Why shoot 60P?

Rich Parry wrote on 1/15/2015, 11:43 PM

I bought a Sony FDR AX100 a few months ago and I’m very happy with it. I shoot amateur landscape and wildlife video at XAVC S HD (1920x1080 @24fps) quality and it looks good to me. The camera also shoots 60P, but since I always render to 24P, it never occurred to me to shoot 60P.

I’ve seen a few posts here saying 60P is the preferred configuration, so I wonder if I am missing something? If I will always render to 24P, what is the advantage of 60P?

I understand 60P gives more flexibility is slowing down and/or speeding up video and I think it is more stabilizer friendly, so in the event I have to stabilize the video, having more frames to work with is a good thing.

So besides changing playback speed and stabilization, is there some other reason to shoot 60P? If I’m going to render to 24P, wouldn't a 60P clip have more ghosting due to the need to either “resample” or “drop” frames.

I realize I can test this myself by shooting 24 and 60 fps, but I don’t trust myself to know what to look for.

Comments welcome?
Rich

Comments

PeterDuke wrote on 1/15/2015, 11:54 PM

If you have medium to fast motion, you will get much smoother action with 60p. I hate the judder you get with even modest pans with 24p, but some film buffs claim that it helps give a genuine film look.

The world is going progressive (TVs, Computers, cinemas) so interlaced presents a deinterlace problem. Unfortunately interlaced is used for TV transmission and DVDs. Blu-ray discs in full HD can only be 60i, 50i, ot 24p.

If you shoot 1080-60p you can easily convert it to 1080-60i or 720-60p if needed.

Geoff_Wood wrote on 1/16/2015, 12:15 AM

Surely the question should be "Why am I rendering to 24p ?"...

;-)

geoff

ushere wrote on 1/16/2015, 12:56 AM

...a genuine film look

boy am i tired of this statement (no offence intended). if you want a film look, SHOOT FILM!!!

even now i can easily discern video pretending to be film in 'lower end' productions. that said, most people wouldn't even know or care.

John_Cline wrote on 1/16/2015, 1:08 AM

There is a LOT more to achieving a film look than just shooting 24p, in fact, 24p is pretty much the least important factor.

farss wrote on 1/16/2015, 1:32 AM

[I]" If I will always render to 24P, what is the advantage of 60P?"[/I]

Why are you always rendering to 24p?
Rec 2020, the standard for 4K Broadcast, supports frame rates up to 120fps, the BBC has made a case for 150fps for Region50.

Bob.

pilsburypie wrote on 1/16/2015, 4:17 AM

Being in PAL land I used to shoot 25p - now I shoot 50p and any motion looks so smooth. Watching 25p or 24p now almost makes me feel epileptic. Even at the cinema I have to try and seek out the HFR.

Won't be long before 50/60p is standard

Kimberly wrote on 1/16/2015, 4:44 AM

In 2013 and 2014 I was shooting 1920 x 1080 24p. For 2015 I switched to 1920 x 1080 60p, which I render down to 1280 x 720 60p for Blu-ray and the appropriate spec for NTSC and PAL DVD.

The 60p is nicer for motion. On the BD it looks super crisp and it seems my color is "better" although that is subjective. I'm shooting underwater and I cannot explain why the 60p seems to white balance more easily than 24p, but it seems to be true.

I did like the 1920 x 1080 24p because it is a BD spec, which I'm guessing is why you like it too. But the 1280 x 720 60p looks really nice so perhaps you should give it a try.

diverG wrote on 1/16/2015, 7:07 AM

Like Kimberley I also work in 1280x1080 (50P) as the final output is to BD. However I set the camera to record in 1280x1080 so no downsizing on the timeline.
Less pixels=faster render times.
I'll certainly use this setting unless there is a new BD spec released. Not holding breath.

Geoff

musicvid10 wrote on 1/16/2015, 8:06 AM

If you're going to shoot 60p, don't deliver 24p. Deliver 30p instead -- it's the only thing that makes sense.

diverG wrote on 1/16/2015, 9:07 AM

@ muscic,
Sorry. Not trying to be funny but having a senior moment here. Deliver for what at 30P? If you shoot at 60P is it not better to deliver at 60P.

Maybe it's because I live in PAL land. my choices are 24P or 50P for BD.. Obviously there are other options for interlaced. For 'international' BD's I would shoot 60P.

wwjd wrote on 1/16/2015, 9:16 AM

Blu-Rays can do 60p at 720??

