Home of Professional Cinematography since 1996
Capturing Gun Flashes
>Some of you have probably done a lot more gun shots than I (on film that is), hence the reason for this post.
>In the recent action footage I did, the director was sometime disappointed because not all the gun flashes show up on the film. Of course we all understand why, knew about this problem beforehand, but also realize we are pretty much powerless to do much about it.
>Machine guns and shot guns are usually all right because they have a longer lasting flash. Even though the gun guys are using special gunpowder mixes to cause longer duration flashes, handgun flashes often happen while the shutter is closed. Even if one were to do 10 takes of each shot there is no guaranty that it would work for all gun shots. Especially in a shot where the actors fires multiples shots, the chances of getting them all on the film are reduced even further the more shots are fired. It's really a toss of a coin. It sure looks odd when someone fires and you can see the recoil but no spark.
>Now some know it all editor told the director that using slower shutter speeds would help. Gee, some rocket scientist there, quick call the Nobel society. We were already shooting with the shutter at 180. Reducing the frame rate in order to slow shutter speed, already at 180, would diminish the chances equally, not to mention the really fast pace action shots we would get by undercranking. Old Chaplin meets Rambo :-).
>Anyway I told the director that this editor should stick with editing but.... that I belonged to this really good and intelligent e-mail group and that I would submit the question.
>Using Panavision cameras with a 200 degrees shutter would offer a marginal improvement but that would not be the solution to all.
>The guys in post-production say it is a relatively simple, and commonly done, task to take a gun flash from one gun shot and copy it to another where there is no flash. That sound all right but $$$.
>I'd appreciate your input about this matter.
>Daniel...after 10 years of low budget features and half a hearing loss later...their is an answer. Creative Efx, in San Fernando CA., makes a neat line of guns which take electronic ammo charges, which are safe at any distance, even less than a foot, and produce a long duration flash. You don¹t need a pyro guy, or a gun expert, and they look good.
>The trade off is that the charges cost about $4 apiece, and not every gun type has been modified, and their is no chamber or moving parts which limits close ups...
>Test-test-test!!! The armorer should be able to provide loads that will give you the flame effect you want. Remember the type of weapon will influence what type of muzzle flash you get.
>M-16's and MP-5's all use the "Hollywood" flash suppressor (a small "restrictor") in the barrel that increases the gas pressure so that the weapon will cycle with the lower pressure blanks. This would tend to reduce the amount of muzzle flash you get.
>There are many specialized weapon loads out there...so consult with your fav (licensed) armorer. Also, playing with the shutter angle and overcranking might give you some interesting effects.
>And remember safety for everyone involved. Especially with the talent and safe directions for pointing the muzzles of the weapons. The Brandon Lee incident was a tragic and senseless accident.
>What you were seeing was the gun flashes running slightly out of phase with the shutter in the camera.
>The same thing happens when you see HMI "flicker" with magnetic ballasts and an off speed generator or camera (or if you have really bad karma that day, BOTH.)
>When it is only slightly out of phase it is seen as a slow darkening and then lightening of the lamp's apparent exposure on the film. When it is more out of phase, it gets brighter and darker more quickly and appears to be more of a "flicker."
>The rate of cycling is dependent on the "beat frequency" between the two, the camera frame rate and the flashes per second of the gun barrel flash of the HMI flash.
>You either need longer duration gun barrel flashes, or sync the flashing to the shutter speed.
>Bill Bennett, Los Angeles
>Guns with electronic flashes: Creative Efx 818 365-0655 Ammo for electronic guns: Edolmar Eng 818 365-9208 haven't used them, but have seen it on film and they work well, with a long flash. No pyro guy, permit or fire officer needed. Only works with modified guns, currently only 9mm and a few others. About 4 bucks a pop, not including gun rental...
>Howard Wexler Los Angeles
>If they exist, then the folks that would have them is Stembridge gun rentals in Glendale (818/246-4333). Syd Stembridge has done just about every imaginable type of specialty guns for movies.
>Has anyone ever tried using radio to give these signals ? All you would need would be an opto slotted disk mechanically connected to the output shaft and two tone generators (one for open, one for closed). On a very small set you could get away with using 50.5 license free equipment (like a baby alarm or kids walky talkies). The receiving equipment would simply be a small unit that receives the tones and interrupts the firing of the weapon when the shutter closed tone is heard. any delay in the action of the guns could be compensated simply by rotating the disk on the camera so that the shutter open signal could go out before the shutter really is open.
>As far as interrupting the gun goes (and I am hope noone considers this to be off topic) how did they interrupt the machine guns on first world war fighters ? This is a similar problem to ours (except that their propellers had way smaller blades than our shutters).
>Obviously, the solution is the new AatonTCGun. A very accurate timecode generator on each gun, jam-synced to the camera, locks the gun's firing to shutter-open points on any Aaton camera.
>In addition, a timecode-controlled limiter can drop the record level of any digital recorder for the duration of the gunshot (tho many recordists prefer analog for guns).
>This circuit was originally designed for the Chinese military, when the Chinese Documentary Studios purchased 40 Aatons some years ago.
>(Actually, I would think that these guns could be wireless by now, each with a little receiver.)