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Music Video Shutter Tricks


morgstar

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I'm looking to shoot that shutter angle trick you see in a lot of music videos where motion becomes very ... well rigid I guess -- little to no motion blur -- I'm pretty sure it's not just a camera angle it's a combination of shooting with a certain angle and then using the same or slightly different angle in the telecine gate?? Any clues out there??

 

I have no time to test this so please make sure to state if you have definitive experience in this technique! We're shooting 35mm on an Arri 435.

Edited by morgstar
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This is purely a camera trick. it has nothing to do with telecine. Shooting with a 45 or 90 degree shutter will give you that strobe-ish, "Saving Private Ryan" motion. Just make sure that you tell your light meter what shutter angle you are shooting with, or calculate the exposure yourself. For a 90 degree shutter at 24fps, your exposure time would be 1/96. With a 45 degree shutter, exposure would be 1/192.

 

Make sure you have enough light!

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The effect is just what you said, little motion blur. It is created by using a "tight" shutter angle (such as 90 degrees as opposed to "normal" 180).

 

With the shutter angle change, there is an exposure compensation required as well. For example at 90 you need one stop of additional light (or you need to open up one stop).

 

You can create more motion blur by using a "wider" shutter angle. 200 is about as wide an angle that I am aware of (without removing the shutter).

 

Kevin Zanit

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Thanks, Thomas!

 

So, I gather 45° is a more intense effect to staccato the motion than 90°?

We'll be shooting at 25 fps - I was sure there was also a trick in telecine -- I guess not .. thanks for your support -- Is this trick going to effect my lights at all -- will I get strobing if I'm not shooting flicker free everything?! Time to dig out that American Cinematographer's Manual!

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So, I gather 45° is a more intense effect to staccato the motion than 90°?

Yes. It'll be slightly more pronounced.

 

We'll be shooting at 25 fps - I was sure there was also a trick in telecine -- I guess not .. thanks for your support -- Is this trick going to effect my lights at all -- will I get strobing if I'm not shooting flicker free everything?! Time to dig out that American Cinematographer's Manual!

At 25fps shooting under 50 Hz lighting sources, you should be fine at 45 or 90 degrees. However, with 60 Hz non-flicker free lights you will definitely get some weird pulsing since the exposure will be out of phase with the power cycles. It is possible to adjust the shutter to an angle that will eliminate flicker, but it would just be easier to use electronic, flicker free ballasts for your HMIs and fluorescents:

 

A 45 degree shutter @ 25 fps = 1/200 sec exposure, which would show light pulsing at 60 Hz.

 

For example, you would need a 75 degree shutter to shoot flicker free under 60 Hz sources at 25fps:

 

360 / 75 = 4.8, 4.8 x 25 = 120 (1/120 sec)

 

120 / 60 = 2, so 60 divides into 120 evenly meaning you will get two 60 Hz power cycles per frame.

 

Hope that helps!

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I'm in Australia at the moment so 25fps is standard sync frame speed (PAL format) and the electrics are getting the right ballasts together for me now - think I'll shoot some at 45° and some at 90°, just for fun!

 

Any idea what happens if you adjust the shutter angle of the telecine gate?

Edited by morgstar
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.... -- I'm pretty sure it's not just a camera angle it's a combination of shooting with a certain angle and then using the same or slightly different angle in the telecine gate?? Any clues out there??

The telecine trick I think your refering to is when you shoot at slower shutter speeds eg 6fps and then telecine at the same speed 6 fps. The result looks nothing like reduced shutter angle but an extreme motion blur/lag.

G.

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And, hey, the 435 has a shutter that will go all the way to 11.2 degrees, which can look awesome. Also - if you happen to have a 435 ES (electronic shutter) you can change your shutter angle during your shot. Just be sure to have enough light to be able to light 4 stops hotter than you would need at 180 degrees. Go crazy & have fun, that's what music videos are all about for us DPs.

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  • 1 year later...

I have an additional question that might fit in this particular forum. Hopefully someone can help me.

I'm trying to get the "look" of the 45' shutter but I don't have the possibility of actually changing the shutter.

