Shoot in-camera 720p (60fps) or 1080p (30fps) and slow down in post? I am excited about the SDHC media solutions that have been developed by some of you in the community here. Thank you so much! Planning a month and a half in the Canadian arctic in 2009, and this means maybe not even having to bring a laptop into the wilderness and worrying about power for it. Back to my question: the SDHC solution doesn't allow for overcranking it seems, but if one is seeking BEST IMAGE QUALITY with the EX1, wouldn't that be achieved using the highest quality footage first (1080p) and then slowing down in post? I'm using FCP , Motion (optical flow for slow- mo). Besides, it's often difficult to know until you are editing just what pieces you might want slowed down, and to what rate. EX1 doesn't do 60fps in 1080P (unlike the shoulder mount XD Cams), so you would be throwing out detail from the get go. My goal is to maintain highest image quality to satisfy HD broadcasters. Should I ever bother overcranking in camera if the quality will suffer, or am I missing something? Thanks...

720p is part of the official HD broadcast standard. Why on earth would it not be supported? Many cameras cannot overcrank at their best resolution. I don't see this as an issue. The 720p image out of the EX1 is lovely, and certainly nothing anyone would fault you for. It's also more pleasant to work with in post.

If you need the overcranking, shoot 720p60 or do real overcranking. Yes, the SDHC solution will not work for overcranking but they DO work for 720p60. So if that works for you, you're golden.

I even think that 720p does a better downconvert to SD Mpeg. I'm testing 1080p vs 720p and have found 720p gives a better image, why I dont know. What i'm thinking is that there is less info to downconvert to SD.
Sorry re read your post and your going to broadcasters. 720p is still fine though

Thanks... but I'm still wondering if anyone has done a comparison as to which method yields the highest image quality. As a side note, editing on a 1080P 37" Sharp Aquos LCD, I do find the 1080P footage I shoot to be more nicer than the 720P, though it is also very nice, more pixels is more pixels :)

No question it's 720/60P, otherwise "Planet Earth" would have been shot on Sony F900 at 1080/30P rather than 720P Varicams. You just can't get the smooth slomo in post production from 30P material. It's better from 60i by de-interlacing but still a bit jittery and of course you're losing resolution in the process so losing the benefit of 1080.
Steve

Thanks for the Planet Earth example... that kind of clear example in the broadcast world helps a great deal.

Certainly use 720/60, we recently did a shoot with a HDCam 790 shooting as "A" camera and an EX1 shooting slowmo at 720/60 at the same time. If I slowmo the 790 footage it doesn't look anywhere near as good as the EX1.

I'd post an example but some of you may be offended by footage of a female dancer in her underwear!

What about 720/50 for pal?

Steve, might I ask how you are doing slowmo? Are you using the NLE or something like Twixtor or Motion (with optical reflow on).

SlowMo in Motion with optical flow on.

720/50 for PAl would be the same as 720/60 for NTSC.
But if you're after slomo for PAL, you might as well use 720/60, or is there a reason not to that I don't know about?
Steve

I'd post an example but some of you may be offended by footage of a female dancer in her underwear![/Q

oh no, by all means let us see. we're all professional adults here. post away!!!

http://www.flyingmachinestv.co.uk/framerate.wmv 68mb file.

It's not very scientific but it may help.

(WARNING: If you are offended by women in skimpy underwear then don't download)

It was hard to judge well because of the difference in framing, but the EX1 certainly looked smoother in slow mo.

As an aside, how was this lit? Looked quite good actually.

If one doesn't have the overcranking limitation by the SDHC cards, isn't it better to do 720p (30fps) overcranked to 60fps in camera, than to do 720p (60fps) and slow in post? I just want to make sure I'm understanding this correctly and the solutions you're giving are specific to the SDHC limitations.

Yes, that's the easiest way to do it - you mean with the SQ Motion function in the menus yes? In this way you can also view it at slomo speed straight off in-camera, something you couldn't even do with the old Varicams!
Steve

It was hard to judge well because of the difference in framing, but the EX1 certainly looked smoother in slow mo.

Okay, here's another 'all about slomo' movie, not EX1, but useful for Compressor users:

http://www.vimeo.com/779651

No skimpy women with underwear, but would agree with previous posts that EX1 clip looked smoother, and that generating frames - no matter how beautifully - doesn't compete with capturing more frames per second from the get go.

It was hard to judge well because of the difference in framing, but the EX1 certainly looked smoother in slow mo.

As an aside, how was this lit? Looked quite good actually.

Lit by very experienced DOP (not me!) just 3 lights. There's some much more spectacular footage from that shoot but I'm not allowed to post it!

Overcrank in camera runs at much higher data rate so when played back at your target speed, you get real (not synthesized) frames at 35mbps VBR. In fact that high data rate is why SDHC and Sony hard drive can't do overcrank to max frame rate (apparently due Sony's built in USB limit though). I think real frames are better than synthesized frames otherwise Phantom cameras would rent for so much.

Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)?
Steve

Yes actually correct and verified.
720p24/60 uses about 2.5x the data rate that 720p60 uses.
The XDCAM spec is 35mbps VBR playback. In order to achieve that playback rate a lot more data must be recorded per second. It's also one reason why DPs prefer shooting with high speed video over synthesized frames.

720p60 (NOT overcranked) is exactly the same data rate as 1080p30.

BTW on a tangent 720p24 (23.98) does have more data per pixel that 1080p30. The data rate is per second so at smaller frame size and fewer frames per second, you get more bits to describe a give "pixel."

Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)?
Steve

Is that actually correct Craig, surely at 720/60P you've got the same amount of data as 1080/30P (ie twice the rate but half the pixels)?
Steve

720/60P is not overcrank in the sense of slow-quick motion. It's still a 35mbps VBR which is why SDHC can do it. Overcranking to 60p in slow and quick motion is different.

Sorry Craig, misunderstood what you were saying, I have heard that the SQ Motion uses higher rate than 720/60P.
Steve

I think what you were asking is:

Optical Flow Slo Mo (like in Apple Motion) at 1080P vs in Camera at 720P

I've done a bit of this on the EX1 with 1080P 30P. If the original image quality is good, and there isn't too much motion blur in the footage, you can get pretty good slo mo up to 1/2 speed. The resultant images are 1080P, which is quite a bit higher res than 720.

I haven't tried 720P 60P normal acquisition and changing that to slo mo in post by putting that video into a slower framerate timeline. I guess is you shot everything at 720P then you could decide on a 24P or 30P timeline and then decide what footage you wanted slow mo. Seems there might be workflow issue for the non-slowed footage, such as sound. Not sure about that.

I don't usually shoot 1080P with the intention of slowing it down. The optical flow process takes a really long time, and I have one of the fastest systems you can get right now and internal RAID 0, and it still takes a long time for just a few seconds. It also takes an immense amount of hard drive space for the optical flow software to create it's interpolation data. I usually will use the optical flow when I realize I need a pan to take longer, or I something I found would work better in slomo that I didn't plan for in the field. It's just not all that convenient.

When I plan for slomo, I do it with 720P S&Q settings in the EX1.

The thing about optical flow is that ideally you want the shutter to be fast, like 1/250 of a second of faster, so there is very little motion blur so that the optical flow has better edges to work with and can interpolate the in-between frames more accurately. If there is a lot of non-linear movement between frames, which there might be at 1080 30P, optical flow will not know what to do and will make some whacky guesses. An example is a dog fight that I happened to capture when I was at a dog park. When I looked at it later, the action was so fast that I needed to slow it down. I tried to use Motion's optical flow to slow it down. It interpolated and morphed the dog's limbs and movement into strange, unnatural swirly things. This was because of the distance between frames (I was shooting 30P), the texture of the dog fur, and the motion blur because I was using normal shutter speeds.

So, if you can plan, and you want to do all this in post, you can shoot 1080P, make sure the shutter speed is fast, that the motion of what you're capturing isn't too complex, and indeed you will have a higher-res slomo after spending a lot of post processing time on it. Theoretically it might be sharper.

Or you could shoot 720P slo-mo with S&Q and get pretty high-bitrate slomo. You could uprez (using optical flow) and sharpen in post and get an image similar to 1080P but with more natural motion.

I hope this helps.

I did a few EX1 slow motion tests at various settings, with some side-by-side comparisons. 720p with S&Q at 60 is by far the best and smoothest.

Sony EX1 Slow Motion Test on Vimeo (http://www.vimeo.com/6432682)

shooting 720p24/60 will be slower than 720p30/60 of course but obviously your timeline timebase will influence your choice.

On the Mac one can shoot 720p60 (normal) and use Cinema Tools to reflag it as 30p/60 or 24p/60 and your still getting a "true" rather than "blended" or "interpolated" slow motion. One might have to convert to an I Frame codec such as ProRes for Cinema Tools to handle it.

So are we all agreeing that it's 720/30p S&Q to 60fps, shutter 1/250th and higher?

When shooting (video ...) flying birds and not wanting slomo playback, I sometimes shoot 720/50p, which seems to give smoother movements. All wingbeats will be shown with twice as many pictures.

Will I get strange results if I put this footage on on DVD, having it broadcasted or something like that?

If I slow such footage down in post, will it be of noticably inferior quality than if recorded in slomo 50p?

I did a test where I shot a scene at 1080 30p and the same scene at 720 60p. I then edited them both into a 1080 project, and the 720 (enlarged to 1080) was noticeably softer.

So I can't see using the sony's slo-mo in a full HD production.