Newsgroup: it.media.video.produzione
Titolo: (Inglese e Lungo) Suggerimenti x DV

Segnalo degli interessanti suggerimenti per l'uso di materiale DV:
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DV Stuff:
Recovering from DV mistracking errors:
Occasionally you'll get a tape that
won't play back properly, showing blocking or checkerboarding in bands
across the picture and/or towards one edge of the picture. I've now seen
several tapes that won't play back properly in this way, including one that
wouldn't play back correctly in either the Canon XL1 that recorded it nor in
a DVCPRO VTR. I've found that most Sony gear will do a pretty good job where
other manufacturers have a hard time with such tapes. However, when the
really badly mistracked stuff won't play back properly in just any old Sony
machine, you can often recover the images in a VTR with Dynamic Motion
Control capabilities such as the DSR-1600, DSR-1800, or DSR-2000. These will
work with any DV25 tape: DV, DVCAM, or D-7. The DSR-2000 will even recover
mistracked LP DV tapes some of the time.
DVCAM tapes can be used in DV recorders and vice versa.
I used DVCAM tapes
in my DHR-1000 when I couldn't get DV tapes longer than 60 minutes in my
neck of the woods. To suss out what tape you need, take the DVCAM running
time and multiply by 1.5 (since DV uses a 10 micron track pitch to DVCAM's
15 microns). For example, a PDV-94ME runs for about 141 minutes when
recording DV. Likewise, I've run many a DV tape through a DVCAM camcorder
with no problems.
Recording DV unlocked audio via FireWire with the DSR-30 DVCAM VTR: Press
and hold down RECORD and PAUSE while turning on the power. The deck will
emit a sustained beep, at which point you can release the buttons. It will
now accept unlocked audio. It'll record 15-micron DVCAM still, but the audio
will be unlocked. This trick is also supposed to work with the DSR-200
camcorder. Note: the DSR-11, 20, 40, and other will record unlocked audio
without needing this trick. Late-model DSR-30s are also supposed to accept
"NS AUDIO" (nonstandard, i.e., unlocked) without too many conniptions.
Color bars on the DCR-VX1000 and DSR-200: Press and hold PHOTO and the
START/STOP red button while turning the camera section on. You'll get
full-field bars which you can record, along with any incoming microphone
audio. You'll have to turn the camera off to get rid of them. More recent
cameras, like the VX2000 and DSR-PD150, have colorbars selectable in the
menu.
Color bars on the Canon XL-1: Turn on the camera to the fully auto mode
(green square).  Then press both the shutter speed buttons simultaneously
for a few seconds, and full-field bars will appear. Pressing both buttons
again for another few seconds turns them off (a definite improvement over
the Sony).
Playing DV or DVCAM on DVCPRO VTRs: First, make sure your machine is
up-to-date: VTRs made before June 1997 need an eprom upgrade to play DVCAM.
Check the serial number: it's of the form MYxxxxxxx, where M is a month
letter, A-L, and Y is the last digit in the year. F7xxxxxxx means the
machine was built in June 1997, and it's OK. H6xxxxxxx would mean the
machine was born in August of 1996 and the EPROM upgrade is required.
Second -- and this is very important -- use the setup menus to specify DV or
DVCAM before you insert the tape! The playback mode "locks in" when the tape
is inserted, so if you set DV or DVCAM mode after loading the tape playback
will still be attempted as if the tape were a DVCPRO tape, and you'll get
really crappy results.
Line inputs on the VX1000 (or other consumer cams)? You can fake it: first
you'll need a 3.5mm dual-mono-to-single-stereo Y Adapter, Radio Shack Cat.
No. 274-375B; this'll give you right and left channel mic inputs on separate
mono jacks. Use an Attenuating Audio Cable with an RCA plug on the line end
and a 3.5mm miniplug on the mic side: Radio Shack Cat. No. 42-2461A. Sony
also makes a stereo pair version of this; if you just need one, peel the two
cables apart. You can now jack into line-level audio sources. With a bit of
luck, you can even plug a line source into one side, and a mono mic into the
other -- and the levels might even match up... If you follow this route, be
sure to gaffer tape the cables out of the way so that they don't get pulled
or wiggled during the shoot, and avoid touching or moving the $%#@&!
delicate miniplugs. Also, only use battery power when recording via these
jacks lest any residual power-supply ripple or ground loops cause
intolerable AC hum problems.
Using monophonic mics on cameras like the VX1000: the mic input on the
VX1000 and most similar cameras is a standard 3.5mm stereo minijack. If you
plug in a mono mic, you'll only get one channel of audio. Use a
mono-to-stereo adapter available from Radio Shack to fix this: part #
