Slow motion with the HM100

[Kajito Nagib]

I've done slow motion with my HM100 but it doesn't look too smooth it looks a little choppy.
Would the best record mode for slow motion would be 720-60P in a 30P or 24P timeline?
It's too bad there's no overcranking function with this camera maybe it can be done in a firmware update.

[Dennis Kane]

Look at Philip Bloom's review of the HM-100, he has an excellent example of slow motion.
Review of JVC GY HM 100 on Vimeo

[Kajito Nagib]

Hi Dennis I have but he didn't get into details that's why I posted the question. I did a test last night and rendered a clip in 30P and 24P in the timeline but didn't notice much of a difference.

[Kajito Nagib]

Here's what I did, I went into menu and selected 1280/60P(HQ) as my REC mode. In Vegas Pro 9 under properties I clicked on match media settings then I select the file which stores current info about the project. On the timeline I select the clip then slow the velocity. Now here's the part that's a little confusing to me do I render as 24P or 30P? I tried both but they both look the same to me.

[Jack Walker]

I don't have Vegas, but I think you may be setting your project up wrong.

What you want to do is setup up a project/timeline at 24p or 30p. Then drop the 60p video on this timeline. The 60p video will play at the framerate of your project and thus will automatically be in slow motion.

If you use a 30p timeline, the video will play at half speed. If you use a 24p the video will play at 2/5 speed (i.e. slowed 2-1/2 times).

The video should be shot at a shutter speed that correlates to the video shot at the frame rate of your timeline. Since 24p would be shot at 1/48, and 30p would be shot at 1/60, the 60p should be shot at 1/120 for the slo-mo stuff. However, since the JVC camera is hobbled to prevent this, 1/100 would the logical choice. For a nervous feel to the slo-mo, you might try shooting at 1/250 or higher.

Using the slo-motion tools inside editors will produce varying results, some not good, depending on how the video is being altered. For making alterations in speed that are different what you get by using the shoot and drop approach, look at the software plugin Twixtor... which is perhaps the best program for doing doing slow motion when the video has to be rewritten.

Instructions on exactly how to do the shoot and drop slow motion in Vegas might be quickly available on the Vegas forum.

[Kajito Nagib]

So let's say I shoot in 60P at 1/100 for the slow motion stuff and set the project timeline at 30P ok that part understood but do I need to render in 30P? Twixtor plugin isn't available for Vegas Pro 9:-(

[Jack Walker]

Originally Posted by Kajito Nagib

So let's say I shoot in 60P at 1/100 for the slow motion stuff and set the project timeline at 30P ok that part understood but do I need to render in 30P? Twixtor plugin isn't available for Vegas Pro 9:-(

The video does not have to be rendered. It just plays at 30p. Whether you have to change properties or something to tell Vegas you want it to be seen as (and play at) 30p, I don't know. Perhaps you can ask on the Vegas forum.

Rendering only needs to be done when the frames are altered. When you put 60p video on a 30p timeline, nothing is altered and nothing has to be rendered. It just plays frame by frame at a slower rate.

[Kajito Nagib]

Originally Posted by Jack Walker

The video does not have to be rendered. It just plays at 30p. Whether you have to change properties or something to tell Vegas you want it to be seen as (and play at) 30p, I don't know. Perhaps you can ask on the Vegas forum.

Rendering only needs to be done when the frames are altered. When you put 60p video on a 30p timeline, nothing is altered and nothing has to be rendered. It just plays frame by frame at a slower rate.

What I meant by rendering is converting a project into a multimedia file and formatting it for playback to be viewed on the internet (youtube Vimeo etc) What I don't understand is if I select my project at 30P or 24P then drop the 60P video on the timeline do I need to render it for 30P or 24P to match my project settings? For example if I select 24P drop 60P into the timeline do I need to render as HD EX 1280X720-24P or another format that ends with 24P or if using 30P drop 60P into the timeline do I need to render as 30P? I'm still a little confuse about this.

[James McBoyle]

Originally Posted by Kajito Nagib

What I meant by rendering is converting a project into a multimedia file and formatting it for playback to be viewed on the internet (youtube Vimeo etc) What I don't understand is if I select my project at 30P or 24P then drop the 60P video on the timeline do I need to render it for 30P or 24P to match my project settings? For example if I select 24P drop 60P into the timeline do I need to render as HD EX 1280X720-24P or another format that ends with 24P or if using 30P drop 60P into the timeline do I need to render as 30P? I'm still a little confuse about this.

