Tom Brooks
Forum Replies Created
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Jeremy,
Has there ever been discussion of somehow standardizing the posts for this kind of question on the Cow? I would like to have this info in a post where I know I can find the definitive answer after an update comes along. Maybe there could be a form to fill in with info on features, plug-ins, and other stuff that works or doesn’t work with the update.
-Tom -
That’s normal because the anamorphic format uses a non-square pixel aspect ratio to get the 16:9. What are you trying to do with the exported file? Your use will determine how to proceed.
You’ll need to tell most video apps that the file is anamorphic in order for them to interpret it correctly.
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It could be either DV, or DV50. You could use Log and Transfer (FCP 6) and then check the format of the items that are captured.
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[Sean ONeil] “Well after the conversion there’s only one field so there’s nothing to combine. The Kona conversion omits the other field. So you are left with sixty “half-frames”, which when played back properly becomes 540p at sixty frames per second. The full 60fps is maintained but it is only half the resolution of 1080 lines (although in the case of converting from 720p, it would be more like 2/3rds the resolution). Note that the FCP Canvas uses the same method during playback – it omits every other field (cutting the res in half) so you never see jaggies. Does it with SD as well.”
The Kona makes fields of half the resolution of the frame–60 per second. These are the same fields that are broadcast daily on the networks that use 1080i. It’s 1080i the way it is designed to be. The way those fields look on your TV depends on the type of TV and the type of deinterlacing it employs. The Kona is not omitting anything, just reformatting. The Kona is not creating a progressive format (540p), it is creating a 1080 line interlaced format as expected.
Your description, in a roundabout way, describes the shortcomings (and advantages) of all interlaced formats when compared to progressive formats of the same frame rate. Interlacing is a way of reducing the bandwidth that must be broadcast while maintaining the perception of high resolution.
A progressive display, as almost all are in the age of HD, has to deinterlace the 1080 60i stream to achieve, as you say, proper playback. Here’s where bob, weave, motion adaptive, and motion compensated deinterlacing methods come into play. Your description of the 1080i conversion done by the Kona as 540p describes a simple bob deinterlacing method. The Kona is obviously not DOING that deinterlacing. That would be done by a progressive display device upon playback of the 1080i program. The FCP Canvas uses this simple “bob” deinterlacing unless it is set to 100%, in which case I guess it changes to a simple “weave” (hence the comb or “mouse teeth” artifact).
Wikipedia’s (go to Poynton if you like) article on deinterlacing says: “The best deinterlacers combine all of the methods mentioned above. The fields are bobbed, so the frame rate is then kept. Motion compensation is done. In the areas that it cannot find a motion match, it falls back on selective blending.” That’s why 1080 60i looks better on an HD monitor than it does in the Canvas–better deinterlacing.
I personally have to “let 1080i be 1080i.” From there I can think about how various devices handle the interlaced format.
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Interesting thread guys. I did a similar test some months ago and found the same results. I have to say Sean’s tests were more elegant than mine, though. Anyway, the result was that FCP throws away every other frame from the 60P and the Kona maps each frame to a field in 29.97i. Please let us know how the Fieldskit method turns out.
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Good news. We’ll see how fast they can get to Kalamazoo some day.
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Great post. As always, thanks. I’m sure they’ll work out the problem with input like this. Community works!
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As long as you’re going for the white background, you can’t lose the second way. Maybe the only thing to keep in mind is that any movement of the camera at all will result in slight variations in the background which will have to be encoded in your compressed output. –If that’s any issue. A locked-down shot might help keep you away from banding and blocking issues if you’re going to DVD or other compressed output in the end.
By the way, the YouTube clip looked pretty decent, but the lighting could have been snappier on the face. You’ll also find that hair light and backlight in general don’t work the same way against a white background. Any highlights on the edge of the talent blend with the background. Just a heads-up!
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I’ll jump in, since I’ve recently shot something similar for a corporate message.
Green screen pros:
You can shoot in a small studio. Basically all you need is a flat green screen big enough to cover the size of the talent. No matter if you see lights and other stuff on the edges, as it will be garbage matted anyway. Good green screen lighting is needed of course–both on the green wall and the talent–in order to pull a good key.The background can be computer generated in any way that you like and it will be completely noise-free and static if you want. This is good for encoding MPEG and other compressed formats.
You can change out the background any time you like.
White backdrop pros:
Easier edit. No tweaking the key.In our shoot, we were going to a pure white backdrop. We shot in front of a white cyc and let the wall clip a bit. We then used a feathered mask around the talent and replaced the rest of the background with a white solid. Sort of a hybrid between a key and a straight cyc shoot. It was a compromise used to avoid having to paint the cyc green on short notice. My preference would probably be the green screen in most cases.
Progressive is probably a good choice with the HPX-500. Which format depends on your final output.
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Yeah, I totally agree with the other posts. It’s a whole list of things that bring that subjective “look.” Lighting and exposure are very important. The 200 has a smaller sweet spot than more expensive cameras. If you give it enough light, it can look pretty great. The gamma curve you select has a big influence. Detail setting. This camera has a lot of settings to tweak, so you really need to get familiar with all of them and find out what gets you the look you want. There are a couple of good books and DVDs on the basics.
And the monitor is very important too. The HVX200 won’t make your eyes light up until you see the results on a proper HD monitor. I use a Panasonic pro plasma that looks pretty good. It’s a good quality plasma for relatively little money. True, it scales all formats, but it does a good job with the progressive stuff.