View Full Version : GH1 Slo-mo


Dana Salsbury
December 12th, 2009, 10:43 AM
I'm looking into getting a GH1 and am wondering how the slo-mo works. Do you set it into a slo-mo mode and not have to do anything in post or does it just change the shutter speed?

Paulo Teixeira
December 12th, 2009, 11:04 AM
You first shoot in 720 60p and it plays back at normal speed. Make sure you have something like a 29.97 or 23.98 timeline and have the editor interpret the footage as those frame rates. That's how Premiere is.

Dana Salsbury
December 12th, 2009, 11:56 AM
Thanks Paulo. I didn't know if DSLRs did some funky stuff with that or not.

Paulo Teixeira
December 12th, 2009, 12:18 PM
You would have to have something that can over crank like an HPX170 and EX1R for example, if you wanted to have slow motion with-in the camera. Their are consumer camcorders that has slow motion but the resolution is less than SD.

Carlo Zanella
December 14th, 2009, 02:13 PM
I'm looking into getting a GH1 and am wondering how the slo-mo works. Do you set it into a slo-mo mode and not have to do anything in post or does it just change the shutter speed?

Shoot ad 720 60p. If you use Vegas, just import the clip and under the properties set the clip's speed at 0.500. It will palyback your clip in 50% slowmo, very nicely!

Carlo Zanella
The Santa Fe TV Show (http://www.santafetvshow.com)

Peter Szilveszter
December 15th, 2009, 01:10 AM
Shoot ad 720 60p. If you use Vegas, just import the clip and under the properties set the clip's speed at 0.500. It will palyback your clip in 50% slowmo, very nicely!

Carlo Zanella
The Santa Fe TV Show (http://www.santafetvshow.com)

Also in Vegas set re-sampling to disabled (just above the clip speed) otherwise you get the ghosting when rendered out to progressive format.

Todd Norris
December 16th, 2009, 02:38 PM
For best results, set your shutter speed to 1/125th. If your shutter is any slower, you won't get the true benefit of shooting 60fps because the motion blur won't look correct. Any shutter speed below 1/60th in the GH1 actually drops the frame rate to 30fps and then the slo-mo effect doesn't work well at all.
So: shoot 720p60 at 1/125th shutter speed.

Josh Hayes
March 3rd, 2010, 08:20 PM
I shot at 720 60P and brought into FCP on a 23.98 timeline. Didn't play right. Still appeared to play at 60P. So I brought up the Change Speed window and reduced it to 50% speed to take a look. Looked allright, but not great by any means. About the same as my Sony V1U, so I'm guessing it didn't work properly.

Best results came from importing it into FCP, and keeping the sequence at 60 P (59.94) and then bringing up the Change Speed window, and reducing to 50%. Much smoother look that way.

Still not sure if that's the best way to go about it, but appears to be the best I've found so far.

John Wiley
March 3rd, 2010, 09:50 PM
You would have to have something that can over crank like an HPX170 and EX1R for example, if you wanted to have slow motion with-in the camera. Their are consumer camcorders that has slow motion but the resolution is less than SD.

Paulo, correct me if I'm wrong, but doesn't the GH1 at 60p record just as many frames as the EX1 or HPX170 at full overcrank? I know the 60p of the GH1 is not considered "overcranking" but once the footage is re-interpreted to 24p in an NLE won't it behave in exactly the same way?

Josh, If you are using FCP the best way to do it is to use cinema tools to interpret the footage as 24p. I can't remember exactly how as I haven't used FCP for about a year, but I remember it being very simple. Once you do that the footage should act like a slow motion 24p clip and it's properties should say it is 24p. If you do skip this step and want to drop a 60p clip straight onto a 24p timeline then you'll want to slow it down to 40% (24 divided by 60 = 0.4) for the smoothest slow motion results.

Barry Green
March 6th, 2010, 03:21 PM
You're not doing it right. Don't change the speed on the timeline. Instead, import the 60P footage into Cinema Tools and tell it to "conform" it to 23.98. Then drag the resulting file onto a 23.98 timeline, and you should see absolutely perfect slow mo.

Josh Hayes
March 16th, 2010, 10:40 AM
That does look smoother. Thanks for the advice. It looks good!

Matt Hoecker
March 17th, 2010, 06:44 PM
In Premiere I bring in the 60p footage (like mentioned above, if it's shot with a shutter priority of 1/125th the motion blur looks best) to a 24p timeline (23.976). Then I put it in the timeline, turn off frame blend and set the speed to 0.4 and voila. It looks wonderful. Only turn off frame blend if you're changing the speed to .4 in a 24p timeline or .5 in a 30p timeline though as this will perfectly sync each of the 60 frames up with the 24 or 30 in the timeline. Anything else and and you may get noticeable jumps in the video.

John Wiley
March 25th, 2010, 09:18 PM
It's even easier than that in Premiere... select all the files you'd like to conform from your project media list, right click and select "interpret footage." Then select the "Assume this frame rate" check box and type your project frame rate in the text box. I find this easier than doing it on the timeline because you can do it to all of your clips at once.

I'll be starting editing on a complex surf film soon and I'll have source material which is 50p, 60p, 24p, 50i, 25p and 60i. I'll edit in Premiere (normally I prefer vegas but there's a few things which make Premiere more suitable for this project. I'll bring all the footage into Premiere and then conform it all how I want it so that I can just drop clips straight on the timeline without having to worry about adjusting their frame rates to get the smoothest playback.