16:9 Real World Result with PD's and VX's

[Chris Barcellos]

I'm not trying to "dis" anybody in this theoretical discussion, because each of us uses practical solutions for our needs. I'm just trying to get the theory through my thick head. This is DV for dummies. So the way I see the 16:9 this is as follows:

1. DV was originally developed as 4:3 medium. 720 x 480

2. As it became popular, someone decided 16:9 should be available in the format, so a something was devised to work that into the same envelope. What that was, I don't know. Because we still have the same number of pixels wide, right?

3. So Sony doesn't want to change its chip, but wants to give its VX2K and later users 16:9 wide screen selection, so it does some kind of electronic magic to widen the existing pixels so it will cover a wide screen if selected. That produces a resolution issue, with some of us.

4. Other cameras, including some Sony models also have a native 16:9 chip. So what actually happens there ? Are the native "pixels" wider, or are there just more of the same size pixels anyway? If the latter were the case, then you would have more electronic interpolation to bring it back to 720 wide.

5. So now, you have this 720 wide file still, that you need to show on a 16:9 monitor. So from what I understand, there is a "flag" in the file that says: "Mr. Signal reader, you need to send me out as 16:9 so the 16:9 TV can get see the video in proper aspect"- and that also tells the modern 4:3 TV to add letterbox stripe top and bottom. Older TVs don't have that capability, so you end up with a "tall effect" in the video output. So what I gather happens there is that 720 field is stretched wider. So that means the signal that was originally recorded was actually squeezed into the narrower 720 width, with some kind of magic that saves the quality we associated with the native 16:9 capture.

Can anybody comment or dispell any of the presumptions in my 16:9 For Dummies process or add to the pixel width question ?

[Robert Martens]

I think that's mostly correct, but I'm no engineer, so I fail to grasp the really intricate details of how these procedures are performed.

NTSC DV is, in my understanding, always 720x480. What makes it 4:3 or 16:9 is the pixel aspect ratio. With 4:3 NTSC, it's .9:1, or thereabouts (it goes to several decimal places, I don't know the exact value) meaning that the pixels are .9 units wide for every one unit they are tall. When you use 16:9, however, the same number of pixels is recorded, but the pixel aspect is set to 1.2 (or something similar, don't quote me on that number), meaning they're wider than they are tall. A device capable of receiving this information and correcting for it will do so, but a 4:3 TV that cannot distinguish between pixel ratios will show a 4:3 picture at all times, regardless of how the footage was recorded.

As for native 16:9 cameras, I think the sensors simply have more of the same shaped pixels. The footage still gets recorded at 720x480, but the finer resolution of the chips provides for a better image (I think downsampling is easier and better looking than upsampling, in most situations).

And yet other cameras, like the PDX10, have 4:3 chips that have more pixels than most; I think that model boasts a one megapixel still photo capability. When taking photos, the PDX10 (and TRV900, by extension) uses the entire chip, and the entire megapixel's worth of resolution. When recording 16:9 DV, it can simply capture data from a wide area and record that. In other words, the chip may be 4:3, but it has more than 720 pixels across its width, and those can be used to generate better looking widescreen footage than this camera can. The details of which and how many pixels are used on the PDX10 for this, however, are a mystery to me, I have no first hand experience with the camera.

[Chris Barcellos]

Thanks, Robert. The .9 Pixel reference I see in some editing and rendering situations now makes sense.

[Troy Davis]

Hello,

I mistakenly (don't ask me how:)) shot a video shoot this past weekend with one cam (vx2000) in 4:3 mode and the other (vx2100) in 16:9 mode. Are there any suggestions on how to match this in post using a Sony Vegas? I've tried adding running a script that places the black bars at the top and bottom, but of course since I didn't shoot in 16:9 it cuts off the top of some of the video. Is there anything that can be done?

Thanks,
Troy

[Chris Barcellos]

If you want all in same aspect, you are going to have to open a project (at least in PPro) in the aspect you want, and then trim the non conforming footage. To try to squeeze the footage one way or the other will result in distortion of the non-conforming footage.

[Jay Heard]

I'm going to shoot in Nepal and would like to take advantage of the panaramas shooting with a PD150. Is the quality diminished by switching to 16:9 or is it just a "cut off" picture? Should I consider shooting Progressive?
There is no electricity to charge batteries and although I plan to shoot sparingly I won't be able to charge for 20 days- I'm going to try a Brunton Solarport 4.4 - has anyone tried charging with one?
Any ideas (short of a different camera) for shooting in a remote, cold area?
Thanks
Jay

[Don Bloom]

can't help on the battery situation but the 150's 16:9 isn't a real 16:9-it simply crops off the image and frankly I don't like the way it looks - seems like it's not a sharp as the 4:3
As for PROGRESSIVE the 150 doesn't shoot REAL progressive except at 15FPS (NTSC) so as long as no one is moving I guess you could use it.

Why not mark the LCD with the 16:9 crop lines (top and bottom) shoot 4:3 and crop it out in post-as for progressive perhaps do that in post as well.

I love my 150 (had 2 at one time) BUT for the way you want to shoot probably not he best choice.

Don

[Chris Barcellos]

You can also use an 16:9 mask in camera to create the 16:9 letterbox in the 4:3 mode.

