Where there's smoke there's [fill in the blank]. - Page 2 at DVinfo.net
DV Info Net

Go Back   DV Info Net > The Tools of DV and HD Production > Open DV Discussion

Open DV Discussion
For topics which don't fit into any of the other categories.

Reply
 
Thread Tools Search this Thread
Old November 6th, 2002, 12:28 AM   #16
Slash Rules!
 
Join Date: Apr 2002
Location: Houston, Texas
Posts: 5,472
I thought dry ice was frozen CO2 (what you exhale) and therefore, when it "melted" it would simply release gas into the air, not liquid.
Josh Bass is offline   Reply With Quote
Old November 6th, 2002, 01:20 AM   #17
Wrangler
 
Join Date: Jun 2002
Location: Vancouver, British Columbia
Posts: 8,314
Re: Dylan

<<<-- Originally posted by Marc Betz : For Chirst Sakes Don't you know anything???

You buy it at DRY ICE "R" US

Dopey.

Actually look under cryogenics in the yellow pages.

Marc

: ) -->>>


:)
Thanks. How much is a going price for it, and what amount would fill what kind of volume? Ballpark idea anyway.
Dylan Couper is offline   Reply With Quote
Old November 6th, 2002, 01:48 AM   #18
Regular Crew
 
Join Date: Sep 2002
Location: London, England
Posts: 87
I'll think you'll be disappointed how miniDV renders fog that is fairly even. It looks great on film, but DV has a fraction of the resolving capability of film. I shot some footage up high on a mountain in the cloud layer the amount of noise and banding was terrible. Since then, I've watched for such things in film and even on film, there is a noticeable jump in noise.

Adrian
__________________
Adrian van der Park
VFX modeler
London, England
Adrian van der Park is offline   Reply With Quote
Old November 6th, 2002, 02:43 AM   #19
Outer Circle
 
Join Date: May 2002
Location: Hope, BC
Posts: 7,524
Whatever you do, don't touch it without wearing gloves---it's damn cold! (Frozen carbon dioxide. Ouch.)
Frank Granovski is offline   Reply With Quote
Old November 6th, 2002, 06:20 PM   #20
Regular Crew
 
Join Date: Aug 2002
Location: NH
Posts: 95
Hey Josh

I think its about 10 bucks a pound. It's terrible for making realistic fog or smoke but it is totally inert so you can use it (if you chip it up into small pieces) in drinks or to roll a fog out of a closet or small room during a halloween party etc. It doesn't really fill up an area it just kinda meanders around the floor a bit, but it rolls like fog. The more humid it is, the better it shows up.

It will evaporate (melt) in your freezer so it doesn't have a long shelf life.

Just think, a tray of smokeing shots being handed out to your guests at a party.

Hmmmmmmm

I need a drink
__________________
Marc Betz
Marc Betz is offline   Reply With Quote
Old November 7th, 2002, 07:08 PM   #21
Regular Crew
 
Join Date: Nov 2001
Location: Cape Town, South Africa
Posts: 82
I don't know if this stuff is still around. Back in the '80's on movie sets the SFX guy's used "bee guns". It was a container used by bee keepers to smoke bees. It had a small bellows-type handle that you would pump. It worked great!
__________________
Amacitia Reddit Honores
(Friendship Brings Honour)
Guy Pringle

Silver Reflections
guypringle@yahoo.com
+27(0)83 256 8566
Guy Pringle is offline   Reply With Quote
Old November 7th, 2002, 07:40 PM   #22
Wrangler
 
Join Date: Feb 2002
Location: Cleveland, Ohio
Posts: 1,933
Re: Hey Josh

<<<-- Originally posted by Marc Betz : It [dry ice, aka frozen CO2] will evaporate (melt) in your freezer so it doesn't have a long shelf life. -->>>

To be perfectly accurate about it, your freezer dry ice neither evaporates (changes phase from liquid to gas) nor melts (changes phase from solid to liquid). It sublimates, that is, it changes phase directly from a solid to a gas.

