My friend Sam has tasked me with helping to develop special effects for his upcoming film, Saint Mark's Hooker. Today, we discussed techniques for shooting a full-on shotgun blast to the chest.
I didn't know anything about making bloody explosions before I did my research, but now I have a working knowledge of the techniques involved and the ideas have started to flow. There are a lot of good resources on the web that I'm compiling here to make the search easier for anybody on a similar quest.
The first (and probably the cheapest) method of making a fake gunshot that I found is from IndieMogul. In this video Keir MacDonald shows us how to put a condom full of fake blood under a target's shirt, and use a washer attached to fishing line (if you're inside) or black thread (if you're outside) to snap the condom, making the blood burst out.
In Keir's method, you might need to cut the shot so it begins when the washer exits frame, or else it breaks the illusion.
In that method the blood is basically getting *pulled* out of the actor, rather than pushed.
I was curious about methods where the wound actually explodes (no cutting to mid-explosion required), as with squibs.
Real squibs are explosives, which are dangerous to use and expensive (and you "legally" need a licensed pyrotechnician to help you do them). But there are also pneumatic, or air-powered squibs.
I found instructions on how to build a pneumatic squib here.
While it might be peachy to build a fancy machine like that from scratch, I figure it might be a bit infeasible for our production to buy all the right mechanical parts and put them all together like that. We're filmmakers, not mechanics.
So I was looking for more novice-friendly air-pressure-powered blood-propulsion mechanisms
I found this video by FilmRiot (Posted just yesterday! Lucky me!).
It shows how to do a number of awesome blood effects using an air compressor bought at the store (for bike tires) some surgical tubing, and some clever looping and arranging of the hose.
It's probably the most comprehensive source.
After I watched that, I was looking for a version of the "sprayed" blood system that was both labor-saving and DYI-cheap. (The best of both worlds between the indiemogul and filmriot ideas)
I didn't quite find what I was looking for but I found this video hidden in the corners of youtube.
Here a friendly lad from Oceania shows us an imperfect (doesn't cut a hole in his shirt) example of doing the blood splatter using only a bottle-as-bellows and some surgical tubing.
So now I'm theorizing about a device that uses the same hose setup that filmriot used on Stark, but powered by a hand-pump, or maybe by a person blowing into the tube (pygmy blow-gun style) to fire the blood.
I don't know what method we'll use. Maybe we'll spring for a compressor, maybe our friend can build us a valve, maybe the fishing-line and condom idea is the right way to go. Whatever we decide, the answer can be cobbled together from what I've learned in these videos.
Bless the digital age. This wouldn't be possible without it.