 

So what I thinking might work is - If I shoot at 96 FPS with a 180 shutter my effective shutter speed = 1/192

1/2 x 1/96 = 1/196 and this would be the same as 45' shutter 1/8 x 1/24 = 1/192

 

I hope my math is right. Despite the obvious slow motion effect I think that both would yield the same effect in regards to the amount of motion blur because the shutter speeds are the same.

 

If I sped up the film in Post (subtracted frames) like 75% faster would I get a similar look?

 

If anyone has any thoughts on why this may or may not work or might be able to cite an example of this trick it would be great.

THANKS

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Overcranking (and transferring at normal speed) won't give you less motion blur -- it gives you "normal" looking motion blur on movements that are slowed down. Know what I mean? Motion blur looks silky smooth and normal but all motion is slowed down.

 

Speeding up the motion in post wouldn't effect the motion blur either, since motion was sampled normally in camera. The next closest thing you could do in post is strobe the footage by maybe one frame, giving you normal speed but motion that is, well, "strobed." Not exactly the same look as a fast shutter but can still be effective.

 

You could shoot everything at a faster frame rate, transfer at 24fps, and THEN in post speed the footage back up to restore normal motion. That would give you the same effect as a shooting with a narrow shutter. But it's also kind "going around your ass to get to your elbow" -- you burn a lot of film and spend a lot of time replicating a very simple mechanical effect.

 

If you want to create that "jittery" effect without a slow shutter, try shooting UNDERcranked and have your performers slow down their movement by the same percentage. Human motion takes on a creepy, twitchy look when you do this.

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Actually Michael, he's right. You could shoot at 48 fps, let's say, so that each frame is captured 1/96th of a second, and then remove every other frame to get 24 fps motion with a 1/96th shutter speed -- it would look the same as if you had shot 24 fps with a 90 degree shutter.

 

Same with shooting at 96 fps and removing two out of every three frames to get back to 24 -- you create the effect of shooting with a 45 degree shutter at 24 fps.

 

Trick would be to find a speed-change program that didn't blend frames but just dropped them.

 

Just seems like a ridiculous waste of film to shoot at 96 fps and throw away 2/3's of the material just to get the effect of a 45 degree shutter.

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The telecine trick I think your refering to is when you shoot at slower shutter speeds eg 6fps and then telecine at the same speed 6 fps. The result looks nothing like reduced shutter angle but an extreme motion blur/lag.

G.

 

Am I right in thinking that this was the method used for the stylised future sequences in Wong Kar Wai's 2046?

 

BTW, on imdb the film is listed as having three DPs (Christopher Doyle, Pung-Leung Kwan and Yiu-Fai Lai) http://www.imdb.com/title/tt0212712/fullcredits, does anyone know who shot what?

 

Has anyone every shared the DPing reigns with another DP? Is in normally divided up by INT / EXT, DAY/NITE. Do you attempt to maintain a continuety of look for the whole project or just give in to the inevitable differences and let each man do his own thing. Sorry to slide off topic, but really interested in people's experiences <_<

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You can see this effect in many other of Wong Kar Wai's films as well. I believe Christopher Doyle once said that they shot 6fps in 'Chunking Express' to get another two stops of light in some scenes.

 

The reason Wong Kar Wai used 3 Dops on '2046' is that his shooting always takes ages. I think he shot intermittently for 2 years on '2046'. He works without a script and develops the story while shooting, so it is a very slow process. Obvioulsy it is hard to get such a long committment from any Dop, since they might have signed on for other jobs previoulsy already.

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  • 2 weeks later...
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Actually Michael, he's right. You could shoot at 48 fps, let's say, so that each frame is captured 1/96th of a second, and then remove every other frame to get 24 fps motion with a 1/96th shutter speed -- it would look the same as if you had shot 24 fps with a 90 degree shutter.

 

Of course you're right; I thought Duffy meant speeding up 24fps footage in post, not speeding up overcranked material.

 

It was late, and I probably didn't read the post correctly!

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  • 11 months later...
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......Same with shooting at 96 fps and removing two out of every three frames to get back to 24 -- you create the effect of shooting with a 45 degree shutter at 24 fps.

 

Just a minor math correction, I think one would have to remove three out of every four frames to get back to 24 frames, and to be Kodak's best friend as well. :D

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