Shutter Speed In Relation to FPS

T

tommygdawg

Well-known member
Howdy ya'll

So I know the basics: you typically want to double your framerate with your shutter speed. The most common is 24fps, 1/48th shutter. My question is, why do you need to increase your shutter speed for fast frame rates? How come if you're shooting at 60p, they say you should increase your shutter speed to 1/60th? Any thoughts?

Thanks!
- Tommy
 
if you're shooting 60fps, the 180 degree rule would put the shutter at 1/120th, not 1/60th. It's all about motion blur, and with the 180 degree rule (entails all the way back to film cameras I believe?) you shoot double shutter to your frame rate, however... there are shooters out there, like me. Who shoot primarily sport and prefer to have higher shutter speeds to eliminate motion blur completely, there is a threshold where the footage get's to a point with the shutter speed, normally around 1/2500th of a second before it looks 'fake & sped up' with 50/60fps, I haven't shot any higher frame rates.

I still use the 180 degree when I am shooting narrative / interviews.
 
It is not physically possible to shoot a shutter speed slower than your frame rate. Slowest possible is equal to frame rate.
 
LiamR said:
if you're shooting 60fps, the 180 degree rule would put the shutter at 1/120th, not 1/60th. It's all about motion blur, and with the 180 degree rule (entails all the way back to film cameras I believe?) you shoot double shutter to your frame rate, however... there are shooters out there, like me. Who shoot primarily sport and prefer to have higher shutter speeds to eliminate motion blur completely, there is a threshold where the footage get's to a point with the shutter speed, normally around 1/2500th of a second before it looks 'fake & sped up' with 50/60fps, I haven't shot any higher frame rates.

I still use the 180 degree when I am shooting narrative / interviews.
Click to expand...

My bad, that was a typo, I meant 120th for shutter speed at 60fps.

Razz16mm said:
It is not physically possible to shoot a shutter speed slower than your frame rate. Slowest possible is equal to frame rate.
Click to expand...

Right, but why can't I shoot 60 frames a second at 1/60th of a second shutter speed?
 
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obligatory picture (i love posting this)
 
tommygdawg said:
Right, but why can't I shoot 60 frames a second at 1/60th of a second shutter speed?
Click to expand...

You can. Whilst film cameras don't generally go beyond a 200 degree shutter digital cameras can and often do have a 360 degree "open" shutter. Sometimes I'll shoot 270 degree shutter to gain an extra half stop. A 360 degree shutter will increase motion blur and look more like video than film, but it has its uses.
 
tommygdawg said:
Howdy ya'll

So I know the basics: you typically want to double your framerate with your shutter speed. The most common is 24fps, 1/48th shutter. My question is, why do you need to increase your shutter speed for fast frame rates? How come if you're shooting at 60p, they say you should increase your shutter speed to 1/60th? Any thoughts?

Thanks!
- Tommy
Click to expand...

It's really not a question of "typically wanting" to do anything; it's just a common shutter speed for 24 fps.
 
J Davis said:
Moviecam_schematic_animation.gif


obligatory picture (i love posting this)
Click to expand...

was waiting for someone to post this

tommygdawg said:
My bad, that was a typo, I meant 120th for shutter speed at 60fps.



Right, but why can't I shoot 60 frames a second at 1/60th of a second shutter speed?
Click to expand...

You can, no one's going to call the police on you for shooting at 1/60th of a second. But, as has been mentioned, film is traditionally shot with a 180 degree shutter-- many say they like the aesthetic better, personally I think it's just because that's the way it was always done-- but regardless, the look of a 180 degree shutter is usually associated with high quality productions. Maybe that's changing, and of course there are always reasons to switch to a different shutter angle if you need to.
 
I have a question which has puzzled me for a long time: I once owned a Sony PD 150. I remember, I was able to change the shutter speed to 1/4 of a second and every motion got nicely blurred.
At that time, I did not know anything about video.
Today I want to get the same effect with the Epic, but can not imagine, how that would work? I can not have a 1/4 sec exposure in 24 frames/sec. Maybe in 4 or so frames per sec. As far as I understand, changing shutterangle on a digital camera is the same as changing shutterspeed. Movie cameras did not have shutterspeeds adjustments, only FPS. If I run 4 fps, and play it at 24 fps, movments are far too fast and have a timelapse effect. Which is similar. Any suggestions?
 
dwcdv said:
I have a question which has puzzled me for a long time: I once owned a Sony PD 150. I remember, I was able to change the shutter speed to 1/4 of a second and every motion got nicely blurred.
At that time, I did not know anything about video.
Today I want to get the same effect with the Epic, but can not imagine, how that would work? I can not have a 1/4 sec exposure in 24 frames/sec. Maybe in 4 or so frames per sec. As far as I understand, changing shutterangle on a digital camera is the same as changing shutterspeed. Movie cameras did not have shutterspeeds adjustments, only FPS. If I run 4 fps, and play it at 24 fps, movments are far too fast and have a timelapse effect. Which is similar. Any suggestions?
Click to expand...

The slow shutter on a PD150 was a digital effect.

You are wrong about movie cameras. You can change the shutter. It's where the term shutter angle comes from.

http://en.wikipedia.org/wiki/Rotary_disc_shutter

If you shoot digitally at 4fps for a 24p project you need to change the settings on the clip so that your NLE knows what speed to play it back. In FCP you can use Cinema tools to conform the footage with the correct fps playback setting before you import it, in PP you choose modify/interpret from within the project.
 
Liam Hall said:
The slow shutter on a PD150 was a digital effect.

You are wrong about movie cameras. You can change the shutter. It's where the term shutter angle comes from.
Click to expand...

Great, thanks Liam!
I was always wondering, how that would be possible.

Well, no, on 35 mm cameras, there was no shutterspeed adjustment, shutterangle only. (I was using for long time a Mitchell and the only shutterspeed setting (other than the shutterangle slider on the right side) was when you used a timelapse controller (mine was Lynx Robotic).

I will try your suggestion, so you mean, I could mix different fps shots and play them back with 24p without seeing the difference? That sounds interesting.

Thank you
 
Yes, you can mix and match recorded frame rates with digital video in much the same way you could with film.

And just for clarity:
Shutter speed and shutter angle are essentially the same thing. They are both used to describe the length of exposure time. Shutter speed is commonly a term used in video and photography, shutter angle, as you are aware, is more commonly used with movie cameras. The only real difference is shutter angle is relative to frames per second.
 
Thank you for explaining to me... sure you are right... shutter speed refers more to a still image exposure!
 
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