Quite often, even when blank firing weapons are used on set, the muzzle flash doesn’t read, presumably due to the shutter timing on the camera just happening to be closed during the flash.  So even after all the logistics involved with having an armourer on set, you still find yourself adding, or at least enhancing them in post.

One way to add them is by using software that generates various styles and looks of gunfire procedurally, one such example is HitFilm that includes gunfire and muzzle flash effects.  There’ll be parameters for randomising details like colour, blur, glow etc and making it more chaotic and in no time at all you’ve got something that looks bang on.  There will be occasions though, when no matter what you try it’s just not working for you, maybe it’s the lighting, maybe the angle of the gun in relation to the camera or maybe you have so many shots in there that you’re beginning to see the same patterns again and again.  This is when it’s good to have a few more tricks in your bag.

One such trick that I’ve used in the past is the hand drawn technique.  Sure it takes longer than a plugin and you certainly wouldn’t want to hand draw all the muzzle flashes in a film like ‘Saving Private Ryan’, but vfx is all about having as many tricks in your bag as you can fit and once you’ve drawn a few dozen, you can call it a library that can be called upon for future work.

It starts with reference and my favourite for modern weapons is ‘Black Hawk Down’.  Not only is there lots of gunfire in it, but there’s also a good variety of handguns, rifles, machine guns and even chainguns.  Don’t forget youtube, there are some insane videos out there of all kinds of weaponry doing their thing.

Step through the reference, frame by frame until you find a muzzle flash you want to use and literally copy it by hand drawing it in Photoshop.  You want the drawing to be loose, it can be a bit scribbly because you’ll be blurring it and glowing it up and what you’re after is some of that chaos that happens at the end of a gun when it fires.  If you’re not happy with it, just undo it and go again or even better work on a big canvas and fill the screen with attempts, just give yourself some space around them so you can cut them out.  For now you’re just painting white on black, the colour will be added in later.

When you have a few that you’re happy with, crop them one at a time until the frame is only slightly bigger than the muzzle flash itself.  Save them to your ‘library’ and name them something that makes sense to you so you can quickly find them for future shots.

Fire up After Effects (I suspect this technique could easily be achieved in Premiere and Final Cut Pro too) and load in your shot of ‘dude firing gun’.  Bring in your muzzle flash images and position them where and when they need to be.  More than likely they’ll only be on screen for one frame.  Give the muzzle flash a glow and choose a yellowy/orange colour for the effect; maybe try out other colours if the weapon is futuristic or the shot’s lighting is unusual.  Make sure the blending mode for the muzzle flash image is set to Add.

Add some blurs; these can be regular blurs, directional blurs or zoom blurs (for zoom blurs, set the zoom centre point to the end of the guns barrel), you can even animate the muzzle flash on the frame before and after the muzzle flash and then turn on motion blur which works really well if the gun itself is heavily motion blurred.

Here’s a few muzzle flashes that I created which I recently used on a feature film that's currently in cinemas around the UK.  Feel free to use them in your movies if you like, just drag them from the website or right click, save image as.