This message brought to you by your local Association for Precision in Scientific Terminology.
__________________
All the best,
Robert K S

Search DVinfo.net for quick answers | The best in the business: DVinfo.net sponsors
Robert Knecht Schmidt is offline   Reply With Quote
Old November 7th, 2002, 09:37 PM   #23
Outer Circle
 
Join Date: May 2002
Location: Hope, BC
Posts: 7,524
If you buy dry ice, put it in a thermo "picnic basket type container." It should last for a few days at least.
Frank Granovski is offline   Reply With Quote
Old November 8th, 2002, 02:33 PM   #24
Major Player
 
Join Date: Apr 2002
Location: Lewisburg PA
Posts: 752
Some fog machines work by vaporizing mineral oil.

Here are instructions for making such a machine:

http://www.iosphere.net/~rheslip/html/body_fog_machine.html

Here is a report on the health effects:

http://www.mindfully.org/Health/Stage-Fog-Risk.htm

My advice is don't mess with the heated glycol.
Peter Wiley is offline   Reply With Quote
Old November 8th, 2002, 05:14 PM   #25
Regular Crew
 
Join Date: Aug 2002
Location: NH
Posts: 95
Robert

I did not want to confuse anyone w/sublimation. It would not have worked in the original post, but the reply was the perfect place to point it out.

It sublimates best in a drink called a fog cutter : )
__________________
Marc Betz
Marc Betz is offline   Reply With Quote
Old November 12th, 2002, 05:50 AM   #26
Retired DV Info Net Almunus
 
Join Date: Sep 2001
Location: Austin, TX USA
Posts: 2,882
africats,

I've seen the bee guns used in some of those "Making of..." shows. I wonder what they put in them...bees and a tiny pack of cigarettes?

It would probably have to be smoke considering how simple they are.
__________________
John Locke
SursumFilms.com
John Locke is offline   Reply With Quote
Old November 12th, 2002, 10:35 AM   #27
Trustee
 
Join Date: May 2002
Location: Barrie, Ontario, Canada
Posts: 1,922
Robert
"To be perfectly accurate about it, your freezer dry ice neither evaporates (changes phase from liquid to gas) nor melts (changes phase from solid to liquid). It sublimates, that is, it changes phase directly from a solid to a gas."

Very true, someone over at the VX2K thread basically told me I was full of it when I said the same thing a few months ago.
Bryan Beasleigh is offline   Reply With Quote
Old November 12th, 2002, 10:48 AM   #28
Warden
 
Join Date: Mar 2002
Location: Clearwater, FL
Posts: 8,287
I've seen cylinders of Nitrogen in hospitals and on industrial sites. Why couldn't it be put into a smaller container with a nozzle, rather than a valve?

Jeff
Jeff Donald is offline   Reply With Quote
Old November 12th, 2002, 11:31 AM   #29
Trustee
 
Join Date: May 2002
Location: Barrie, Ontario, Canada
Posts: 1,922
Disposable cans would never hold that much pressure. The industrial cylinders of dry nitrogen are at approx 2000 psi. My industry uses dry nitrogen as an inert purge to prevent oxidation and as an agent to pressurize and test for leaks. For safety purposes the cylinders are only used with the appropriate pressure regulators.

The disposable cylinders that we buy for cleaning and blowing are cans of liquified gas (refrigerants). much like a tank of propane or butane the liquid propellant boils off and exits the can as a gas. Tip the can and you get liquid. The liquified gases are non toxic and non flamable. If the cans were just filled with a compressed gas , we'd get about one or two shots per can.

Sorry for the tangent. I shouldn't get my shorts in a knot over something so trivial.
Bryan Beasleigh is offline   Reply With Quote
Old November 12th, 2002, 03:44 PM   #30
Wrangler
 
Join Date: Jun 2002
Location: Vancouver, British Columbia
Posts: 8,314
You can get small (45ci-110ci) compressed air/nitro tanks for paintball guns that hold up to 4500psi. They can be regulated down to next to nothing so you can release as much or little gas as you want. I didn't really think nitrogen would create a smokey effect, but I guess?? Anyway, they sell for $100-$400 on average, and are available at a paintball store near you.
If anyone tries this, let us know how it works out
Dylan Couper is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK


DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > Open DV Discussion

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



All times are GMT -6. The time now is 12:10 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network