Originally Posted by
TheBennyB
Gary, you can somewhat achieve this same effect for a artillery shell hitting in the ground. Grab a small funnel, hook up some nitro fuel line to the small end and fill the open end with talc, cover loosely with saran wrap or foil. Bury the funnel just to cover the up end (saran wrapped) and attach the other end of the fuel line with some compressed air. Voila, smoke and dirt go a flying. Only conern with this is getting all that junk in your IR tube and apple if your battling and some goof decides to set it off while your tank is literally right next to it. Could make for a nice effect on one of your next videos. Here's the funnel size you'd be looking at. Maybe you'd have something like it at work.
http://store.rc4wd.com/Hydraulic-Oil-Funnel_p_2973.html
That's similar to what the effects industry has been doing in films for years. They call 'em air cannons and are used when they don't want flames from a pyrotechnic effect. Every one here has seen them in use, any of the mortar hits where someone went flying in SPR, Band Of Brothers or The Pacific is a huge air cannon. They place them in the ground, back fill with debris, set a mini trampoline in front of it and the stunt dude pops onto the tramp sending him in the air as the cannon blows all the foam rock bits.
My son and I did some tests last year using a small plastic chamber, 91% alcohol and a grill igniter. We carved out a styrene insulation panel to look like a destroyed building with shell hits, laid it flat and covered it with ash from the grill to look like concrete. Set the
JS-2 up in front of it (on it's side) and rotated the turret while firing the igniter. It blasted out a nice cloud (I thought I posted it here), but in the end, it's too fast to look good on video as is.
The big thing for explosion effects with miniatures is to be able to over crank the film. Film travels at 24 frames a second, if you over crank the speed while filming to a higher rate, when played at 24 frames, it gives a nice feeling of weight and size. Puppets, X wing fighters, etc are all done that way.