View Full Version : Shutter Speed and More


Chris C. Collins
April 7th, 2007, 11:14 AM
What are the advantages of shooting at high shutter speeds?

Also, I know to shoot 1/48 while in 24p but what about in 60i?
Is it the same ratio? Is 1/120 the correct speed to shoot in 60i?

Finally, what shutter speed or configuration would give you the best/smoothest slow motion. I've been to the Slow Motion thread but it focuses more on POST-Producing the best slow-mo. I'm thinking like Clockwork Orange water scene slow motion or Full Metal Jacket snipes in slow motion. As smooooth as possible.

Thanks in advance.
-C. Collins

Greg Boston
April 7th, 2007, 12:09 PM
Chris,

See this thread. It's essentially the same thing you are asking.

http://www.dvinfo.net/conf/showthread.php?t=90923

regards,

-gb-

Chris C. Collins
April 8th, 2007, 08:12 AM
I was just in that thread, it's actually what sparked my question, and none of my questions are answered there.

Kevin Randolph
April 10th, 2007, 02:52 PM
when shooting 60i use 1/60 shutter. This should yield results that you will be happy with. As a general rule you don't want to adjust for exposure using the shutter speed. Only adjust the shutter speed for creative reasons - to get a certain "look."

Basically, when shooting in any "p" (progressive) mode, your shutter speed is going to be double your frame rate. 24p gets a 1/48 shutter. 30p gets a 1/60 shutter. If you are shooting in an "i" (interlaced) mode, your shutter speed should be the same as your frame rate. 60i gets a 1/60 shutter.

Now, these are starting points. You can do anything you want for creative effects or to achieve a particular feel. But these will give you a good jumping off point.

Ash Greyson
April 10th, 2007, 09:03 PM
For slow-mo, 60i is always best... at least with the XL2.



ash =o)

Adam Bray
April 11th, 2007, 08:14 AM
For slow-mo, 60i is always best... at least with the XL2.

ash =o)


Bump up the shutter to 1/120 for that situation too?

Jonathan Kirsch
April 11th, 2007, 01:24 PM
As a general rule you don't want to adjust for exposure using the shutter speed. Only adjust the shutter speed for creative reasons - to get a certain "look."

Basically, when shooting in any "p" (progressive) mode, your shutter speed is going to be double your frame rate. 24p gets a 1/48 shutter. 30p gets a 1/60 shutter. If you are shooting in an "i" (interlaced) mode, your shutter speed should be the same as your frame rate. 60i gets a 1/60 shutter.

I agree with the starting points statement, but I don't agree that it's for creative purposes only. There's times when you're shooting 30p for example and your iris is already wide open, you have to go down to 1/30 to let more light in. I'd say that's a case where it's not a creative purpose, it's a necessity purpose. Sorry to nitpick.

Jonathan

Chris C. Collins
April 11th, 2007, 04:19 PM
I agree with the starting points statement, but I don't agree that it's for creative purposes only. There's times when you're shooting 30p for example and your iris is already wide open, you have to go down to 1/30 to let more light in. I'd say that's a case where it's not a creative purpose, it's a necessity purpose. Sorry to nitpick.

JonathanAs a last resort, I would agree with adjusting the shutter for light. But only if you had no other way of getting the light.

Thanks for the input, but I still have one unanswered question: What about shutter speed related to post slow-mo? Wouldn't a higher shutter improve smoothness in slow motion?

Jonathan Kirsch
April 11th, 2007, 04:34 PM
Yeah, I guess I chose the wrong words. I couldn't think of "last resort" for some reason (long work day already)...that sums it up pretty good. No offense meant towards Kevin.

Jonathan

Ash Greyson
April 11th, 2007, 05:03 PM
Bump up the shutter to 1/120 for that situation too?


Nope, it should be 1/60th




ash =o)

Chris C. Collins
April 11th, 2007, 06:11 PM
Nope, it should be 1/60th




ash =o)Hey Ash, could ya answer MY question please? ;)

Kevin Randolph
April 11th, 2007, 06:24 PM
Chris, a higher shutter speed will help eliminate motion blur and give you a better slow motion effect when the footage is slowed down in your NLE. I don't have any recommendations for an appropriate shutter speed though. It's been quite a while since I've had a reason to do slow motion... Check around here though, there are several threads talking about it and they also mention things like shooting in 60i and splitting the fields into two frames to get 60p witch automatically slows your motion down by half. Good luck on your foray...

Hope this helps...

Kevin

Richard Hunter
April 11th, 2007, 06:34 PM
Thanks for the input, but I still have one unanswered question: What about shutter speed related to post slow-mo? Wouldn't a higher shutter improve smoothness in slow motion?

Faster shutter will improve the sharpness of the image during slow-mo, but is also likely to cause more juddering because there is less motion blur. The actual effect depends on how fast the object is moving to begin with.

Richard.

Ash Greyson
April 11th, 2007, 06:53 PM
Answer...it depends on what software you are using. Most people use After Effects which seems to work best with 60i footage at 1/60th that it can convert to 60P, giving you 40% of real time motion



ash =o)

Chris C. Collins
April 11th, 2007, 09:15 PM
I am using, or would prefer to use Sony Vegas.
I have After Effects though, although I try to avoid it if possible since my computer really doesn't like it. It lags hardcore and takes way too long.

Greg Boston
April 11th, 2007, 09:57 PM
The other part of the question that you need to ask yourself for doing slo-mo is what will it be used for? I say this because I will typically use a higher shutter speed so that I absolutely freeze motion in each frame. That's because I want to be able to do motion analysis and I need a crisp picture to look at when I pause playback.

For other slo-mo work, you might want to retain some motion blur by using a slower shutter which will look smoother when played back at 1X.

-gb-