case, at around 0 degrees F. film is extremely difficult to handle and it is very easy -- almost inevitable -- to break a loop when loading any camera with tight loops.

class="style15">> I assume that it can become more brittle in extreme cold.

>That's for sure. What's more, the sharp edge of thin films can become a definite laceration hazard, broken film even more so. And Band-Aids won't stick.

Brittle or frozen, I think that's a semantic question. There doesn't seem to be an exact temperature at which film freezes, but it gradually gets stiffer to the point where it can't be handled, especially if it's being bent against the wind, or emulsion out.

class="style15" >With very low humidity static electric discharge will be a problem as well >and the cameras will need to be grounded.

>Usually the film is not moving fast enough to build up any static, but through the mounts, the cameras are attached to the fuselage. The planes themselves only generate static at lower altitudes. At operating altitudes, there is not enough atmosphere for static to be a problem.

class="style15">>Obviously this did not stop the SR-71 spy planes flying at 100,000 ft >altitude from shooting plenty of film.
>They shot 9 inch [229 mm] wide rolls of film using huge lenses with
>200 lp/mm resolution.

>The cameras are heated. Also the film is extremely thin in order to
increase capacity.

>As you might expect, David Samuelson's Manual for Cinematographers has some very valuable info on working in extreme cold, as does the ASC Manual.

>I think Kodak has quite a few publications about work in extreme cold.

>Brian Heller
IA 600 DP


>Not 100% sure correct post but original was posted on general :

>Un-pressurized flight, talking to the Royal Air force today they mentioned that a BBC film crew had a lens crack at 30,000ft effective pressure in the hypobaric chamber. I'm doing exactly the same and don't wish to have an insurance claim! Anyone BBC out there any info? Plus will be shooting at –20 degrees C. Keeping the mags/bats/body warm with heated blanket anyone used these at all for cameras?

>Dave Le May
Cinematographer
London
www.davidlemaay.com


>Dave Le May wrote:

class="style15">>Un-pressurized flight, talking to the Royal Air force today they >mentioned that a BBC film crew had a lens crack at 30,000ft effective >pressure in the hypobaric chamber.

>It doesn't happen often, but it can happen. It's probably a result of a defect in the lens. Unfortunately, you won't be able to find out in advance unless you get hold of a lens that has already been through the chamber.

class="style15">>Plus will be shooting at -20 degrees C. Keeping the mags/bats/body >warm with heated blanket anyone use these at all for cameras?

>See if you can get hold of a heated barney for the camera. It makes operating the camera a lot easier. I'd be surprised if Samuelson's doesn't have some for rent.

>Brian Heller
IA 600 DP


>I recall that NASA kept cameras that were mounted on rockets or launch pads sealed inside chambers that were filled with an inert gas. This helped protect them from changes in pressure, humidity and to some degree temperature. Must have been thick plates of tempered glass they were shooting through back in the 60s.

>Mitch Gross
NYC DP


>Phil Rhodes writes :

>One would suspect that a solid-state recording medium such as P2 >would do better in these circumstances, but you'd still have to watch any >gas-tight units in the lens assemblies or whatever.

Since the HVX-200 has a DV tape drive, it may shut down due to condensation "Dew Light" even though this would not affect the P2 interface. I have many customers that shoot video professionally and they have told me many stories about shoots being shut down by the "Dew Light".

>The difference in the amount of water vapour the air can hold at sea level and normal temperature versus high altitude is extreme. And all that moisture has to condense out of the air - it has to go somewhere.

>Unless you could completely desiccate the air in the camera and keep it sealed until you reach altitude you are definitely going to get condensation which will turn to ICE. The problem will be even worse when you descend and all that ice turns back into liquid water.

>These problems will affect a film camera equally. I would expect that older cameras (16SR2, 35-3) with discrete electronics would be more reliable than the newer Arri’s with complex integrated chips.

>BTW, I successfully refurbished an ARRI 16SR-1 that had been fully immersed in a fresh water lake. Fortunately the camera was well lubricated and there was minimal corrosion. If a camera gets dunked in salt water though, you have just created a very costly paperweight.

>AFAIK modern lenses do not have any hermetically sealed lens cells. I certainly have never encountered any in my lens repairs.

> Jorge Diaz-Amador
Designer / Technician
CinemaTechnic, Inc.
Miami, FL USA
http://www.cinematechnic.com


>I've had cameras briefly shut down due to extreme fog conditions but if the HVX shuts down in P2 mode that seems like a very poor design (and I highly doubt this to be the case). I agree with Phil, for these conditions a solid-state design does seem to be the best choice. I'm not a big fan of the P2 or HVX in general, but it certainly has its uses and this seems like one of em.

Jim Eagan
NY editor/shooter


>Kodak publication "Photography Under Artic Conditions":

http://www.kodak.com/global/en/professional/support/

techPubs/c9/c9.jhtml

>Film has been used in very cold conditions, dating back to Flaherty's "Nanook of the North":

>http://www.imdb.com/title/tt0013427/

>More recently, 65mm colour negative was shot on the peak of Everest, and in outer space. Another example of sub-zero mountain cinematograpy was "Touching the Void":

http://www.kodak.com/US/en/motion/newsletters/inCamera/

july2004/void.jhtml?id=0.1.4.3.12

>John Pytlak
EI Customer Technical Services
Eastman Kodak Company