Hello. Many people in my school shoot on HD but then they talk about downgrading to SD while editing so they can't have their project done in HD. WHy is that?
I can see two possible reasons: one is to use a SD proxy to speed up the editing process, the other is the recognition that for most people, the delivery medium is a SD DVD.
Unlike HDV, DVCProHD uses intra-frame compression, which makes it much easier to edit than HDV. On a 3.2GHz P4D using Canopus Edius, I can edit three DVCProHD streams plus three DV25 streams in realtime. For me at least, downconverting to SD or creating a SD proxy is pointless, it would only increase storage requirements and complicate the workflow.
The processor I have is a P4D 840EE, a dual-core, hyperthreading-enabled model. If you have a basic hyperthreading 3.2GHz P4, then you are comparing apples and oranges.
But, Edius does have a well-deserved reputation for being extremely fast. The scenario above also included one 48KHz WAV file for audio, color correction to help match the DV and DVCProHD footage, and transitions.