[Jay Heard]

thanks - jay

[Tom Hardwick]

Forget the progressive scan as it simply turns the PD into a motor-drive still camera. At 12.5 fps (PAL) it's not much use for anything else.

The 16:9 mode is surprisingly good, as it's using an electronic anamorphic compression and not simply cutting off the top and bottom of the picture. If you view the results on a 4:3 TV you see it letterboxed with no loss of resolution at all - but if you expand that to fill the screen of a true 16:9 set, then yes, the picture does get a bit softer.

You talk about 'panoramas', but don't forget that in the switch to 16:9 you lose wide-angle coverage (diagonally) so you'll need a wide-angle converter.

I'd say that the PD150 is a fine camera to take into difficult climates and conditions. It was taken into every war zone going and came out triumphant. I'd take lots of NPF-970 batteries, though.

tom.

[Chris Barcellos]

Progressive Tip:

You should experiment with it before you depend on it, but there is a way to the Digital Effect Flash mode to get a pseudo Progressive with the VX and PD cameras. See this thread for full explanation. It is pretty interesting. See posts 5- 15 for discussion and use.

http://www.dvinfo.net/conf/showthread.php?t=84045

[Bob Hart]

My personal preference would be to put a safe area mask on the LCD screen to keep your framing within the preferred area and shoot 4:3. This gives you a little forgiveness for re-framing in post.

Don't use sticky on the LCD screen itself. Shoot everything as pure and unaltered as you can. Don't mess with any effects at all. This is a rare and costly event you are doing. You can put salt in the stew but you can't take it out.

Electronic widescreen works okay. The Century Optics 16:9 anamorphic lens works better but it is an added weight, can become skewed and I would also have some anxieties about CA when shooting with bright snow, dark rocks and sharp edges in background.

You also have to be vigilent about corner cropping on the widest end of the lens so in your situation where simple is best, I would leave the 16:9 anamorphic at home and take the resolution hit.

For the wide panoramic views I would be inclined to cover the identical shot twice, one with a human in it to establish scale and one without. A human in the shot will also tend to distract the viewer from inferior resolution which is most observable in the highly textured and contrasted wides.

There is the "Over Land and Under Water" thread furthur down in "Special Interest Areas". Ask for some advice there. Those people really know what they are doing in wilderness imaging and will surely give you some good advice.

The principle questions I would ask are how to deal with the snowcaps and high contrasts (UV and polariser filters?), white balance, ultra-violet light, batteries in cold evironments, camera acclimatisation methods, lens care.

If I was going to take an accessory lens, it would be the wide-angle adaptor for the Sony or maybe even a fisheye.

On 12.5 fps progressive. If you do not have movements happening close to the camera in the frame and the camera is locked off on a tripod, I would say "why not?" in selected situations but get normal interlace coverage as well for the same shots.

[Barry Richard]

cropping also compromises resolution

I've had decent experiences using the electronic 16/9 -- it doesn't from my eyes appear to apreciably harm the sharpness --

If you are certain to end up with 16/9, I'd shoot that way using the electronic mode (but test yourself to see if you agree.)

NP970s are fairly light and cheap -- pack as many as you think you'll need. Does that solar charger weigh much ?? (BTW -- I've bought an NP970 cheap at a street camera shop in Saigon a year ago).

BTW -- Sony made a little known accessory light that worked on the VX2000 -- (never tried it on the PD150, though I bet it does) Incredibbly tiny, it gets powers off the main battery through the powered hot shoe. Diffused with tough spun, it makes an incredibly useful light for situations such as you'll be in.

good luck...

[Bob Hart]

I am not advocating against using electronic 16:9 for resolution reasons alone. It is true cropping in post also introduces a resolution hit.

My recommendation for using 4:3 with a safe area mask for 16:9, is to enable vertical re-framing options in post where for whatever reason, the vertical framing of the shot might be off.

After scuttling up and down mountain trails or riding hot crowded buses, there will be a fatigue factor in play which can diminish the skill set.

If there is some extra image area to use for later enhancements like re-framing a poorly composed shot or stabilising an image which is all shook up due to muscle tiredness, then that is the option I would prefer to keep.

Most times, I use the electronic 16:9 option.

[Chris Barcellos]

Okay. I've been hammered a few times for indicating that I have gotten decent results shooting with my VX 2000 in 16:9 mode and combining with FX1 footage in 16:9, in an SD format. I'm trying to rectify those comments with my experience.

Of course, the first thought is my standards are not high enough, and that may be the case, I tend to shoot for family, friends and school functions, etc.

But I still think there is more to it than that, and I am postulating my perception is the result of the following. I am wondering if Boyd Ostroff and others with more experience would tell me where I am wrong:

1. I have been told that the 16:9 coming from the Sony VX and PD only has a resolution of 380 vertical lines. I understand and believe that. It is painfully obvious on the computer in editing programs, and when played from .avi of direct capture on my computer monitors.

2. What I have experienced though, is that when I output this material after editing to DVD, and play it on a standard definition television, the difference between a dedicated 16:9 chip camera and the PD is much less obvious. It may even be negligible.

3. I postulate that this is due to the fact that (unless my understanding is wrong) the actual vertical resolution of letter boxed material on an 4:3 standard definition television would be around 360 lines.

So is the reason that I do not notice much difference in my finished DVD material due the fact that the 480 lines from the dedicated 16:9 chip have to be downrezed for display on my standard definition TV.
Or what.