Shutter speeds for Slo-Mo

[C.B. Lorch]

I've been reading up on shutter angle and frame rates since our Red is my first experience with being able to Over/Under crank. Lots of good content about angle vs. degrees etc. , but not much about practical applications such as...

How can I use the shutter to reduce motion blur when over-cranking for intentional slo-mo use. I seem to get a decent amount of blur with the default shutter speeds at various frame rates.

Thanks

 

[Brandon Fraley]

I'm not sure I understand the question. If your getting too much blur, then make the shutter speed shorter.

 

[G-unit]

If you want to reduce blur, increase "shutter speed"

 

[Brian J.M. Rytel]

Step 1: Double the frame rate and set the shutter speed to this number(this is a digital camera) ie 60fps:120/th second.

Step 2: Figure out your light's frequency and adjust the speed as not to cause interference.

Warning: I'm not a cinematographer, and not particularly familiar with the symptoms of certain lighting configurations on high-framerate imagery.

Note: Using an angle description complicates the mathmatics a bit, as the angle is a percentage of each frame, which you then have to multiply by the framerate, it is much easier to use nth/second, as it is based on time rather than degrees=percentage of frames etc. You'll have cleaner easier results with shutter speed. *Ignore this if you have learned and can calculate angle without a piece of paper.

 

[Bilal Lashari]

Relationship between Shutter and Frame Rate

Relationship between Shutter and Frame Rate

Shutter Speed = (Shutter Angle) / Frame Rate

At 180 degree shutter shutter angle is 1/2 (180/360)
At 24fps, shutter speed = (1/2) / 24 = 1/48

If you shoot high speed, say at 96fps (4 times or 2 stops), shutter speed will be 1/192

Compensate the same amount of stops on the shutter as you would on the frame rate. As long as shutter SPEEDs are the same any combination will produce similar motion blur. So basically no matter what frame rate you shoot at, for example 96fps, if you are playing it back at 24fps, the shutter speed/motion blur will be the same as shooting on 24fps, if the exposure is the same, as the digital camera will compensate through the shutter. To have less motion blur the shutter speed needs to be faster, so instead of 1/192 at 96fps try 1/384 or 1/768 at 96fps. You will need alot of light for such combinations, as you are cutting down stops from both ends, shutter and fps.

Hope that helps.

Thanks
Bilal Lashari
www.blashari.com

 

[C.B. Lorch]

That does help. Thanks.

It's basically what I had assumed from some limited past experience with using a bit of shutter in shooting sports with video at 29.97. And totally understood on needing the light.

In your example speeds you went with shutter speeds that kept the shutter angle at 180. Is that imperative, or could you use higher shutter speeds that do not end up with 180 shutter? What does this do to your image?

Thanks,

 

[Greg Ephraim]

hey bilal!!! this your first post?
good to see you on here

Shutter Speed = (Shutter Angle) / Frame Rate

At 180 degree shutter shutter angle is 1/2 (180/360)
At 24fps, shutter speed = (1/2) / 24 = 1/48

If you shoot high speed, say at 96fps (4 times or 2 stops), shutter speed will be 1/192

Compensate the same amount of stops on the shutter as you would on the frame rate. As long as shutter SPEEDs are the same any combination will produce similar motion blur. So basically no matter what frame rate you shoot at, for example 96fps, if you are playing it back at 24fps, the shutter speed/motion blur will be the same as shooting on 24fps, if the exposure is the same, as the digital camera will compensate through the shutter. To have less motion blur the shutter speed needs to be faster, so instead of 1/192 at 96fps try 1/384 or 1/768 at 96fps. You will need alot of light for such combinations, as you are cutting down stops from both ends, shutter and fps.

Hope that helps.

Thanks
Bilal Lashari
www.blashari.com

 

[Stuart English]

Red one

Red one

Shutter Speed = (Shutter Angle) / Frame Rate

At 180 degree shutter shutter angle is 1/2 (180/360)
At 24fps, shutter speed = (1/2) / 24 = 1/48

If you shoot high speed, say at 96fps (4 times or 2 stops), shutter speed will be 1/192

Compensate the same amount of stops on the shutter as you would on the frame rate. As long as shutter SPEEDs are the same any combination will produce similar motion blur. So basically no matter what frame rate you shoot at, for example 96fps, if you are playing it back at 24fps, the shutter speed/motion blur will be the same as shooting on 24fps, if the exposure is the same, as the digital camera will compensate through the shutter. To have less motion blur the shutter speed needs to be faster, so instead of 1/192 at 96fps try 1/384 or 1/768 at 96fps. You will need alot of light for such combinations, as you are cutting down stops from both ends, shutter and fps.

Shutter Speed = (Shutter Angle) / Frame Rate... well that's true for a film camera, and is also true if you set the RED ONE into RELATIVE shutter mode.

However as its default the RED ONE maintains the shutter speed at all frame rates. So rather like shooting with a DSLR, you should just choose a shutter speed appropriate to your application.

 

[christiansprenger]

quick and dirty... if you want to maintain a consistent motion blur (and you are shooting at 180 degrees) - take your new frame rate, times it by two.

24fps x2 = 48 or 1/48th.

60fps x2 = 120 or 1/120th.

96fps x2 = 192 or 1/192nd.