274-374. Or, use a 3.5mm dual-mono-to-single-stereo Y Adapter, Radio Shack
Cat. No. 274-375B to give you separate mono right and left channel inputs
for two mics.
Line/Mic adapter boxes and cables: if you don't want to mix 'n' match cables
as described above, both Beachtek and Studio1 make very nice adapter boxes
allowing switchable line/mic inputs and the use of XLR cables with many of
the small consumer cameras. Equipment Emporium and Calrad both carry premade
XLR-mini adapter cables of various sorts, many designed specifically for
solving these sorts of connection problems.
Those Canon IF lenses on the DSR-500WS and possibly the DSR-300 are so
pleasant to use and make such nice pix -- if you can avoid bumping the %$#@*
macro button! The 18x on the DSR-500, at least, has a large and
easily-pressed macro ring lock button located on the left side of the lens.
Older Canon lenses had a lock button you had to pull up on to move the macro
ring; it was virtually impossible to bump the lens into macro mode
accidentally. The new lenses have a push-to-unlock button with such a light
touch that accidental macro shots are almost impossible to avoid. On two
occasions now I've managed to just brush against it while groping for other
lens controls or when moving the tripod to a new setup, bumping the button
and turning the ring just enough to screw up focus but not enough to be
readily visible in the finder... I suggest gaffer-taping the macro ring in
place so it doesn't get moved accidentally.
Mixing different brands of tape: In DV's early days, Sony and Panasonic
tapes used different lubricants, and if you used one brand a lot and then
switched to the other, incompatibilities between the lubricants (which get
deposited on heads and tape guides) could cause VTRs to jam up. Supposedly
this was fixed in 1997, but I hear that people are still having problems of
this sort in September 1999 (I have no more recent reports that would lead
me to believe that the problem persists OR that the problem is solved!).
This is not a DV/DVCAM vs. DVCPRO problem; while many of the people
reporting the jams are inserting the occasional DV tape into a DVCPRO
transport, many others are seeing the problem in consumer DV equipment,
which can't play back DVCPRO to begin with.
Anecdotal evidence would seem to indicate that the biggest problems occur
when one brand of tape is used exclusively for a long time, and then the
other brand's tape is used: instant jam! If one switches back and forth
between the different tape brands frequently, say, switching between Sony
and Panasonic every three or four tapes, the problems don't seem to appear.
It may be that frequent switching prevents a critical mass of one lubricant
building up in the transport; switching tapes may clean off accumulations
before they get heavy enough to cause problems. Whether this is really a
solution, or if frequent switching only leads to a long-term buildup of
cross-contamination pollution on the tapes themselves, is unknown.
I run 75-80% Panasonic DV tapes in my gear, with the remainder being Sony DV
or DVCAM; I've never had any hint of a problem over four years. It's rare
that I run more than four hours on one brand before using the other brand of
tape, so that may be a good starting place as to what a safe interchange
frequency may be.
Thus there would appear to be two general approaches to this problem. One is
to pick one brand of tape, and "stick" with it (sorry about the pun!). You
simply won't see the problem. The other is to interchange tape brands
frequently, so the gunk from one never builds up a critical mass inside the
transport to jam up the other tape when it's inserted.
Problems with tape interchange of this sort may be reduced by using a tape
cleaner in between the different tapes.
Your results may vary: and if you've had any positive or negative
experiences of this sort, I'd like to hear your story...
DPS Spark problems: Vynny Ward compiled an excellent help page which is now
posted here.
Betacam:
NEVER stuff a Betacam tape into a UVW-series VTR without checking to see if
there's already a tape inserted. The tape will go in just about all the way
on top of the existing tape; it'll then jam in place. UVWs do nothing to
prevent this! Fortunately, unless you've really rammed it in
enthusiastically, you can usually pry it out, and usually without any
permanent damage occurring...

 Segnalo degli interessanti suggerimenti per l'uso di materiale DV:
[mega cut]
Grazie Silvio, mi pareva di aver letto qualcosa sull'utilizzo di
cassette miniDV di marche diverse!
Anche se non ho capito proprio tutto, se vuoi puoi postare il link?
Grazie e saluti
Fabio
--
indirizzo alterato, sostituire invalid con it

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c'č un sacco di altra buona roba.
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