Jump to content

No slow motion with high frame rate video footage?


Patrick Cooper

Recommended Posts

As many will know, the PAL version of the Panasonic G6 has an option to record at 50fps. I wanted to use this setting to shoot some slow motion footage. My only previous experience with filming at high frame rates is with movie film (super 8 in particular.) I had a Canon 1014 Autozoom Electronic super 8 camera which had a top speed of 54fps. The principle for producing slow motion footage with this dinosaur technology was pretty simple – film at 54fps and then project the developed film at 18 or 25fps. The results were great by the way – beautifully smooth slow motion.

 

Now back to this Panasonic G6 footage – when I placed the footage on the timeline in Sony Movie Studio, I set the video properties to 1920 x 1080, 50i (25fps.) And also exported the clip at 50i (25fps.) The result? Motion looks completely normal. There is no slow motion. I'm seriously puzzled.

Link to comment
Share on other sites

  • Premium Member

I think you answered your own question earlier. 50i isn't a frame rate, it's just 25 with two fields per frame. So when you set playback to 25fps, you're basically playing it normally. To get slow-mo out of a field based capture system, you need to apply the "slow-mo" filter on your editing program and it will deliver you a much nicer/cleaner slow-mo then if you shot at 25fps.

Link to comment
Share on other sites

Are you stretching the clip out itself in the timeline?

 

That is certainly a possibility. Though I thought that was done to footage that was shot at normal frame rates (eg 25fps) to slow it down. And of course, the results don't look as smooth as footage that was shot at a higher frame rate. For footage that was shot at higher fps, I thought there would be some automatic command that you could initialise in the software that would display it as 25fps (without dumping frames.) Someone on another forum is suggesting that my software is discarding every second frame so that it plays back at the same duration that it was recorded at. So for example, a 5 second clip (recorded in camera) will remain a 5 second clip on the timeline. Whereas I was expecting the duration of the clip to double (a 5 second clip becoming a 10 second clip. etc)

Link to comment
Share on other sites

Did you actually shoot at 50P instead of 50i? If so, the editing software is converting 50P to 50i rather than playing it at 25P -- there must be a setting that will stop it from just straight converting 50 frames into 50 fields.

 

That's right. The footage was shot at 50p. Here's what the camera's menu says:

 

AVCHD Progressive, 1920 x 1080, 50p, Image Sensor Output 50p, 28Mbps.

 

I think Ive given up the idea of converting it to interlaced (that just complicates things.) On my last attempt, I converted it to 1280 x 720, 25p but I'm still ending up with normal looking footage (no slow motion.) Though when I first import the footage into Sony Movie Studio, the software is indicating that it's 25fps footage. But that can't be. I am definite that I was recording at 50p.

Link to comment
Share on other sites

When playing back the footage on the camera's lcd screen, the footage looks normal / no slow mo. Though I'm guessing not everyone who chooses the 50p setting necessarily wants slow motion footage. There is a youtube video shot by someone who has the NTSC version of the G6 and he played a clip that he shot at 60p. He was able to produce really nice smooth slow motion footage from that with his software (not really sure which software he uses.)

 

Thanks for the link! I'll check it out.

Link to comment
Share on other sites

I tried the first option in that link (the video event properties box) but something very odd is happening. For the playback rate (inside that box), I'm putting in 0.5 but as soon as I place my cursor in another field within the box, another two 0s are added to the end of the 5, making it 0.500. I then scrolled down using the down arrow and saw the numbers descending. It looked it was going to take a long time to get to 0.5 (going through all the hundreds.) But it didn't even get close. It stopped when I reached 0.250 and refuses to go any further. Looking at the sample of the video event properties box in the link you provided, I note that it says 59.940fps near the bottom right hand corner. I'm assuming that this is the frame rate that the footage was originally shot at. When I look at the same area in the box (with regards to my own footage), it says 25.000fps. So I'm guessing that for some reason, Sony Movie Studio thinks that my footage was shot at 25fps and is treating it like such. Though I'm certain that it was shot at 50p.

