Lightweight? Compared to what?

So what's the deal? Isn't ProRes 422 supposed to be a lightweight codec? Well, compared to uncompressed HD, yeah. But keep that "data rates comparable to uncompressed SD" thing in mind. You've already been using HD formats that are smaller than uncompressed SD, and pretty much all of those are smaller than ProRes 145. Even HDCAM is only 140 Mbps!

So ask yourself, is your system capable of capturing 10-bit uncompressed SD? Good. But because the footage is uncompressed, it doesn't engage your computer's processor. It's mostly just a pipe and drive question. ProRes still has those, but raises the degree of difficulty by also throwing in some processing for the on-the-fly encode.

As JeremyG notes: Indeed The ProRes codec is a major advancement, but it takes a lot of horsepower to compress/decompress. That's why something like the ioHD (with the codec built in to compress/decompress) will help 'older' systems.

 This too pops up several times. Hardware is good, especially when it has hardwired codecs.

Although Jeremy was posting in one of the AJA forums, and AJA made their big announcement in April, Blackmagic Designs announced in May that they too support ProRes 422 capture, playback, output -- the whole magilla.

Now, among the benefits of a light weight (alright, a lighter weight) codec is the smaller storage footprint and bandwidth. But again, compared to what? Let's start with HDCAM's data rate, which is 140 Mbps. Less than ProRes's 145 Mbps. DVCPRO HD? 100 Mbps. HDV is 25 of course--but that's for part 2.

But you get the idea. Less than uncompressed, yes. But ProRes 220 is twice as heavy as DVCPRO HD. Still benefits galore, especially when using workflow's as clever as this one recommended by Walter B.: of course, you can easily capture DVCPro HD, create a ProRes timeline and then work like that. Then you render before output, but using the Pro Res codec.

Having said all that, don't forget that 145 Mbps is plenty enough to strain even very recent non-Intel Macs.. It's a strain on many drives, including some arrays, especially as you get to the 220 data rate.

So even at 145, it's really not the lightest weight of HD formats, not by a long shot.

Ah, but here's where it starts to get fun.