If using a 60p source and you drop it into a 24p timeline then you would render it as 24p to get the effect you want. Same for 60p onto a 30p timeline, it would be rendered as a 30p film.

I use this myself fairly regularly when making football (soccer) highlights reels, there's nothing like a lovely smooth slo-mo shot of the ball hitting the back of the net :-)

Have Fun,
Jim.

[Kajito Nagib]

Originally Posted by James McBoyle

If using a 60p source and you drop it into a 24p timeline then you would render it as 24p to get the effect you want. Same for 60p onto a 30p timeline, it would be rendered as a 30p film.

I use this myself fairly regularly when making football (soccer) highlights reels, there's nothing like a lovely smooth slo-mo shot of the ball hitting the back of the net :-)

Have Fun,
Jim.

ok that's what I thought project settings should match rendering for smooth slow-mo.
Which frame size or frame rate would be better for slo-mo 1080-60i, 720-60P or 720-24?

[Jack Walker]

Originally Posted by Kajito Nagib

ok that's what I thought project settings should match rendering for smooth slow-mo.
Which frame size or frame rate would be better for slo-mo 1080-60i, 720-60P or 720-24?

Shoot at 720p60.
Drop the video on a 720p24 or 720p30 timeline.
That's it!

Export using whatever size and codec you need for your use.

[Kajito Nagib]

Originally Posted by Jack Walker

Shoot at 720p60.
Drop the video on a 720p24 or 720p30 timeline.
That's it!

Export using whatever size and codec you need for your use.

ok got it! thanks everyone.

[Kajito Nagib]

Originally Posted by Jack Walker

24p would be shot at 1/48,

Jack HM100 also prevents 1/48 so in 24P should I shoot 1/60 or 1/30?

[Jack Walker]

Originally Posted by Kajito Nagib

Jack HM100 also prevents 1/48 so in 24P should I shoot 1/60 or 1/30?

You can shoot 24p at 1/48 with the HM100.

What's missing is 1/120 with 60p and 1/100 with 50p. Why JVC has hobbled the camera this way, I don't know. However, to be fair, the HD110 I have is also hobbled this way, so it is a JVC tradition. (Yes, I know the HD110 can't shoot 60p HD... but it can shoot 60p SD, and in this mode 1/120 is blocked/not available.)

If there were a legitimate reason for hobbling these shutter speeds, I am confident JVC would be the first to explain the rationale. However, since JVC is no where to be found on these issues, I can only suppose the worst of intentions as far as the customer is concerned.

Back to the issue. For the "normal" look, shoot at 1/48 with 24p and 1/60 with 30p. For 60p 1/100 will probably give the best results, but if you are shooting fast action, 1/250--the next available shutter speed on the HM100--might give better results.

In any case, doing some tests of the various shutter speeds on the type of subjects you are shooting will show you exactly how each of the shutter speeds look, helping you to make the best choice.

[Kajito Nagib]

Originally Posted by Jack Walker

You can shoot 24p at 1/48 with the HM100.

What's missing is 1/120 with 60p and 1/100 with 50p. Why JVC has hobbled the camera this way, I don't know. However, to be fair, the HD110 I have is also hobbled this way, so it is a JVC tradition. (Yes, I know the HD110 can't shoot 60p HD... but it can shoot 60p SD, and in this mode 1/120 is blocked/not available.)

If there were a legitimate reason for hobbling these shutter speeds, I am confident JVC would be the first to explain the rationale. However, since JVC is no where to be found on these issues, I can only suppose the worst of intentions as far as the customer is concerned.

Back to the issue. For the "normal" look, shoot at 1/48 with 24p and 1/60 with 30p. For 60p 1/100 will probably give the best results, but if you are shooting fast action, 1/250--the next available shutter speed on the HM100--might give better results.

In any case, doing some tests of the various shutter speeds on the type of subjects you are shooting will show you exactly how each of the shutter speeds look, helping you to make the best choice.

your right to see 1/48 you need to be in 24P mode I was in 720-60P so it didn't come up
my mistake. I will run some test this weekend to see which of the two will play back a smoother slow-mo 24P or 30P.
thanks again for your help.