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DVL-Digest 507 - Postings:
Index


DV tape life expectancy
Early tape recorders
Gaffer tape
Lights
MP-3
Premiere vs Speed Razor vs Edi
Zebra


DV tape life expectancy - Adam Wilt


> Does it seem conceivable that my DV tapes should begin to suffer from
> "stiction" after about a year and a half? I thought at first my tape
> playback problem was due to a worn or misaligned video head, but it turns
> out the tapes play badly on other DV machines as well. The older the tape,
> the worse the artifacts (portions of the picture lagging behind, timecode
> stopping every few seconds and then suddenly catching up.)
These sound like severe dropout problems, not stiction: yes, the pix stick,
due to the frame buffer, but the tape keeps on rollin'
> If I make a fresh recording over the seemingly faulty tapes, those newly
> recorded sections play back fine. Does that make sense?
Yes. It implies the existing recordings are going bad (due to different
tracking or alignment on the original recorder; dropout and shedding;
demagnetization; tape stretch or distortion; who knows?) but that the tape
itself is still usable. The question is, what happens if you try to play back
today's recordings in 18 months?
What are your storage conditions like?
Cheers,
Adam Wilt



Early tape recorders - "Perry"

>(among them three Marconi reel to reel audio tape
recorders which are still working and I think are among the first tape
recorders ever)<
Ooh boy, can't resist this one!! In the early '60s I worked in a UK Gov't
lab that had a Marconi MR-1, which was probably the first commercial tape
machine after the War in Europe (not sure how it would date re Ampex, both
were made in late '40s). It had a couple of enormous reel motors which sat
on the floor of the cabinet, with long extension spindles to the waist level
deck. The best story was the heads were on the outside of the tape path,
and required the operator to put a half turn in the tape on either side of
the heads! Tape in those days had a natural 'curl' and was wound on open
sided spools; if you tried to wind it 'inside out' it was liable to go off
like a volcano when in fast motion.
I don't recall how big the electronics bay was, it would have been vacuum
tubes (valves) of course. We also had some later MR-2s which had a
conventional tape path.
Interestingly, Britain's GEC company has resurrected the name 'Marconi' to
reposition itself as a major player for the Internet age. When I started in
the BBC in 1969, Marconi was still a major provider of TV and Radio
equipment. They made some good monochrome cameras, but never made a color
camera worth a bean. They battled on as a broadcast systems manufacturer
for some years, but concentrated on transmitters and military equipment.
In the early '80s I chanced upon a most amazing infra-red camera that
Marconi made that was newly released from the Top Secret List (they were
trying to sell it to the Police). It was based upon a mechanically scanned
image (using rotating prisms) onto a cooled single point sensor. This was
necessary to achieve a standard recordable television picture. This camera
could detect the thermal image left behind by a parked truck over a week
after it had moved on! I remember they showed a tape of a helicopter ride
made on a moonless night, and you could see the reflection of trees in the
surface of a lake as clear as daylight (just think about it). For me though
the most amazing thing about this camera was the lens which was made from
elements of solid Germanium! (Glass is opaque to true IR) The front
element was about 6inches diameter and for visible light it acted as a
mirror of course. I believe Marconi still make thermal imaging cameras for
use by rescue services, but they've got rather more portable!
Perry Mitchell
Video Facilities
http://
www.perrybits.co.uk/



Gaffer tape - "Perry"

>, a wonderful use for gaffer
> tape... Unreal Films field research has proven that ordinary
> gaffer tape is
> GREAT for preventing blisters on long tramps (hiking, rambling,
> bushwalking).
Here is the method of employment:
1) make yourself comfortable in your favourite chair
2) ensure you have a suitable selection of refreshments to hand
3) tape your legs to the chair
This method is guaranteed to prevent all above mentioned blisters! :)
Perry Mitchell
Video Facilities
http://
www.perrybits.co.uk/



Lights - "Perry"

In general it is always easier to start from scratch and provide all your
own lights. The true skills are integrating your lighting with the ambient
lighting in a real location to create a desired overall effect. It needs
some experience and a fair amount of kit to achieve this objective.
Usually it is very difficult to change the levels and color temperature of
ambient lighting, so it is always best when possible to use this lighting as
is, and then add your own lighting to match. To this end one of the most
valuable resources I possess is a couple of HMI daylight lamps. I managed
to find them for a good price second hand, but they have been worth their
weight in gold! They are pretty efficient so the 1200W gives considerably
more light than a 2K tungsten. This allows me to use daylight coming
through windows, and also allows me to diffuse the light without worrying
about the loss of lux. I have just finished shooting a church service, and I
don't know how I could have done this job without them.
The alternatives are to blue gel tungsten lights (which loses light) or to
put suitable filters on all the windows. The latter method is usually
preferred by broadcast and film professionals but is rarely affordable by us
shooters with more modest means. I once had to shoot a poor chap in Paris
and wanted to see the Eiffel Tower viewable out of his window. He was on
the 10th floor which made filtering the window almost impossible, and I
hadn't brought my HMIs on the trip. I needed about 5KWs worth of blue
gelled tungstens and we all near boiled in his modest office space!
Close shots are less of a problem because having a rim lit key or a back
light that is into the camera white clip is pretty accepted these days. If
you therefore color balance for a tungsten fill, you can use daylight
knowing that the clip will make it look white.
Perry Mitchell
Video Facilities
http://
www.perrybits.co.uk/



MP-3 - "Perry"

francesco schiavon posted:
>I'm not sure why you would want to use an MP3 on FCP. MP3s are very
compressed so their quality is really bad (for video editing).<
With all due respect Francesco, this is nonsense! I believe MP-3 can have
different quality settings, but I recently used it to receive a music file
via e-mail from a well known professional audio manufacturer and the quality
was fine. They wanted the specially composed piece to be included in a
video I was editing for them, and as far as I know the finished program has
been accepted with no reservations by professional audio 'ears'. It is
probably a similar argument as for MiniDisk where for most folk the quality
is fine. After all, the vast majority of video programs will be either
broadcast or heard via VHS and neither can sustain the very best audio
quality.
Perry Mitchell
Video Facilities
http://
www.perrybits.co.uk/



Premiere vs Speed Razor vs Edi - Adam Wilt


Hi, Tony!
> Unreal Films makes long-form documentaries, sometimes feature length. They
> are observational, so in editing we tend to have to wade through TONS of
> material, and cut through numerous versions until we get where we need to
> get... both me and my editor are experienced using Avids... We are now
> considering a replacement.... Here's the options we're considering at the
> moment:-
> 1. DV Raptor and Premiere
More stable, yes. But the lagginess in long-form is a known Premiere problem
that Raptor doesn't affect.
> 2. RT2000 and Premiere
Still Premiere. There may be a future version of certain other excellent
editors supported on this platform if rumors are to be believed (I'm not sure
if the plans are public, so I can't say more).
> 3. DV Raptor and Edit DV
Great for long form; fast even with many hours and thousands of cuts in the
timeline (DO claims slowdowns are detectable with 800 or so edits but no user
I've spoken to has seen this, even with 2000 edits in the show!). It's
operationally very fast but some things require a bit of manual intervention
(like moving filters around when rippling edits) and only one timeline per
project is allowed. It's a very stable system, too.
EditDV with DO's own hardware is also work a look.
> 4. DV Master Pro and Speed Razor
Older, yes, and the stability of SR gets mixed reviews... but I have no
personal experience to offer.
> 5. Avid Xpress DV, Edit* etc
Haven't worked with Xpress DV yet but it looks a nice way to go if you're
Avid-centric and need the media-sharing capabilities of Avid.
Edit* is rather nice but quite expensive. Doesn't it require DigiSuite-level
hardware?
Also consider Final Cut Pro on the Mac (if you can tolerate that "other"
platform). So far very stable (I've only had it lock up once, just last night)
and quite fast to edit with, though I find EditDV to be a bit faster for
assembly. