1080pA vs. 720pN

[I, Filmmaker]

I've heard (when pulldown is removed in post) that 1080PA is less compressed than 720pn.....why is that?

[Barry_Green]

It is significantly less compressed. It's because 1080P mode has 2x the bandwidth (1080/24pA with pulldown removed is 80mbps, vs. 720/24pN which is 40mbps). There's about 20% more detail, but 100% more bandwidth, so it's a lot more mildly compressed.

Note, this is only really relevant for an HVX/HPX series camera. On an HPX3000/HPX3700, where it's capable of delivering the full 1920x1080 of detail, then 720p and 1080p would show comparable compression.

[I, Filmmaker]

SO, theoretically, 24pA with pulldown removed handles motion EXACTLY like 24pN?

[I, Filmmaker]

Since it was originally captured progressively, i mean.

[Barry_Green]

Not just "theoretically", but actually in reality yes. The exact same imaging process is occurring; the only thing that changes is the recording codec. But yes the motion is EXACTLY the same.

[I, Filmmaker]

Sorry for all these novice questions but, was DVCPROHD originated before there was alot of legitimate 1080p recording? I mean, for what reason does the camera split up it's 1080 progressive images into fields? Does this help the images fit into a smaller bitrate?

[TimurCivan]

it was invented before the 1080p24p mantra was started.....

[I, Filmmaker]

Than why does the HVX take an image that' already progressive, and then downgrade it like that. Into fields. Interlaced is so archaic and messy

[Barry_Green]

Because the 1080 codec is interlaced-only, and it's a SMPTE standard, and it's the broadcast standard.

Everyone would love a full 1080/60P but that just doesn't exist, not in recording or broadcast. There's no specifications for it, no standards for it. So it's either slow frame rate 1080p, or fast-refresh-rate 1080i. If you want progressive and fast refresh rate, that's what 720/60p is for.