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-   -   Creating a ProRes 422 timeline (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/465979-creating-prores-422-timeline.html)

Kalunga Lima November 2nd, 2009 04:55 PM

Thanks Chuck (and everybody else) really, for your feedback. You are right, it isn't a competition, your experience is invaluable. It's so frustrating at times to be earning one's living with technology that has become so complex. Seems we spend so much effort just understanding the "work flow", that we never get to the "work". Seems crazy to introduce all these new codecs without simple and clear guidelines as to how to actually deal with them. You'd think mixing 2 different flavors of XDCam wouldn't necessitate trial and error. Sorting this out cost my project well over a week of editing time before we can actually started to edit. I couldn't imagine doing this without this forum.

cheers to all

Chuck Spaulding November 2nd, 2009 11:45 PM

Quote:

Originally Posted by Simon Ash (Post 1441784)
One last question.
Why is 1440x1080 the same as 1920x1080. I get confused with square and non square pixles.
The thing is 1440x1080 on a 1920 timeline is zoomed 33% to get to 1920x1080 but I cant see any degrade in picture quality, why is this. Or is there some drop in quality to stretch 1440 to 1920 that I cant see.
I thought I had my aspect ratios together.

Cheers

If you open an HDV frame in Photoshop [make sure aspect display correction is off] you'll notice that 1440x1080 is actually a 4x3 image, that's not a coincidence, its a hold over from older ccd's that were being pressed into service for HD. But you should also notice that the image is squeezed, they packed 1920 (which is 16x9) pixels worth of data into 1440 (4x3) pixels. They could do this by using non square pixels. So if you multiply the horizontal 1440 by 1.33 you get 1920.

Interestingly enough, I thought I had this figured out because when I first did this I clicked on the motion tab for the HDV clip the scale was 100% but Distort was -33, which was what I would expect. But when I opened FCP7 to check my explanation the scale was 133 which it shouldn't be because the 1080 is not scaled 33%.

Nevertheless this is really simple to check. Just place an HDV clip into either an XDCAM or ProRes timeline and it will be scaled correctly and you won't have to render to edit.

Simon Denny November 3rd, 2009 02:15 AM

Thanks Chuck for the great advice and info.

I wonder when HD will become the new SD if you know what I mean.

Anyway.

Cheers

Alister Chapman November 3rd, 2009 07:50 AM

Quote:

Originally Posted by Chuck Spaulding (Post 1442015)
If you open an HDV frame in Photoshop [make sure aspect display correction is off] you'll notice that 1440x1080 is actually a 4x3 image, that's not a coincidence, its a hold over from older ccd's that were being pressed into service for HD.

I don't think that's true as it would imply the use of 4x3 CCD's for HD which is 16:9. You can't use a 4:3 CCD and then stretch it to 16:9 as doing so would give the incorrect aspect ratio. I'm pretty sure it came about simply as a way to reduce the bandwidth required to record HD and using the same aspect ratio "stretch" as used for 16:9 SD TV was a simple solution.

Chuck Spaulding November 4th, 2009 10:51 AM

Your probably right, but if you open a 1440x1920 image in Photoshop it is 4x3.

Sony made a big deal about the EXI's being true HD and there were a few 16x9 SD camera's before that. Not even DVCProHD is "true" HD.

Of coarse I'm not sure how much the origins of all this matters, but the good thing is that it has come a long way in a relatively short amount of time.

Ray Ellis August 2nd, 2010 06:21 PM

creating a ProRes 422 timeline
 
Hi,

I found this thread from last year and just wanted to ask one additional question. I also have an hour long FCP sequence that contains both XDCam HD (1440x1080) and EX (1920x1080) clips. I need make a ProRes timeline of the sequence to send out of house for color correction.

Which option yields the best quality picture:

Import a batch file of all my clips into Compressor and use the default setting for Apple ProRes 422 without adjusting any setting in the Inspector. Therefore the settings would be based off the source resolution. When I create my new ProRes (1920x1080) timeline with these new clips the XDCam HD clips will have to be rendered at output.

or....

Import a batch file into Compressor, use the Apple ProRes setting, but in the inspector window, adjust the frame size of the XDCam files to 1920x1080 and the pixel aspect ratio to square? When I create my new ProRes (1920x1280) timeline with these new clips, nothing would have to be rendered at output.

I'm looking for the best picture quality. Thanks for any thoughts or input.

Ray Ellis
Director
Footpath Pictures
Raleigh NC


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