 

I guess I could try stretching out the footage on the timeline and seeing how it looks. But I don't have high hopes.

Edited by Patrick Cooper
Link to comment
Share on other sites

  • Premium Member

I still think the camera doesn't shoot 50 progressive frames per second. I think it shoots 60i and extrapolates different formats based on how the file is flagged. That's how a lot of MPEG cameras work.

 

You have to figure out how to un-flag the file. Unfortunately, most of the basic software only identifies thinks like frame rates based on the flags.

 

If you want to post a file on dropbox, I will gladly fix it for you. :)

Link to comment
Share on other sites

I still think the camera doesn't shoot 50 progressive frames per second. I think it shoots 60i and extrapolates different formats based on how the file is flagged. That's how a lot of MPEG cameras work.

 

You have to figure out how to un-flag the file. Unfortunately, most of the basic software only identifies thinks like frame rates based on the flags.

 

If you want to post a file on dropbox, I will gladly fix it for you. :)

 

The G6 has a number of video recording options. Two of these are very similar but not quite the same

 

The option at the top of the menu is as follows:

 

AVCHD Progressive - 1920 x 1080 50p - Image Sensor Output 50p, 28Mbps

 

The second option in the menu is as follows:

 

AVCHD - 1920 X 1080 50i - Image Sensor Output 50p, 17Mbps.

 

Ive tried Dropbox in the past but couldn't get it work. I was trying to share a video but it kept returning an error. I might have to look at using Google Drive instead.

Link to comment
Share on other sites

Does Sony Movie Studio allow you to directly import higher frame footage so that you can have slow motion? I know that Lightworks currently doesn't allow this, perhaps in that case a left over from the days of being mostly used on film productions, where the higher frame rates were created before the telecine, Although you can change the speed in the timeline, it's not the same as having been originally shot at a high frame rate.

Link to comment
Share on other sites

Does Sony Movie Studio allow you to directly import higher frame footage so that you can have slow motion? I know that Lightworks currently doesn't allow this, perhaps in that case a left over from the days of being mostly used on film productions, where the higher frame rates were created before the telecine, Although you can change the speed in the timeline, it's not the same as having been originally shot at a high frame rate.

 

I wish it was that simple. In Movie Studio, I went to New Project but with regards to frame rates (next to HDV and AVCHD) I just saw regular options like 24p.25p, 50i. Though I'm not 100% sure whether those are the frame rates that the footage will be imported as or whether those are the frame rates that it will be converted to on the timeline (once imported.)

Edited by Patrick Cooper
Link to comment
Share on other sites

I think given that even the camera plays these files at normal speed.. you have just recorded at 50 fps.. rather than 50 fps within a 25fps setting.. my camera can do this too.. but you have to select the 50 fps.. within a 25fps setting that is your main frame rate.. to have slo mo.. I think the problem is your settings in the camera itself..

Link to comment
Share on other sites

you have to select the 50 fps.. within a 25fps setting that is your main frame rate.. to have slo mo.. I think the problem is your settings in the camera itself..

 

I don't think that option exists on my camera. I'm basically limited to the menu options. For example - record at 50p and output as 50p, or record as 50i and output as 50p etc. Or alternatively record at 50i and output as 25p. I guess if there was an option that would allow the camera to record at 50p and output as 25p, that would give a slow motion effect when playing back the footage on the camera. But I cannot see such an option.

Edited by Patrick Cooper
Link to comment
Share on other sites

Ok sorry.. just an idea.. thats how my camera achieves slo mo.. you set to eg 50 but within a 25p main frame rate setting.. you can choose 50p in another setting, just to shoot 50p for "normal" motion..

 

I wish my G6 had that option. Sounds like it would make life much more simple.

Link to comment
Share on other sites

According to someone on another forum, 0.5 is the same as 0.500. So I did this option (with the video properties box.) The resulting slow motion doesn't look as smooth as I was expecting. Looks more like regular footage that's been slowed down. Although I admit - the footage was hand held with a telephoto lens so that might have something to do with it.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...