The Definitive Answer, Once and For ALL!
 

Does post letterboxing 4 X 3 video in PPro 1.5 degrade the picture? If so, how?

If you mean adding a black mask top and bottom to blank out 25% of the screen image then no, this won't alter the resolution, brightness, sharpness, contrast, gamma you name it. A face in the middle of the screen is as sharp whether it's masked or not.

If however you show this full screen on a 16:9 TV, then the 430 (PAL) lines you have left after masking will be interpolated to fill the 576 lines of the TV, and this does indeed make the image a lot softer.

tom.

If working with DV footage, then yes it will degrade the quality, in the sense that the DV stream needs to be recompressed. But one generation of DV recompression is nothing to be worried about. If you are already adding effects to you video (color correction or else), then a recompression was already required.

However, if you do this in 2 passes (color correction then render [export] to DV, then letterboxing and the final render [export] to DV), you'll have 2 generation losses. It would be better to do it all in one pass, or render [export] the color-corrected video to uncompressed video. But then again, DV can go through a few generations with very little artifacting.

So then what you are saying is that on the timeline, have everything applied at once, i.e. lettrboxing, color correction, effects (no pre-rendering before the various effects) and render only once to then export to DVD?

It is OK to render along the way. The program will rerender as needed from the original information, not from the preview files that already exist.

Just don't export to a new AVI and then letterbox that AVI. That would add another generation of loss.

Thanks. Master Steve. By the way, is what J.F. Robichaud said true? (I'm not trying to start a skirmish, I'm only trying to know what's what! Thanks!)

He is correct, except that I object the way he uses the word "render". He is correct, except that it is safer to use the word "export" instead of render. I had to read his comments again to agree with him. The first time they sounded wrong because to me, rendering is creating preview files. The way he used it, I believe, was to export to a new AVI and then work on that again.

Render is a difficult word to use with new editors since Premiere Pro uses it specifically to mean creating preview files. Yet older editors use render to mean export. Sometimes. Sigh.

Just leave it that he is correct, and understand exactly what he means by render.

Yeah, when I said render I meant exporting to a video file. I should have been clearer.

In other words, you can edit in one sequence, add colour-correcting effects, nest that first sequence in another one if you want and then do the letterboxing (either a crop or adding a "black bars" matte). When you export that, all the effects will be computed starting with the original source files, so it's only one generation of loss.

Thank you. But you mention one generation loss. So that means by adding the black bars from the title designer I am degrading the image somewhat? Just by the use of the matte bars (as opposed to the pillar bars, LOL)

When you add a title, or any effect, or anything except a simple straight cut, the video has to be recompressed. So yes, just adding bars reduces the quality ever so slightly.

Thank you! I guess this even affects the big Hollywood boys when they shoot in HD.

I suppose they suffer a bit, but they spend a lot more time manually compressing sections of their films or HD video to get it down to the SD that you see on a DVD. They don't just run it through some software a couple of passes on the entire video. It is much more complicated than that.

Besides, they start with a much higher quality and therefore can afford a bit of loss without detection.

Yeah, the lucky bastards.

You could render out un-compressed, depending on the length of the project, the size of your hard drive, and your computer specs. I do this all the time at work. You can also use quick-time animation compression, it will bring down the file size a bit, and it is lossless. But, I think that once you do that you may have to render the footage before you can view it in the preview window. I am usually going to after effects after rendering from premier.