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| A DV(L)-FAQ [e] |  |
DVL-Digest 517 - Postings:
Index
35mm vs. HDTV
Consumer cameras
End of DV?
FCP-RT
GL1
Matrox RT2000 vs. Pinnacle DV5
predictions about Apple (Astar
SV: Sony DVCAM Tape question//
35mm vs. HDTV - Adam Wilt
> As a professional DP that is also my main objection to HDTV. When
> Sony and Ikegami and Phillips claim that HDTV "looks just like 35mm"
> I say bullkaka. The much smaller chips answer to different optical
> laws...
To get comparable depth of field on the 2/3" HD cams requires opening the lens
about a stop and a third (if I remember correctly). It's only a problem when
you want the very shallow DOF that requires the lenses to be more open than
they can be.
Of course, if the lenses have a sweet spot at f4 or F5.6, but the DOF you want
is at F2.8 in HD, you've got the tradeoff to make.
> also because those 3-chip cameras have a great distance between
> the target area and the back of the lens due to the large color
> dividing prisms. Therefore, normal lenses for motion picture cameras
> do not fit on the HDTV's. Some progress is made by Panavision who
> built special lenses for the HDTV.
That's really a nonissue. The deeper flange-back required by the prism simply
limits how far back the lens can protrude; it means the designer must use
retrofocal designs at longer focal lengths instead of just at wide angles. The
same issue occurs to a lesser extent with any through-the-lens viewfinding
film camera; lenses to fit an Arri with mirror shutter must remain clear of
the shutter, while the old Mitchells using rackover for TTL viewfinding
allowed lens elements to almost touch the film plane. A 20mm can be a "simple"
design on the Mitchell, but it needs to be retrofocal on the Arri (I may be
off by a few mm, but the concept is the same).
The old tube-based Panacams used relay lenses to allow fitting 35mm primes
(which both solved flange-back problems and also rescaled the image for 2/3"
tubes, allowing use of 35mm angles with 35mm DOF at given f-stops).
"Unfortunately" the 2/3" HD sensors are so sharp that the abberrations induced
by a relay lens were unacceptable, hence Panavision's Primo Digital series
designed expressly to work with 2/3" CCDs on prism blocks.
Cheers,
Adam Wilt
Consumer cameras - "Perry"
We were talking about the relative image quality of pixel counts. I've just
done a shoot in a church with 4 cameras:
JVC GY-DV500
Sony VX-1000
Sony VX-9000
Sony Betacam recording to DHR-1000 via composite.
The 'feature' that lets the two consumer cameras down is the lack of any
information in the blacks. It is probably the result of excessive 'noise
coring' and incorrect gamma. I'm about to get a PD-150 for a review and I
will be very disappointed if it is not substantially better in this area.
Perry Mitchell
Video Facilities
http://www.perrybits.co.uk/
End of DV? - Adam Wilt
> >> Hitachi to Release World's First 4.7GB DVD-RAM-Standard Compliant DVD
> > Perhaps Sony's BetaSX (which uses MPEG) could morph from videocassette
> > to DVD, but BetaSX is high-end ENG and not designed or intended for
> > production....
Its 18 Mb/sec data rate is a bit high for DVD, and its multigeneration
performance is worse than DV's.
> Now if you could shoot on a Sony camera that records
> to a 13GB 2.5" notebook harddrive in a removable
> docking bay in IBP MPEG2 MP@ML format, then you
> can take that drive chassis out of the Sony camcorder
> and stick it in a Pinnacle DC2000 NLE, you don't have to
> waste any time with transferring, and you can then
> edit in native IBP MPEG2 format and output with no
> further rendering direct to your videotape or
> DVD master.
Hmm, both JVC and Panasonic are working on 2.5" hard disk based DV camcorders,
and Ikegami has been selling disk-based camcorders using Avid compression for
several years. Pop the disks out and put 'em into an Avid docking bay, and
you're good to go. Not cost effective for most, but very popular in certain
niche markets, like law enforcement (mostly due to the continuous record
capability with "save last ten seconds" functionality).
On the more cost effective side there's the Sony MD Discam, recording long-GOP
MPEG-2 at either 8 or 4 Mbps on minidisc. The 8 Mbps images are pretty
tolerable. The 4 Mbps pix are, well, impressionistic if there's any motion!
And while you might be able to edit IBP MP@ML with the DC2000/DVD2000, what
will it look like? What will the image quality be in the 15 or so frames on
either side of an edit, especially one where the two stream's GOPs are out of
sync and the target GOP must be severely reworked? At DVD-compliant data rates
(9.8 Mbps max), what will the quality of an edited stream be, hmm? I see all
sorts of crap fly past on DVD -- even those with human compressionists in the
loop (granted, the average data rate is 3.5 Mbps). And that's with one
compression. You WILL decompress and recompress the GOP containing an edit
(even a cut) unless you stick to I frames in both streams. And we thought
color-frames (especially in PAL) were bad! The visual losses will likely range
from minimal to noticeable.
Me, I'll stick with the more predictable and (for now) higher-quality DV
compression, or the IPPP GOP-4 MPEG-2 compression on the DC1000/DVD1000 and
also available on the 2000 lineup. While you CAN edit distribution-quality
MP@ML with enough buffering, that doesn't mean you WANT to -- at least if you
care about image quality.
