That's the way I heard it, too, now that I think about it- HDCam leveraged existing Digibeta tech to get HD tape systems out quickly. Wasn't the FCC going to 'turn on' HD years earlier, then pushed the deadline? And, yes, other manufacturers use it. And, the signal is different, too. So we're all right. (Except maybe me... Perhaps 'bandwidth' is a poor explanation. Recording HD using per-existing tech makes more sense, pragmatically.)
________________________
Greg Huson
Secret Headquarters, Inc
Greg (at) SecretHQ.com
www.SecretHQ.com
DigitalServicsStation.com
On Jul 4, 2012, at 8:49 AM, "Terence Curren" <tcurren@aol.com> wrote:
> As I heard it from someone who was involved at the time, Sony came up with Psf so they could continue using their existing tape machine infrastructure. It allowed them to continue recording two "fields" of data the same way on tape. It was a progressive capture, that was then ripped in half into two fields.
>
> When they approached SMPTE with the spec, folks went nuts saying "we need progressive, not interlaced". And Sony's response was that they couldn't afford to retool their whole line to do that. So they renamed "fields" as "segmented frames" (the same thing) and added "progressive" to show they were captured at the same point in time.
>
> The reason it has continued into the digital non linear world is that it still needs to be made Psf to go to tape. So Avid and others had to support that workflow. Some day, when tape is gone, the Psf legacy will slowly fade away. (along with dependable archiving)
>
> --- In Avid-L2@yahoogroups.com, "johnrobmoore" <bigfish@...> wrote:
> >
> > Psf isn't really a "cheat" in my book but that's not important. I really don't see it as a way to keep bandwidth down at all. It's just a way to divide the progressive frame into two Psf's as if it were an interlaced signal only in this case the two "fields" come from the same moment in time. Also it isn't just a Sony thing. Panasonic DVCPro HD does it too. I'm not sure about D-5 but I think it's Psf too when dealing with progressive signals.
> >
> > --- In Avid-L2@yahoogroups.com, <Greg@> wrote:
> > >
> > >
> > > PSF is 'progressive - segmented - frame.' FPS is 'frames-per-second.'
> > > How the data is recorded is irrelevant, psf is only a matter of how the
> > > data is moved, really. (PSF is a cheat from Sony - a progressive frame
> > > is separated into two time-identical fields delivered sequentially to
> > > keep bandwidth down - then cached and re-assembled, essentially, as a
> > > progressive frame. (My non-technical understanding.) So, here, PSF is
> > > not the issue. P or I might be the issue.
> > >
> > >
> > > Assuming you're v5 or later, MC will handle the conversion from 25 to
> > > 23.98 more-or-less automatically. If you're capturing the 25 from tape,
> > > you'll need to do that in a 25 project, then open that capture bin in
> > > your 23.98 project. If your choice is 25i (aka50i) or 25p, I'd go with
> > > p, personally, because you're cutting it into a 23.98p project (there is
> > > no 23.98i) and they'll mix better However, if your deliverable is
> > > 5994i, you might consider cutting in that format, especially if the
> > > source ends up as 50i.
> > >
> > >
> > > The exception would be if you get quicktime, and the source is 25p. I
> > > like to simply 'slow down' the 25p by forcing it to import (or AMA) at
> > > 23.98 (you can batch conform the QT using cinema tools - that's the
> > > easiest way.) That integrates pretty seamlessly into 23.98. The
> > > picture is playing 4.1% slower, so keep that in mind.
> > >
> > > Hope that's a little help.
> > >
> > > gh
> > > -------------------------------------
> > > Greg Huson
> > > Chief
> > > Greg (at) SecretHQ.com
> > > www.SecretHQ.com
> > > DigitalServiceStation.com
> > >
> > >
> > >
> > >
> > >
> > > -------- Original Message --------
> > > Subject: Re: [Avid-L2] PAL question
> > > From: Jeff Hedberg <jeff@>
> > > Date: Tue, July 03, 2012 9:29 am
> > > To: Avid-L2@yahoogroups.com
> > >
> > > 'fps' and not 'psf'?
> > >
> > > Thank you.
> > > Jeff
> > >
> > > ------------------
> > > Jeff Hedberg
> > > Union Editorial
> > > 575 Broadway
> > > 6th floor
> > > New York, NY 10012
> > >
> > >
> > > On Jul 3, 2012, at 12:18 PM, David Ross wrote:
> > >
> > > > 25 fps.
> > > >
> > > > D.
> > > >
> > > > On 3 July 2012 17:02, Jeff Hedberg <jeff@> wrote:
> > > > >
> > > > >
> > > > >
> > > > > Hi,
> > > > > Usually I request my dailies at 23.98 pfs because we rough cut and finish at 23.98 and then turn the final master to 59.94 for broadcast.
> > > > >
> > > > > However, I've got a production company shooting overseas at 25 - and want to make sure I request my dailies properly.
> > > > > Would I refer to the frame rate as 25 pfs also? Or would I say 25P? (I'm pretty sure you all don't have to deal with anything like the 24 vs. 23.98 that we do here - but I don't want to mess up)
> > > > >
> > > > > Thanks,
> > > > > Jeff
> > > > >
> > > > > ------------------
> > > > > Jeff Hedberg
> > > > > Union Editorial
> > > > > 575 Broadway
> > > > > 6th floor
> > > > > New York, NY 10012
> > > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Search the official Complete Avid-L archives at:
> > > http://archives.bengrosser.com/avid/
> > > Yahoo! Groups Links
> > >
> >
>
>
[Non-text portions of this message have been removed]
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