Re: Cineframe 30/Cineframe 25 resolution loss vs. 60i

[James L. Arthurs] "Your assumption has been that the CF mode in NOT taking advantage of two fields in any way, but is just a single field, correct? If so, it would have a potential vertical resolution of 540 true lines (not 575).
I measured 575 lines. However, I believe that it's close enough to the "margin of error" that 540 may be the actual correct number, which would be one raw field. However, that's assuming a field that's unprocessed/blended/flicker-reduced, which doesn't happen when shooting 60i. In 60i, you get about 775 lines of resolution, which is close enough to Steve Mullen's theorizing about it delivering a max. of 820 lines that I figure it's within the margin of error as well, and just round it off to 400 lines per field.

If you shoot 60i, then separate into fields, lift the second field up one scan line and play out the sequence as individual frames then you have a slow-mo stream of images 1/60th sec apart with 540 true vertical scan lines each (not 400). "
Well, no. If shooting interlaced gave you 540 lines per field, then you'd be correct, but if you read Steve's article you'll see that you only really get somewhere around 390 to 410 lines per field (because of blending/blurring done to reduce interlace flicker).

So what I'm saying is, CF25 is BETTER than shooting 50i and de-interlacing, because 50i->de-interlace will give you about 400 lines of resolution, whereas shooting CF25 gives what appear to be 540 to 575 lines. My GUESS is that how they're accomplishing it is by giving us just one raw unblended/unprocessed field, simply because the observed 575 is so close to the theoretical 540 that it just seems likely. However, we don't know for sure how Sony is delivering CF25. It just seems reasonable to say that it'd be a single field. But that single field is higher-res than a de-interlaced field from the 60i stream would be.



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