My friend shoots outdoors/nature videos and he just got the Sony X70 camera (upgrade from old VX-2000 DV camera) and I helped him get oriented on it yesterday.

My first thought was that he could shoot in 1080p60, since he could edit as 30p and get nice slow-mo that way. However, some of his footage may end up being sold for use on outdoors TV shows and I'm being told they might prefer 1080i source clips for broadcast.

So the question is - how does 1080p60 convert to 1080i? Does it look identical to footage shot as 60i? My thought is that 60p has 60 frames, while 60i has 60 fields. Therefore, I'd think that the conversion software (Adobe Media Encoder) could simply take those full fields from 60p and use half of each one to create the 60 fields for 1080i. In my head that makes perfect sense and should work in theory.

Is it that simple? I understand temporal resolution and such. Anyone doing this that can comment on results? I don't have any footage right now to experiment with myself or I would just try it, no access to camera.

Thank you

Jeff

Going from 60i to 60p can be tough. 60p to 60i, on the other hand, is easy.

The quality can depend on the encoder though. If there are flicker problems, do some vertical filtering before the 60i render.

One tip is to edit on 29.97 fps boundaries, which aligns with SMPTE time code. If you make a cut on 59.94 fps boundaries, you might split a field between one picture and another. And when that mixed 60i frame gets converted to 720p60, you'll end up with progressive frames at the boundary where various lines are of different pictures!

60i and 60P have the same temporal motion so really look the same. Certainly on a modern interpolating TV like my Sony 240Hz, they look identical. I shoot 60i on my NX5U ( it can't shoot 60P in 1080 ) and 60P on my NX30U, CX700, FDR-AX1 and FDR-AX100. I edit on a 60i timeline in EDIUS and it all works. If I want some nice stills I can get them from one of the cameras shooting 60P. If I had a choice I would shoot everything at 60P since it is then possible to edit on a 60i timeline for DVD or Bluray and if you want the slow frame rate look it will also edit on a 30P timeline ( just skips frames ) or slow motion depending on your software and how you set it up to edit.

Ron Evans

It's that simple. How Do I know? I was concerned about this a while ago and rather than take anyone's word I tested it for myself by using animation software to make a 60 frame sequence with each frame numbered consecutively from 1 to 60. Rendered at 30p, only the odd numbered frames appeared. At 60i, there was a number in each field. I use Vegas, but I don't think Edius is different in this regard. If you have concerns you could do the same experiment.

I have EDIUS and Vegas and they work the same way as described. Shoot 60P ( 59.94 ) as it gives the wide choice in editing and output.

Ron Evans

Thanks all! Doing this to help a friend that has been shooting miniDV forever, and my own cameras are 1080i only, so my testing options are limited until I can get more time with his new X70. He's counting on me for tech assistance/guidance.

Thanks again

Jeff

Any updates? Any more shooting / testing on the X70?

Hi Phil,

I've been able to use the camera on a few of my own jobs, but stuck with 1080i to fit my existing workflow. The camera owner is shooting 60p, and while he has shot a bunch of new material, he hasn't done much, if any editing of it yet (summer is fishing guide season and he is out every single day). Plus he doesn't live real close to me. If I get over there and have a chance to work with him on editing, will report the results

Thanks

Jeff

I tried an X70 for a day and still have the 60P files I took then. They work fine in a 60P or 60i project with files from the rest of my cameras. NX5U, FDR-AX100, AX53, FDR-AX1, NX30U. I use EDIUS and these files work fine in either a 60i or 60P project. So a mix of AVCHD from the NX5U and NX30U, XAVC-S from the others and of course XAVC-L from the X70. That was a year ago as I bought the AX100 instead of the X70.

Ron Evans