a couple HD questions

[rando]

I have a GY-HD100 and I just started using HD. I have a couple questions 1. Has anyone noticed that the frame rate looks a little screwy on HD? kind like the shutter speed is being drug? Is that normal? Should I try to compensate somewhere like in ProCoder? 2. I use 720p should I edit in 720p and export to BR 720p and let the t.v.s scale it to 1080p or should I take my 720p footage and use Procoder to export it to 1080p(i)?

[antonsvideo]

progressive is for cinema :) and yes, it looks jittery

are you producing in order to convert to film?

[STORMDAVE]

Progressive will always look progressive. If you want the video look, you should shoot at 60p with your camera.

I don't recommend upconverting your footage, just edit in 720p and output at 720p.

[rando]

I have 720p 30 and HDV-SD60p which one should I use. I do weddings and would like a video look.

[antonsvideo]

i am not familiar with this camera

but to get the video look, you need i clips instead of p

i = interlaced

maybe try a different project setting?

[tingsern]

Don't quite understand why progressive would be jittery in the first place?

I have been filming weddings on HVX202 using 720p - and they looked perfect to me. Shutter speed is 1/60 second. Aperature settings depending on lighting levels. And of course, fill light as well.

I suspect it is the technique of filming that lends to jittery scenes. You have to pan (if at all) really, really very slowly. Don't zoom while the camera is recording ...

The wedding scenes look like - well, cinemascope :-).

[GrassValley_KH]

Don't quite understand why progressive would be jittery in the first place?

I'm sure Brandon has a better explanation (complete with analogies), but in short, unless you are shooting 50p or 60p, progressive footage will be jittery compared to interlaced footage. Shutter speed, cadence and pulldown all play their hand in things here too.

When shooting progressive, there are certain rules of cinematography that need to be obeyed. Focus, panning, lighting. Break them and you end up with footage that looks horrible, and no amount of post is going to fix that.

[GrassValley_BH]

It's not so much the p vs i, but the sampling rate - the majority of progressive formats are 25p or 30p. This means there are 25 or 30 full frames sampled per second.

This means there are only 25 or 30 temporal samples.

Meanwhile, the majority of interlaced formats are 50i or 60i. This means there are 50 or 60 half-frames (fields, or interlaced half, not "chop it in half" half) sampled per second.

This means there are 50 or 60 temporal samples.

More temporal samples = smoother motion.

Imagine a flip-book (hopefully you all had flip-books when you were children) showing a specific scene (maybe a car driving by). The more pages the flip-book has, the smoother the motion of the car will be.

Ideally, you'd have high sample rate (50/60) and progressive samples, meaning 50p or 60p, but it results in a high data rate.

[tingsern]

While I agree that 50p or 60p will be ideal (rather than 25p or 30p as of today's) - all the film cameras (using Kodak's 35mm films) only shutter at 25 or 30 picture frames per second. There are no film cameras going at 50 or 60 frames in general use (not talking about those purpose made high speed motion cameras).

It is basically a technique of filming at 25/30 frames per second - you basically have to treat the video camera as a film camera rather than a video camera. It works beautifully - no jitters in my case.

Just don't set the camera shutter to 1/30 or even 1/15 - use 1/60 and it works nicely.

[Shaheen]

This was extremely helpful.. than you all..
I have been going back & forth with this issues & thinking it was my fault.
We usually film our HD projects in upper field order with 1440 x1080 frame size & 25 frame rate & my project setting matched this setting, the result is always perfect on Blu-Ray discs & on DVDs (Authoring in Encore)
But in 2 cases the camera men wanted to film in progressive, same settings above only in progressive field order thinking we will get better quality..
so I couldn't get rid of the jittery play back no matter what I did, from project settings to different export methods..
Now because of this thread I know that it's not my fault & we shall never film in progressive again unless we have the time to film it the way it should be filmed.. We mostly shoot weddings so not much time to take full care of the cinematography side..
Again thank you all
Shaheen

[Bluetongue]

While I agree that 50p or 60p will be ideal (rather than 25p or 30p as of today's) - all the film cameras (using Kodak's 35mm films) only shutter at 25 or 30 picture frames per second. There are no film cameras going at 50 or 60 frames in general use (not talking about those purpose made high speed motion cameras).

It is basically a technique of filming at 25/30 frames per second - you basically have to treat the video camera as a film camera rather than a video camera. It works beautifully - no jitters in my case.

Just don't set the camera shutter to 1/30 or even 1/15 - use 1/60 and it works nicely.

Not quite so
Remember old 8mm and super 8 film ran at 18 frames per second but looked acceptable, WHY
Although it was filmed at 18 frames the projector had a shutter that showed each frame between 3 and 5 times depending on the projector tricking the eye into seeing smooth motion
The more expensive projectors used a larger globe and more frames
The same goes for films in a theatre, look pretty good but pans can still get jittery
Some TV sets have 100 to 300 htz refresh rate to smooth the action by doing the same, so it also depends on the capability of the viewing projector / TV as to how good the movement is
For me I will keep to "Interlaced"

Regards Barry

[Bassman]

But in 2 cases the camera men wanted to film in progressive, same settings above only in progressive field order thinking we will get better quality..
so I couldn't get rid of the jittery play back no matter what I did, from project settings to different export methods..
Now because of this thread I know that it's not my fault & we shall never film in progressive again unless we have the time to film it the way it should be filmed.. We mostly shoot weddings so not much time to take full care of the cinematography side..
Again thank you all
Shaheen

I would not throw progressive shooting under the bus... What you are noticing is the framerate. Slow the framerate and the camera movement will beat the number of frames going by and cause judder. That is what everybody is seeing. Shutter speed has more to do with blur or sharpness with the motion.

Interlaced is a "trick" invented a long time ago to make a slower framerate have the appearance of a faster framerate. It is half of this and half of that 60 times a second. Now that we have the tech, a progressive frame with the motion you desire is better in the long run imho. But software does a fine job of working with both formats these days.

You have a choice of 24p, 25p, 30p, 50p, 60p.

DVD forces all footage to be interlaced but Blu-ray gives the choice of progressive or interlaced. Our HD TVs are progressive devices so it makes sense to me to keep the signal progressive all the way through.

Rando, your model of camera only offers 24p & 30p. It does not go to 60p. But I remember seeing something about an interlaced mode that was added. Check out the JVC forum on DVinfo.net