OK…as if HD wasn’t confusing enough with all these formats: HDV, DVCPRO HD, AVCHD, AVCIntra, HDCAM, XDCAM, XDCAM EX, HDCAM SR, D5…did I forget anything? Then there are all of the frame sizes and frame rates…23.98, 24, 25, 29.97, 50, 59.94, 60…mind spinning yet? Mine is.
Especially when trying to figure out why “they” (whoever the HELL “they” are) did this:
720p at 59.94 is 60 ACTUAL frames per second. 60 individual frames per second that run at a 59.94 frequency/frame rate. In the DVCPRO HD world at least, not sure what JVC does with it’s 720p HDV camera. But then we have 1080i 59.94. Now THIS format isn’t 60fps…but 30 actual frames per second. 60 interlaced FIELDS…and this runs at 29.97fps. So since this format runs at 29.97fps…why the hell do they call it 59.94?
This causes so much confusion with people that it is no longer funny. Well, it never was. I tried until I was blue in the face to explain to a post supervisor that 1080i59.94 DVCPRO HD ran at 30fps. He didn’t buy it. I even showed him the time code numbers, and he still was skeptical. But this was captured on an Avid at 15:1 so he thought that certain frames weren’t captured since 15:1 was a 30 frame format. I finally had to show him on the deck.
SO when I work with people and try to talk about 720p 59.94 and 1080i 59.94 when we are talking about shooting options, there is a lot of confusion. They want to shoot 60fps for slow motion, and I say “you can only do that at 720p 59.94 because that is 60fps…1080i 59.94 isn’t 60 fps.”
I always get the reply “why not? 1080i 59.94…that is the same number as 720p 59.94…they are both 59.94, so why can’t I shoot 60fps at 1080i?”
“Because ‘i’ stands for interlaced meaning 60 interlaced fields, and ‘p’ means progressive meaning 60 full frames. Notice there isn’t a 1080p60 setting?”
Needless to say this takes a LOT of time to explain to producers/post supervisors. So, can anyone shed light as to why they call 1080i 59.94 that, and not 1080i 29.97? That would save a LOT of confusion. HD is confusing enough.