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AJA io HD aspect ratio conversion

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Grant Peacock
AJA io HD aspect ratio conversion
on Sep 8, 2012 at 10:39:56 pm

I am finally recovering some of my best shoots from 4:3 BetaSP, running the playback through AJA io HD. I'm very pleased with the look when I ask the unit to upconvert to 1080i, using component video as the source. (My BVW-D600 lives on!)

With testing, the best way to get to 16:9 from 4:3 seems to be going to ControlPanel and under the Format area, choosing 'Zoom Wide'. This is great for my b-roll, but is not good for interviews - I was not excessive with headroom framing to begin with, and the talking heads are now cut uncomfortably at the top end.

Am I doing the 4:3 -> 16:9 conversion in the best way, or are there other opportunities to do it better elsewhere? I can imagine an argument to send the video straight through to SDI, and then deal with the ratio conversion in another way.

I could also see the argument for doing 2 types of conversion - 1 strategy for b-roll, and another for talking heads, where preserving the margins of the frame are more critical.

Amazing piece of gear this - first time using it - very impressed!

Grant.


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Shane Ross
Re: AJA io HD aspect ratio conversion
on Sep 12, 2012 at 12:03:14 am

I always capture 4:3 as PILLARBOX. So I can then reposition each shot to fit where it looks best.

Shane
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Read my blog, Little Frog in High Def


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Grant Peacock
Pillar box for aspect ratio conversion
on Sep 12, 2012 at 6:25:33 pm

Thanks Shane,

I've learned quite a bit about the AJA Control Panel since I wrote this post. Finding it super convenient to just keep flipping between my now-saved presets.

It's amusing seeing what I was putting up with in 2009 - in one 60 min burst of network live and as-live interviews, I could be flipping back and forth in my BVW-D600WS between 4:3 and 16:9, over and over again. I'm willing to bet that somewhere along the way, my shot went to air with the wrong aspect ratio. It must have happened once!

(One of my best tips for anyone new to AJA IO HD is that it should be 'on first - off last'. As soon as I started doing that, everything has behaved well*.) I am getting to used to shutting down the Mac multiple times per day, in order to stay on spec with this operating rule.

On the aspect ratio conversion - there's a technique that is popular with some - replicating generic portions of the 4:3 background, blurring, then doubling it up into the newly created void when the 4:3 image is introduced without scaling to the 16:9 view. Personally, I find the result weird and distracting. I would not use it. If you've seen it, you might also find that the most objectionable part is the hard vertical edge between the 2 zones.

One other method that looked promising - I found a well laid-out tutorial in YouTube - I'm including the link, because I think it is worth consideration if you are a PhotoShop user :







The core of this method is a controlled set of spherical distortions of portions of the image, oriented vertically and horizontally. Lance Campeau courageously chose 'worst case' footage - a freight train tracking through the test shot.

If an equivalent method could be developed for Final Cut, and it may well be possible - this would be a great choice. My prime 4:3 footage that I would wish to 'modernize' is interviews - nearly always the same talking head framing. A much less challenging conversion, I think, due to the lack of motion around the edges of the frame, and the relatively static content of the entire image.

(I am finding that b-roll is generally passing right through from 4:3 to 16:9 with an acceptable look, keeping that part of the transfer process simple).

The upconvert opportunity presented by the AJA io HD is amazing. Using component level video, camera original (or 2nd generation), you've got something very nice to work with. There must be some 'heavy math' at work inside the box, as it constructs a 1080i signal out of SD BetaSP! I've passed along my congrats to the team at AJA.

Grant.

* I was getting 'hardware missing' errors before adopting this practice. I have not seen one since.


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