Shoot 25p, export to 1080?
 

Ok guys. A simple question but no conclusive answer that I can find. If I shoot 25fps with the XH-A1, the captured native image is 1440 X 1080. However, it has been suggested that I may be able to produce footage from this and render at 1920 X 1080, albeit a "stretched" version. I always believed that 1280 X 720 was the only real option for HDV shot in progressive. and INTERLACED, (ie: 50i here in Pal Land), is the only means of obtaining 1080. In other words, 10801 is the only option. Can someone clarify or advise?
Best wishes,
Spud

Hi Mike. The first HDV cameras were either 720p or 1080i, but later models offered 1080p as well. Of course you can render out your 1080 footage as full HD. Obviously the horizontal resolution of the footage is 1440 not 1920, but the XH-A1 image is still pretty sharp even after upscaling.

Richard

Many thanks, Richard. I can do this, even if I shoot PROGRESSIVE? 25f mode?. I thought my options had to be 1280 for progressive, and 1080 (i) for intelaced footage only.

1080 HDV is always recorded at 1440x1080, regardless of whether it's if it's progressive or interlaced.

You have the full 1080 lines vertically (in fact, when shooting progressive you get a little more detail than interlaced). You only need to change a single dimension to get the correct aspect ratio - either invent more pixels horizontally or get rid of some both vertically and horizontally. In this case, it's better to interpolate out sideways than remove detail that is already there.

If only a single dimension needs changing (for whatever reason), it's better to upsize it than downsize the other.

And you can render out at any resolution you like. You could upsize to 28k if you wanted, it would be pointless, but there's nothing stopping you.

I think what you actually have is 1440x1080 at 1.333 anamorphic pixels, which equates to 1920x1080 square pixels.

So, yes, I guess you can export to 1920x1080.

I did a project in 25p last week, shot in hdv and edited in hdv. Then I export for dvd in Premiere cs3 using the "mpeg2 dvd pal progressive widescreen high quality" preset and I export one file using the "mpeg2 HDTV 1080p 25 high quality" preset.

This last preset does have frame width pixel set at 1920 but I change the "level" from "high" to "high 1440" meaning the width changes to 1440x1080 as it should.

I tested exporting to 1920x1080 and exported a framegrab, did the same for a 1440x1080 file and compared in photoshop, there was no difference at all between both in quality.

The only big difference was in render time which took a lot longer rendering to 1920x1080.

The workflow I use for progressive gives me very good results on crt and lcd tv's, something that I cannot say about interlaced material which gives worse results on a HD lcd caused by the interlacing.

Jamie, very many thanks for your help.
Spud

Mike, not sure if you are on Mac or PC - on Mac, MPEG Streamclip will batch this up nicely for you. I'm sure there is a PC equivalent too.

Nick.