OldSmoke wrote on 1/16/2015, 9:24 AM

Blu-Rays can do 60p at 720??

Yes they do and it looks great! You will be hard pressed to see the difference to 1920x1080i in terms of resolution but you will notice the smooth motion.

Laurence wrote on 1/16/2015, 9:51 AM

60p is not all positive. The shutter speed is twice as fast as 30p so you need more light. If you drip every second frame for computer playback, you can get juddery looking playback.

Like a lot of people, I use 30p as my go to frame-rate, but will shoot 60p or 60i if I know that I am going to want to use a slow motion effect in the final edit.

On the other hand, the short shutter makes 60p stabilize with Mercalli exceptionally well.

Zelkien69 wrote on 1/16/2015, 10:50 AM

30p isn't an acceptable spec at 1080 for Blu-Ray delivery. We've been filming at 30p and delivering 60i.

Laurence wrote on 1/16/2015, 11:58 AM

As a final playback format, 30p defined as 30p and 30p defined as 60i look exactly the same. I believe that this is why there is only a 60i format and not a 30p one.

The only time I've had an issue with 30p being wrapped as 60i is when you stabilize with Mercalli 3 which introduces interlace artifacts in the stabilized "30 video wrapped as 60i" output. As a DVD or Bluray playback format however, a 60i works great for 30p.

OldSmoke wrote on 1/16/2015, 12:35 PM

[I] The shutter speed is twice as fast as 30p so you need more light.[/I]

The shutter speed is the same! There is no way you can record 30p at 1/30 unless you take a completely still scene, no motion at all.

[I]60p is not all positive[/I]
I see it the other way round; "It is all positive!"

musicvid10 wrote on 1/16/2015, 1:37 PM

diverg,
OP never said he was delivering BluRay, and I was responding to his thread topic, not your reply.

This is a perfect storm of interjecting an off-topic question into the discussion and expecting a tailor-made response. It is also a perfect reason for starting your own thread, thanks so much. As others have stated, 60p to 60i BluRay is the logical choice, . . . but only if that is what you are delivering.

Regardless of the OP's destination format, 60p to 24p does not a smooth output make. That should be perfectly obvious.

farss wrote on 1/16/2015, 1:42 PM

[I]"The shutter speed is the same! There is no way you can record 30p at 1/30 unless you take a completely still scene, no motion at all."[/I]

The normal shutter speed for 30p is 1/60th and the normal shutter speed for 60p is 1/120th. You lose 1 stop of light shooting 60p compared to shooting 30p.

Bob.

Laurence wrote on 1/16/2015, 2:04 PM

Could you use a 1/60 shutter speed on 60p? I know it isn't the conventional wisdom of half the frame rate, but I don't see it mattering as much as it would at lower frame-rates.

OldSmoke wrote on 1/16/2015, 2:05 PM

The "normal" shutter speed of any camera I have used for recording 60p is 1/60.

That is the shutter speed you get the moment you set the camera to 60p for HXR-NX5U, HXR-NX3, HF-G30 and AX100. It is even sufficient for recording figure skating.

Laurence wrote on 1/16/2015, 2:40 PM

I'm a big believer in testing things yourself and going against the conventional wisdom when you like what you see. For a fast moving sport like figure skating, 60p would definitely be better. I would try it with the 1/120 shutter speed though. The motion blur at 1/60 would be more than you really want. I would do some comparing of shots with 1/60 and 1/120 shutter speeds to make sure your results are the best they can be.

OldSmoke wrote on 1/16/2015, 3:27 PM

Laurence

It will sure be better at 1/120 but that is no the point I was trying to make. If 1/60 is good for 30p it is certainly ok for 60p and hence you don't lose an f stop. It is not a MUST to record 60p at 1/120.

farss wrote on 1/16/2015, 3:35 PM

For sure in most cameras you can turn the shutter off.

However your previous statement was that you cannot do that unless the subject is stationary.

"There is no way you can record 30p at 1/30 unless you take a completely still scene, no motion at all."

I have shot 25p with the shutter off but mostly restricted to the locked off wide camera. It can work well.

Bob.

OldSmoke wrote on 1/16/2015, 4:12 PM

Bob.

How did that shot look when people where walking in front of the camera?

Laurance
This was shot at 60p, 1/60 because it was too dark to go for 1/120 but it still looks good. You would have to download it to get 60p playback.