I am happy to be proven wrong on this. Anybody wanna make me happy?
Cheers,
Adam "still on DV-L, not yet on MP@ML-L!" Wilt
FCP-RT - Adam Wilt
> << will FCP-RT even be available >>
>
> I wonder about this as I have heard zippo about a FCP RT version,
> anyone care to spout off?
It was announced at NAB, concurrent with the Matrox RT-Mac board. FCP RT is
due "in the fall" sometime (I don't put much faith in ship dates that far out,
grin) along with the RT-Mac and the ProMax RT-MAX boards.
And isn't zippo a registered trademark of the Ronson lighter company? :-)
Cheers,
Adam "still in the dark ages for FCP 1.2.1" Wilt
GL1 - Adam Wilt
> Why did the colours look best when I was test shooting inside the store
> (fluorescent lights) and the white balance was on the outdoor preset
> (sunshine symbol)? The preset for indoor lights (lightbulb) looked the
> worst - blue and washed out.
The daylight setting (5600 K or so) better matched the color balance under the
fluorescents (discontinuous, but sorta somewhere between 5000 K and 10,000 K).
The indoor setting (3200 K) is for use under yellowish incandescents.
> Why does the picture seem to have a strobe effect when in movie mode?
It's 30 frames per second, instead of 60 fields -- half the temporal update
rate.
> Does it play back like this?
yes.
> Does the different recording speed of movie-mode affect editing in any way?
Only in that you'll want to render effects and transitions on a frame basis
instead of a field basis for best effect.
> If some is shot in normal and other in movie-mode, can they be edited
> together?
Yes.
> Is there a way to do manual zooms, like the MTV-style technique where you
> seem to be far away from the subject, then really close up in 1 second?
Not really. But have you thought of the tried and true technique of
slingshot/bungie-cam? ;-)
> Can anything be done to work with the fact that the sound recording cannot
> be manually controlled? (i.e. so external add-on device?)
Apparently the ACG is more of a peak limiter than an auto-leveler, so using a
mixer or XLR box will allow you to set levels and attenuate things.
> Finally, what is this Canon Owners' Club suggested on this list?
Check out Chris Hurd's XL1 Watchdog at http://www.mediadesign.net/canondv.htm
and see if he has details or links. Also have a look at Canon's website.
Cheers,
Adam Wilt
Matrox RT2000 vs. Pinnacle DV5 - Adam Wilt
> TO: Ken Bell,
>
> Hi Ken,
>
> I saw an interesting post you made a while back about your company's
> experieces with the boards.
>
> Could you email me an update....
Ken, if you'd feel comfortable posting to the list, I know I'd appreciate
hearing the details, too. As would a bunch of other folks, I'm sure.
> I would also like your thoughts as to why a videographer should purchase a
> system from a turn key business like yours rather then buying the
> components separately and doing a self install.
I'm not Ken, nor do I play him on TV. But I have put together five or so NLEs
myself.
The big reasons to go with a VAR are time and security:
1) The time you are likely to spend getting everything installed and REALLY
working (not just installed, but all the weird incompatibilities, AGP aperture
settings, IRQ priorities, APM settings, etc. taken care of) will more than
offset the added cost of paying the VAR to deliver you a known working,
debugged system.
2) If/when something goes wrong, the VAR is there to make good on it: the VAR
builds those systems all day long, and has enough experience with each setup
to be able to pinpoint problems quickly. Also, you won't get into a pissing
match between board and software vendors where each one points at the other as
the source of the problem.
If you like fiddling with computers' innards, and have the leisure time to do
so, fine. But if you're on a deadline, and/or you're in business to make
video, not play computer integrator, then paying Ken or Charles or Alexei or
Jeff or Richard or Robert or any other the other VARs on this list (or off it)
to do the scut work makes a whole lot of sense.
Cheers,
Adam Wilt
predictions about Apple (Astar - Adam Wilt
> > I'm still waiting for some reaction to this bombshell, but I haven't
> > seen anything come across. Passing strange, no?
> I agree. A strange and probably significant lack of reaction.
> Me too. Or ???
Or maybe it's something that doesn't really lend itself to discussion. Apple
does not comment about unannounced products. There's nothing about this on
AppleInsider, either. So it's pure speculation along the lines of "how many
angles can dance on the head of a pin? OK, now how many MPEG-2-compressed
angels can dance on the head of a pin?"
Apple sometimes works in a linear way but can (and often does) suddenly
reverse direction (clones, Newton, Rhapsody...). It's fruitless to
second-guess them. But hey:
"I like to watch."
-Chauncey Gardner, "Being There"
Adam "but I like to shoot, more" Wilt
SV: Sony DVCAM Tape question// - "Perry"
Fredrik posted:
>As far as i know there´s only two tape manufactures making DV-tape, Sony
and Panasonic. All ohter manufactures are bying tape from them and spool
them onto their own boxes. <
Whilst this was true a couple of years ago, I am sure there are other
manufacturers with an evaporation plant by now?
Perry Mitchell
Video Facilities
http://www.perrybits.co.uk/
(diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-)
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