Bert
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Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
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Flash Suppresion?
I have been involved in several movie and video SPFX projects recently. Some of the shots involve actors rigged with bullet hits- And the commercially
available products we have access to have had far more flash than I like.
I've got some literature on reducing muzzle flash in artillery propellants, and a good bit on lowering heat of explosion for blasting in explosive
atmospheres during coal mining. Bullet hits tend to utilize primary explosives with various adulterants intended to phlegmatize them and/or increase
gas output... A rather different kettle of fish. Plus they shouldn't release heavy metals or other dangerous products, a large scene can run to dozens
or even hundreds of hits. Typical explosive loadings for these "body hits" are 40 to 160 mg, some larger devices are occasionally used.
I'm reviewing patent literature and generally looking for any info I can find on visual flash reduction or (hopefully) elimination. Any thoughts?
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
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2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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quicksilver
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The "cooling effect of sodium chloride was one of the contributions of some "Soviet" patents (Cold War era material). TTBoMK - take a look at large
Navel systems cooling methods patents and the cooling effects of triple based smokeless powder formulations: you may find what you're looking for
there. The original concept of nitroguanadine addition in a powder was for cooling agenda as I understand it.
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Bert
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Posts: 2821
Registered: 12-3-2004
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Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
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Yes, good old Sodium chloride features in a lot of permissible explosives. Naoum mentions that use along with some other gun propellant flash
reduction techniques from around WWI.
I've actually got some guanidine nitrate to hand, left over from experiments with blue strobes a while back. I recall the rational behind the old
Jettex propellant formulation included a low exhaust temperature too-
Another desirable feature in a bullet hit would be as little smoke as possible. Just doesn't look right to have your shot actors smoking "but not
inhaling". People might mistake them for Bill Clinton.
[Edited on 31-3-2011 by Bert]
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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