Image Sequence Output Distorted
by D. Scott Dobbie
on
May 22, 2009 at 4:37:11 pm
Pardon a little "story," but I'd like to understand the "why" something happens so I can better deal with it next time, rather than just hearing a simple fix.
Bottom line is I'm looking for the correct settings for an Image Sequence Output.
Using FCP 6.0.5, I'm looking at footage that was shot at 720/24p on an HVX-200.
The Browser says the Frame Size is 960x720. Yet I know that's not really correct and, I think, has something to do with anamorphic. The Compressor says DVCPRO HD 720p60 (though not sure why there isn't a 720/24p option). The Canvas requires a simple check of the "Correct For Aspect Ratio" for the picture to display properly. I don't understand it all, but it works.
Here's the problem: From the Timeline, I Export > Using QT Conversion... > Image Sequence. And, of course, the distorted version is output. There is no simple selection, like I'd expect, to "Correct For Aspect Ratio." I'd LOVE to see that option. The Default Settings don't give the desired result (trying TIFF). Same if I use the JPEG settings.
And if I Export > Using Compressor, I get the option (though it's buggy and the numbers keep reverting or changing) to select the actual dimensions that I'd like for the final product. Problem is that I don't know what those dimensions really are. The closest preset I can find makes the image look just a hair "fat."
I do have Adobe CS4, so I could make adjustments there, I suppose. But I still would want to know what the dimensions should really be. I don't want to just "eyeball" it and think it looks correct.
Re: Image Sequence Output Distorted by Dave LaRonde on May 22, 2009 at 5:15:46 pm
[D. Scott Dobbie]"...The Browser says the Frame Size is 960x720. Yet I know that's not really correct and, I think, has something to do with anamorphic...."
Well, it actually IS correct, and it does indeed have to do with anamorphic.
The way TV guys do anamorphic is pretty simple: pretend the pixels aren't square, but wide.
The camera's lens squeezes down the 16x9 image onto a 960x720 square-pixel sensor. Since this is an established resolution that tells many applications, "Hey, this is animorphic stuff, okay?", the applications show it in the proper PIXEL aspect ratio, resulting in an image in the proper SCREEN aspect ratio. If you think of a square pixel having a pixel aspect ratio of 1, and a tall 'n skinny pixel having a ratio of 0.5, a wide anamorphic pixel has a ratio of 1.33.
[D. Scott Dobbie]"...From the Timeline, I Export > Using QT Conversion... > Image Sequence. And, of course, the distorted version is output...."
Yup. That's because you're viewing the image as it it was in SQUARE pixels. It's not -- the pixels need to be dispolayed so they're wider than they are tall, right?
I would have thought a DGA guy would have this Camera 101 kind of stuff down cold. The non-union world sez, "Hello-- don't get too compartmentalized!"
[D. Scott Dobbie]"...if I Export > Using Compressor, I get the option (though it's buggy and the numbers keep reverting or changing) to select the actual dimensions that I'd like for the final product..."
The big question is this: how will this final product be used NEXT? Is it for the web? Web viewers like square pixels. Pick a horizontal & vertical resolution that would be 16x9 IN SQUARE PIXELS. 1280x720.... 720x405... 480x270... what have you.
Since we don't know how you'll use it once it's left Compressor's tender ministrations, it's tough to give you a straight answer.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Image Sequence Output Distorted by D. Scott Dobbie on May 22, 2009 at 5:21:55 pm
Dave, that's great! Did not know this all went back to the square pixel idea. I've just never had to mess with it before, so never fully understood. But now I do.
