It is not that encoding at a lower resolution is a bad thing, as very few the of the sub-$10k HD cameras can resolve close to their recorded image size anyway, but the non-standard size makes post more difficult. So CineForm added scaling features within HDLink to resize "non-standard" footage to standard frame sizes. The added benefit of this is it simplifies the mixing of HVX footage with HDV/HD footage. Remember, CineForm products don't have the "baggage" of being a native editor, so you can freely mix footage from any source.

For 960x720 (source) footage from the HVX200 we suggest up-scaling during conversion to 1280x720 - the result gives you a standard HD picture resolution that matches expected distribution formats (no formats distribute at 960x720). Although the up-scale doesn't gain in detail it doesn't lose detail either. During post all your additional elements - graphics, effects, titles, etc. - can benefit from the additional 33% image resolution, making your final broadcast, HD-DVD, BluRay, or film-out master the best it can be. In contrast, you lose this advantage using native editing because of its limited 960x720 source format.)

For 1280x1080 (source) interlaced footage, we recommend up-scaling to 1440x1080i for Aspect HD and 1920x1080i for Prospect HD. Both 1440x1080 and 1920x1080 are standard distribution formats for MPEG2, VC-1, WMV-9, etc. Many of the first 1080 WM9 clips were 1440x1080 as most PCs couldn't play 1920 clips (machines are faster now, so it is less of an issue.) Again, posting in your output resolution rather than source resolution delivers the best results.

For 1280x1080 (source) progressive footage, we recommend downscaling to 1280 x 720.  Why would we recommending scaling down rather than up? Of course you can scale up to get the most of your titles and effects elements, but there are diminishing returns. As an example, an SD project edited at 1920x1080 still looks like SD - you have to have a lot of effects and titling elements to obscure you SD image. Despite the advances in scaling algorithms, image detail can't be increased (only perceived sharpness is enhanced with good scalers.) You are probably thinking, "this is not SD...if you scale a 1280x1080 to 1280x720 aren't you losing resolution"? Not if the source footage contains less detail than the target 720p image, as it does with the HXV200. Here's the explanation...the camera uses three image sensors, each of which is only 960x540. Due to its "pixel shifting" algorithms the camera will resolve a little more than the sensor size would suggest, about 30% more in each direction (although testing shows slightly less than this). But if we nonetheless use the 30% estimate above the three 960x540 sensors, the "effective" resolution after pixel shifting yields a 1248 x 702 image (pretty close to standard 1280x720.)  Up-scaling this further to 1080p doesn't gain any detail, it just uses more disk space.

Is the source Image A or Image B? (Each image is about 720KB)

To prove that 1280x720 sufficiently contains all the detail from the 1080p modes of the HVX200, we have provided this test example (thanks Mike for this source). Although not a glamorous scene (no reflection on Mike's artistic expertise we're told...), shot though a window into a bunch of trees, this 1080p24 clip is perfect for this demo because it is filled with high-frequency details. The source image was converted to an AVI twice, once from its source resolution of 1280x1080 after it was scaled down to 1280x720 (during conversion with HDLink, then again as it was up-res'd back to 1080 - using VirtualDub's "resize" with the "Lanczos3" Filter mode). The fact that it is nearly impossible to visually differentiate between the two clips is proof that the original scene contains detail less than 720p. Can you tell which image was scaled? Please try this with your own footage. (Note: make sure your browser doesn't scale the image. These files were originally 1280x1080 PNG files, but we did a very light JPG compression on them to reduce file size).

In general we recommend shooting in the HVX's 1080p mode as it does resolve a little more horizontally than than 720p (960x720) mode can store. In addition, the 1080p mode is significantly less compressed. Why? DCT compression (like DVCPRO-HD) has trouble with excessive detail (as DV shows with its mosquito noise, plus blocking in shadow details), so storing 1248x702 worth of detail in 1080p24's 80Mb/s is much cleaner than 720p24 40Mb/s. So shooting 1080p is a good way to reduce artifacts. In the end we recommend the 1080p-to-720p down-res when converting with HDLink, as the workflow enhancements of more efficient disk usage, higher editing performance with more real-time operations and square pixel processing, will out-weigh the gains of a 1280x1080 (or 1440 or 1920) timeline.

(Answer to the question above....Image A was scaled twice.)

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