Philip Younger
September 19th, 2009, 10:41 AM
First apologies if this should be in the editing section but thought I would start here as my question is XH-G1 specific.
I've not use Vegas pro before and slightly confused about the best capture method. I am just reading the manual right now and it states that I first have to decide whether to capture as DV or HDV/SD then in another section I have to select the resolution. I assume I select HDV/SD.
Then, note I'm in PAL land filming in HD 1080i, do I capture in 1440x1080 or 1920x1080 x50i I find this rather confusing as the Canon manual (from memory) seems to suggest both resolutions
Richard Hunter
September 19th, 2009, 08:19 PM
Hi Philip. This doesn't sound like a G1 specific problem, it applies for any HDV camera. So you would probably get more and better answers in the correct forum.
The camera can shoot in HDV or SD resolutions. If you shoot SD then you would capture as SD (DV format).
If you shoot HDV, you have a choice of capturing native HDV (1440x1080) or downsizing in cam during capture to SD DV format.
I don't think Vegas can capture HDV as 1920x1080, but even if it could there's not much point doing it unless you already have mostly 1920x1080 footage in your project. If you stay with 1440x1080 you are basically just transferring the video data from tape to hard disk, without any conversion process.
However, if you plan to do a lot of editing and applying filters/effects to the video, it might be worthwhile capturing to an intermediate codec such as Cineform. This creates huge files, but the advantage is that the files will playback easier on your PC, and since they have increased colourspace, you should get less degradation when you apply the filters. (If you're happy with your system performance with HDV and the quality you get from it, then there's no need to buy Cineform.)
Richard
Philip Younger
September 20th, 2009, 05:42 PM
Thanks Richard, I am continually confused by this 1440 that Canon quotes along with 1920 - which is it, if I have this correct in my mind it is actually 1440 but in someway compatible with 1920.
BTW Vegas 9.0b states it does capture 1920
Richard Hunter
September 20th, 2009, 08:19 PM
Hi Philip. HD pictures are all 16:9 aspect ratio, usually meaning 1920x1080 or 1280x720. The HDV resolution is 1440x1080 which does not seem to fit. But if you look at the properties of an HDV clip in Vegas, it will show the pixel aspect ratio as 1.333. So what happens is that the editing programme stretches out the image to fit the 16:9 frame aspect ratio.
Yes Vegas can capture 1920x1080, but that only applies when the source is 1920x1080. For HDV sources, you should use 1440x1080.
Richard
Philip Younger
September 21st, 2009, 05:11 PM
So, if the 1440 is being stretched to fill the 1920 aspect am I correct in assuming then that what we view on screen is a distortion (streched view) of the correct, true image?
Richard Hunter
September 23rd, 2009, 06:23 AM
Not really. A better way to look at it is that the "correct true image" that the camera sees is squashed down to fit the 1440 horizontal pixels during recording. Then when you play back, it has to be stretched back to 1920 pixels on the monitor in order to look correct again.
Richard
Philip Younger
September 24th, 2009, 05:15 PM
So is that a kind of compression? why would Canon decide to build a camera that squashes the image down only to have it strehced back up again when played back? Why not just let it shoot / capture the image at 1920? very confusing!
Richard Hunter
September 24th, 2009, 08:02 PM
Hi Philip. It's a reduction in resolution rather than compression, and it is presumably due to sensor technology limitations at the time that the HDV standard was developed. Note that it is not only Canon cams that do this, any HDV cam that shoots 1080 has to have 1440 as the horizontal resolution. Some pro video standards also use 1440x 1080.
And like many other things, it is only confusing until you know how! :)
Richard