But Rich is shooting at 60p, so that obstacle is already in place....

geoff

My goal is to work only with progressive for the best final results.

I have three cameras that I use on a regular basis. One of those cameras gives me a choice of 60i, 60p or 24p. Two of them include 30p as well with one being a low bit rate of *.mp4.

60i is out because I do not want to deal with the annoying problems of interlaced video. 24p is just plain awful!!! So all that is left that gives me what I want on all three cameras is 60p.

It all ends up being 30p for the internet and somehow it is even a type of 30p for DVD and DVDA does not re-compress it.

I have an older camera that stares at the projector screen to record stuff I need once in a great while that is only 60i. I just simply dump that video into the mix with the progressive videos and process it with them without making any changes to it. I am not concerned about doing that because I seldom use it and it always comes out great anyway. I think Hand Brake and Virtual Dub are somehow taking care of that one for me.

The built-in stuff of Vegas can make a video look very good overall but not as good as I want. Certain parts of the videos, especially when they turn off the lights and it is a bit on the dark side, will look very poor.

Starting with 60p video converted to 30p and then using Frame serving to Hand Brake or Virtual Dub gives me the superior results that I want and that is all I really care about.

For very low light, I can get a stop or 6db more light by manually locking the shutter at 30. This means that the iris has to adjust for auto-exposure. The only problem with that is if the lights all of a sudden get too bright, the video can get over-exposed. That is because the iris on my cameras cannot block all of the light.

So one needs to take care when locking the shutter. All of that depends on the camera one has. At least I have a way to get more light when the lights are low. Putting a limit on the AGC prevents excessive noise.

So that is why I use 60p with the once in a while included 60i from the one OLD camera that cannot do 60p.

In a nutshell, I shoot, edit and process the videos for the final results.

. . . and somehow it is even a type of 30p for DVD and DVDA does not re-compress it.

How can this be? In NTSC DVD-A the "legal" choices are 30i (29.97i) and 24p? I've never tried this with 30p but will run a test later today.

Kimberly asked, "How can this be?"

Progressive segmented Frames (PsF)

See

http://en.wikipedia.org/wiki/Progressive_segmented_frame

I get the benefits of 30p while using interlaced. DVDA and DVD's think it is 30i but in effect it is actually 30p.

Kimberly asked, "How can this be?"

I didn't believe it myself but yes, it works. It does look like 30p and if there isn't much motion it is acceptable; unfortunately not suitable for my sport events.

@ OldSmoke

In your case it looks like Blu-Ray with 1280x720 60p for your sports videos.

SD-DVD specs are too old for 60p and I sincerely doubt if they will ever be updated for 60p.

So it is SD-DVD 30 or Blu-Ray 60.

@Vidmus

Oh I know. I use 720 60p for BD and 60i for DVD; 30p is not acceptable for DVD because it looks just bad for fast motion.

I just wanted to confirm that 30p does work eventough it is not officially in the spec for DVD. 30p sure looks better then 60i if there isn't much movement in your footage. I did try 30p because of the discussion in another thread here.

You can also mix 30p and 60i in a 60i project. For example, in a sports show you could do interviews at 30p for a little sharper look and the moving sports stuff at 60i for more fluid motion.

"you could do interviews at 30p for a little sharper look and the moving sports stuff at 60i for more fluid motion."

How do modern TVs with a progressive screen generally display interlace video? Are they all the same?

If I were designing a TV I would display say 60i by first converting it to 60p by taking each field and interpolating it, but I would just display 30p as 30p without processing. I would then expect that 30p and 30p flagged as 60i to look different, but I would not know how much.

60i is brighter than 60p.

"How do modern TVs with a progressive screen generally display interlace video? Are they all the same?"

they always have to deinterlace it before displaying it, no lcd/plasma/led/whatever can display interlaced footage as interlaced, like the old crt's did.

i think that the question with shooting 60p is what actually happens when you export the edit at 30p?

does vegas drop every other frame, or does it combine adjacent frames?

does vegas drop every other frame, or does it combine adjacent frames?

It drops every alternate frame and it will look exactly like 30p. For 60i, the odd and even lines will be drop from the respective frames, it will looks as if shot at 60i

60i is brighter than 60p.

And why is that?

60i is brighter than 60p.
---------------------------
And why is that?
-------------------------------
Interlaced is more light sensitive because you are exposing two fields per frame ( 180 deg shutter) for twice the exposure. In progressive mode, you expose one full field per frame, so for the same exposure you need to reduce the shutter speed by 1/2.

This is affirmed in test reviews for video cameras. Take Adam Wilt's review of my Sony PMW-EX1.

Sensitivity

Despite the problems with going from HD to SD DVD using interlaced footage, I shoot stage productions so the light gathering ability is everything.

John

I am not 100% certain, but doesnt the PMW-EX1 only 1280x720 @ 59.94p and only 1920x1080 @ 29.97p? If so, that isnt a good comparision. My AX100 shoots Full HD 1920x1080 @ 59.94p and also 1920x1080 @ 59.94i. I doubt there is any difference in sensitivity if I set the shutter for both recording modes at 1/60 but I am not sure how I would test it with my limitted test equipment.

I tested it, and opted for it, since lowlight event shooting is the bulk of my work. It was significant enough for me to choose it.

However, 60p for landscape, sports, and slowmo is better than 60i for smoothness and jags.

Choose what's best for the situation.

Craftech, thank you for the great understanding of why.

[I]"I am not 100% certain, but doesnt the PMW-EX1 only 1280x720 @ 59.94p and only 1920x1080 @ 29.97p?"[/I]

That's true.

60i is more sensitive than 30p with any decent camera.

The reason is when shooting interlaced line par averaging is used to prevent line twitter. That decreases vertical resolution and also reduces noise. In the EX1 between 30p and 60i the camera gains about 1 stop of light but vertical resolution drops from 1,000 lines to around 700 lines.

Between 60i and 60p nominal shutter speed goes from 1/30 to 1/60 so there's 1 stop, Shooting 60i I assume the camera would employ line pair averaging so that's about another stop. 2 stops is a lot of light to lose.

Bob.

Ok, I like to learn but I am a stubbern student and always quesion my mentors. I don't have much test eqipment but I used my AX100, pointed it against the wall and made sure that illumination is stable by doing it at night, switching off the room light and only use my LED light pointing at the ceiling away from the wall I am pointing the camera at. I used the AVCHD file format for this test because it has both, 60i and 60p. If 60i is 2 stop better, I should see a change the way the camera calculates Iris, Gain and Shutter but there isnt any. Note that the camera natively will select 1/60 shutter speed for 60i and 60p. I then fixed the shutter to 1/125, still both recording modes will have the same iris and gain values. I did see a change when set to 24p and 1/60 shutter speed; the gain went from 18db up to 21db at the same iris setting but it showed the same gain at 1/48 shutter.
My believe is that the AX100 is designed around progressive recording and when recording 60i, it will do what the NLE does, record only even and odd lines from each frame hence there is no difference in sensitivity between 60i and 60p, atleast not on this camera. But, someone with more knowledge will probably disagree?

[I]" My beleive is that the AX100 is designed around proogrssiv recording and when recording 60i, it will do what the NLE does, record only even and odd lines from each frame hence there is no difference in sensitivity between 60i and 60p, atleast not on this camera."[/I]

You're probably correct.
If every row of pixels in the sensor can be scanned at 60Hz there's no need to scan alternate rows to derive an interlaced output.
The only time a camera needs to use line pair averaging is if the lens and OLPF can resolve over around 0.75 times the vertical resolution of the sensor.

You're right, NLEs or at least Vegas, doesn't do line pair averaging when going from progressive to interlaced nor is there any low pass filter , that can cause issues discussed at great length here over the years.

Bob.

So the statement [I]60i is brighter than 60p[/I] isn't always true or is maybe even a thing of the past with recent sensors and processing.

I would like to thank everyone for their responses to my original post. You guys are great.

To those that asked, “Why do I shoot 24P”, my answer is I didn’t know better. I thought that was the “standard”. I work without a mentor and rely on what I read, I guess I was wrong. As pointed out by everyone, video with motion such as a pan look bad, but I just lived with it.

To those that asked, “What is my deliverable”, I should first say my customers are friends and family only and I like to render one (1) file that I can:

1) View on a computer by just double clicking
2) View on my HDTV by putting the file on a thumb drive and inserting into TV USB port
3) View on Vimeo or YouTube by uploading the file
4) I don't make DVDs or BDs.

By rendering 1920x1080P @ 24fps gets me what I want and I've been pretty happy with the results with the exception of jerkiness and terrible pans.

Based on everyone’s responses, I plan to start shooting 60P AVCHD (probably no need for XAVC or XAVC S?). However I haven’t decided if I should render to 60P or 30P. I’m still experimenting, suggestions welcome.

Based on everyone’s responses, I believe that even if I shoot 60P and render to 30P and therefore throw away half the frames, having 60P source video will enhance slow motion and stabilization if that is needed, right?

Rich

I would (and I do) shoot 60p, but then if the final format doesn't permit 60p, or the customer can't play 60p, I deliver in 60i (a.k.a., 29.97 interlaced). Everything can play that, and the pans and fast motion are perfectly smooth.

30p makes no sense, and the panning issues you originally describe will be only marginally better in 30p compared to 24p. The feeling of smooth motion doesn't really "kick in" for most people until you get to somewhere around 40-50 screen updates per second. It doesn't matter if those are interlaced or progressive: the apparent motion is very similar, which is why interlaced works so well.

"30p makes no sense, and the panning issues you originally describe will be only marginally better in 30p compared to 24p."

Which is why 4k is not yet up to par. It can ONLY be shot in 30p.

The other thread asks if we are ready for 4k? I think 4k is not yet ready for us.