HMC 150, native progressive recording in 24p only?

S

Soundfx4

Active member
I'm planning on renting this camera soon and 1080/30 p would probably be best for what I'm recording, but I'm worried about interlaced footage. The instruction manual for this book mentions that in PH mode, 1080/30p is over 60i, but 1080/24p is Native.

I just would like to know if I record in 1080/30p and then open my videos up on a computer, am I going to be greeted by those horrible interlaced lines that haunt me in my nightmares?

Thanks much ^.^
 
Barry_Green said:
No, you will not see any interlaced lines. Just be sure to edit using a 30p timeline.
Click to expand...

Is over 60i just a compatibility thing, but it still stores whole frames? And is there some sort of 2:3 pull down involved? I suppose all I really need to know for sure is that it won't be interlaced, but I can't help but question everything, I'm quite the curious type :2vrolijk_08:

Thanks! :)
 
Denwa said:
There is no pull down. On 30P timeline it reconstructs the 30P from the 60i.
Click to expand...

interesting, is there a wiki article link that you know of that I could read over? I'm familiar with turning 24p into 60i (somewhat, it's still cloudy but meh) but I'm not so sure of 30p from 60i. I'd assume it'd be more strait forward? Is it flat out as simple as splitting each frame into two fields to get 60i, and then just putting them back together to get 30p?
 
technically, there's no difference between 30p and 60i footage once it's captured.... the difference is really in HOW it's captured. The both contain the same amount of data (so no pulldown), and are generally DISPLAYED the same way.

There's no real standard for 30p that i know of (most likely because of this lack of real difference)... standards in the US are 720/60p, 1080/60i, and 1080/60p on a few devices. Many devices recognize 24p and handle it specially, and there are some standards for it in terms of how it's stored on a disc. But its usually converted into one of the standard streams on the way to the display.

Now you MAY need to handle 30p footage specially in your NLE. FCP, for example, doesn't have a concept of 480/30p on ingest; it ingests 480/60i. For most purposes, you won't see a difference. But if you end up SCALING the footage, you have to force FCP to acknowledge that it's progressive (by setting the clip's property of "field dominance" to "none". Otherwise, you can lose resolution as FCP tries to compensate for nonexistent interlacing as it scales.

So, I'm not familiar with this issue in other NLEs, but at least with FCP, you want to make sure that you set the correct field dominance if:
1) You're editing a progressive format that ingests as 60i; and
2) You're scaling the footage somewhere along the way

I also often "trick" the HMC into recording 30p in HA mode (by setting the shutter to 1/30). This of course is not recognized by either the camera or by FCP as progressive footage... but if I need to scale it, again, setting the field dominance to "none" is necessary and sufficient!

Cheers,
Barry
 
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