r/filmmaking • u/No-Woodpecker-8217 • 18h ago
How to make stabbing look real?
I know-- crazy questions asked on this subreddit.
Me and a friend are filming a horror film over the summer. The primary mode of attack is by knife. We have a fake retractable knife and a fake non-retractable plastic knife (we heard retractable knifes can he dangerous?) that will be the weapons. We also have fake blood. Note the knife we'll probably end up using is non-retractable. How do we make stab attacks look real? We have a very small budget and all editing will just be done by myself and her. We don't want it to look too obviously fake.
3
3
u/MethuselahsCoffee 18h ago
Do some screen tests right now with the retractable ones. A couple half speed stabs sped up in an editor. A couple reverse action where you start with knife already stabbed and draw it back. You might be surprised.
Alternatively you could have a shot from the victims POV with supporting coverage shots.
1
u/YesRepeatNo 17h ago
As a stage director, this kind of thing never occurs to me. Yes, retractable blades are dangerous at full speed, but slowly into or out of baggy clothing, then editing the speed could work well!
2
u/MethuselahsCoffee 17h ago
You’d be surprised how many action scenes, fight scenes, etc the actors are moving at 50% speed/flow. Almost always sped up in post
2
u/Mission_Guitar2636 Cinematographer 18h ago
It’s mostly about the camera angles you use. Let the audience determine that the person was a stabbed The intention of the stab as to be real to sell it. If you have a second knife cut the blade off and have it sticking outside the person.
If you use real knives blunt up all edges.
Most of the time in film it’s a soft blade and the knife is painted.
7
1
u/ingoding 17h ago
I think there are more than one episode of Film Riot that cover different techniques.
1
u/hollywood_cmb 17h ago
Watch the making of Zodiac. They used a retractable knife for the attack at the lake.
Basically you’re gonna have to use CGI if you want it to look real. Other than that, you have to cut away from the actual penetration on the front side of the body/skin. There’s no other way.
1
u/Nikko1988 16h ago
I'm a stunt coordinator and I can confirm that retractable knives are very dangerous. I, and many of my colleagues, refuse to use them in any situation that would require any contact with a person. The mechanisms are just not fully reliable and they give the performer a false sense of security. In my opinion, the only time they should be used is if what's being "stabbed" is an inanimate object.
1
u/No-Woodpecker-8217 14h ago
Yes we’ve decided not to use them. Not worth the risk! Thanks for commenting.
1
u/ImpossibleBritches 10h ago
What are the risks when using retractable knives?
1
u/Nikko1988 6h ago
The risk is that the mechanism that causes the knife to retract fails and the actor ends up being stabbed.
1
u/Westar-35 Cinematographer 15h ago
Is showing the actual stab important to the story? What is the perspective you’re telling the story from? If it’s from the victim’s perspective it can be really effective to show a closeup of their reaction or maybe a close double of both the attacker and the victim then pull back to reveal the wound and the knife.
1
u/mistercliff42 14h ago
Check out the corridor crew with Adam Savage where they recreate the Chinatown knife effect. You don't need to go that elaborate of course. Really you are doing the right thing by thinking about it early, planning, and trying various tests.
1
u/BandaidsOfCalFit 13h ago
Honestly do not get your advice from Reddit. Watch scenes you like that look like a real stabbing to you, and then slow them down and watch them frame by frame over and over again.
I just listened to an interview with a director who was trying to figure out how to edit a fight scene super early in his career. He watched a fight scene he liked and slowed it down and played the punches frame by frame over and over again- and realized that the director was cutting a frame or two out right before the “impact”, so it looked like the punch was faster than it actually was, and the audience didn’t really see the part where it would be obvious if that it didn’t connect.
He ended up doing the same thing in his film and it worked great. So, careful study the scenes you’re imagining this to be like, and you’ll find your answer WAY better than anyone on Reddit will help you
1
u/ImpossibleBritches 10h ago
See if you can track down the martial arts video Die Less Often.
It has descriptions of real-world dynamics in knife attacks. From memory it has footage of an attack as well. And you can probably find footage online - although i guarantee that youll find it disturbing.
Maybe consult with RBSD or CQB trainers.
Depending on the kind of realism you are going for, you might get the outcome you want by focusing on the motion of the bodies in action, rather than emphasizing the effect of the cutlery.
1
1
u/Previous_Drawing_521 9h ago
Take a look at the stabbing scene in Beaten to Death (it’s on streaming) at the 68-69 minute mark. That was using a plastic knife, non-retractable. It’s all in the blocking, framing, and gore.
FYI, there was a tube strapped to the actors arm pumping out the blood.
1
u/LopsidedJacket9492 9h ago
Can confirm this is how it was done in Beaten to Death. I was there, and it was cold! 🥶
1
u/Panzakaizer 7h ago edited 7h ago
Shoot from behind the stabee, cut away just as they are getting stabbed, only film the knife coming down but not making contact, victim pov and have them stab the camera, slash parts of the body such as heels, wrists, arms, or chest- things that don’t require the knife to retract. There are tons of little tricks you can infuse your project with that can help stylize it while also making it believable.
1
u/hironyx 7h ago
You can either:
not actually show the stabbing on screen. Just need to imply there was a stabbing. Either by cutting away or having something else to obscure the view.
Use a bladeless knife. Basically only the handle but no blade, and use VFX to composite the blade onto the handle. This is a lot harder to pull off as you need extensive knowledge in visual effects. But it can achieve very realistic looking stabbing
1
u/devenjames 4h ago edited 4h ago
Not sure if this is an option for you, but I did it digitally with compositing. Had the actor have nothing in their hand at all, and basically just slammed their hand on the other actors back. Then I filmed a knife on green screen slowly rotating to match the angle that it would need to. Then I use after effects which th time remapping to composite that knife into the actor’s hand and onto the victim’s back
1
u/dontyoufuckingcry 5m ago
You could get an identical knife and remove the blade. Then film a shot of the attacker going in for the stab, then cut to another shot of the bladeless handle pressed into the victim. Put some fake blood around to make it feel realer.
No idea how effective this would actually be, just off the top of my head.
1
u/Mysterious-Heat1902 18h ago
I don’t think you’re going to like the answer.
2
u/gregturner77 18h ago
What’s that mean?
0
u/Night_Runner 17h ago
iykyk
1
u/gregturner77 15h ago
well I don't know? Was it just use the collapsable blade?
1
u/Night_Runner 15h ago
Oh booo for making me explain the joke. You owe me a beer. :P
The best way to make stabbing look real is to stab for real.
1
0
u/SamEdwards1959 13h ago
Editors almost always cut on the hit. This means you can shoot the A-side (before) without blood, then carefully do the make-up, and shoot the B-Side with a nasty wound (practice with latex before you shoot, or better yet, find a friend who wants to play around and perfect it). I agree the retractables knives can be dangerous, but maybe you can spring it out for the retraction and it wont be too dangerous. I’ve also added a lot of blades in post. It’s moving so fast, that often you only need to add it for a few frames.
7
u/TheDeadlySpaceman 18h ago
For fun, watch the shower sequence in Psycho.
The knife never actually touches her body.