C100: Shutter speed for slow motion

B

benjaminwraae

Member
Hey I´m going to shoot some slowmotion on my c100.

I´m shooting 50i (Because my project is 25p 1/50 Shutter) But shall i change my shutter setting? Or keep it at 1/50. I´m slowing the footage 50 percent.

And i´m editing in fcp 7. Does anyone knows a program that can do the conversion instead of fcp 7

Thanks in advance.

Benjamin
 
Why change to degrees if you understand the seconds system?

For a filmic motion you use 1/50s for 25p. There motion blur in moving subjects. When I want to slow footage down, I use a higher shutter speed to make the frames more distinct and frozen and more crisp overall. I use 1/120s and up. The higher better for slowmotion but 1/120 is very high for most applications, only go higher if the subjects are moving extremely fast.
 
In this case i think i´m going for at natural look for the motionblur. But I will experiment with raising the shutter just to see the effect!

So the way I understand it I´ll get the the same filmic motion you use 1/50s for 25p by using a shutter of 1/50 even though I record in 50i and slow the footage down?
 
Ebrahim Saadawi said:
Why change to degrees if you understand the seconds system?

For a filmic motion you use 1/50s for 25p. There motion blur in moving subjects. When I want to slow footage down, I use a higher shutter speed to make the frames more distinct and frozen and more crisp overall. I use 1/120s and up. The higher better for slowmotion but 1/120 is very high for most applications, only go higher if the subjects are moving extremely fast.
Click to expand...


This is is done for a very simple reason. If you are changing frame rates and are at 1/48 at 24p....then change to 60i....you will still be shooting at 1/48. That is not normally the desired functionality.

By changing your shutter angle to degrees you bypass the need to adjust your shutter from the changing frame rates. So....by setting it at 180 degrees....when you change from 24p to 60i your shutter remains analogous.

Why add a step to the process if you don't need to? There is also a sentimental, traditional element for me as its a traditional cinema format to work in. It's also much easier if you are in an event environment.

Hope that helps.
 
Last edited:
So I see my question was formulated pretty bad :)
What i mean. If I like the motionblur to look the same way as if i shoot 25p and shutter 1/50. What should I set my shutter to when shooting 50i and slowing 50 percent doen in post?
 
benjaminwraae said:
So I see my question was formulated pretty bad :)
What i mean. If I like the motionblur to look the same way as if i shoot 25p and shutter 1/50. What should I set my shutter to when shooting 50i and slowing 50 percent doen in post?
Click to expand...
1/100. That's why RealWorksMedia wrote that you should change to degre (in this case, 180)...doing so, whatever framerate you select, you will have the same motion blur.
when shooting 50i at 180 degre, the camera will automaticaly set your shutter to 1/100.
 
From what I understand about frame rates, the camera is not meant to shoot slowmotion, it's done by shooting at 50i (=25 progressive frames) then interpolating (creating) the actual extra frames in post production. 50i is 25p, it's the same file in the C100 with just a metadata flag difference between the two, so using the 180 degree shutter rule shooting in 50i you should use 1/50s, and if you set the camera to 180 degree I believe it will choose 1/50s not 1/100s (please someone confirm or correct me). Now when we take into account that you are going to create extra frames in post, basically doubling them, then using a 1/100s shutter would make sense.
 
Thank you very much everybody. I will go with 1/100 then.

Anyone knows a smart simple program, that can convert to 50i to 25p (Slowmotion)
I edit in fcp 7 - but it´s too old and poor to do it.

Regards,
Benjamin
 
benjaminwraae said:
Thank you very much everybody. I will go with 1/100 then.

Anyone knows a smart simple program, that can convert to 50i to 25p (Slowmotion)
I edit in fcp 7 - but it´s too old and poor to do it.

Regards,
Benjamin
Click to expand...

Converting 50i to 25p doesn't make it slow motion. 50 fields (50i) equals 25 frames (25p).

What people are trying to do with interlaced footage is to convert 50i to 50p. That is: turn your half resolution fields into actual frames by interpolating the footage. Once you have 50p or 60p you can turn this into slow motion in a 24p or 25p timeline.

But you shouldn't have to do an extra conversion step: just go with a modern NLE like FCPX ($299 or something).
 
I record the 50i on the ninja blade, using the 180 degree. Then in premiere pro cc i drop it on the 25p timeline and set the speed to 50%. Results are pretty good i must say. No conversion needed.
Nice thing of recording 25p and 50i on the ninja is that you can actually better determen what was shot in 50i and what was in 25p and the bitrate is way better ofcourse. The avchd from the camera does not, not to mention that the normal 25p footage always needs to be interpolated to progressive otherwise it will look like poo...

I also tested 50i with twixtor to around 120fps, works great with shallow depth of field and closeup, and just the 180 degree (=100) Did also test it with higher shutter speeds, but to my surprise the 180 degree worked better with twixtor.

Have to say, that this slomo trick on the C100 gives wayyy beter and usable results then the canon DSLR's like the 7d's of this world.

Cheers
 
You must log in or register to reply here.
Back
Top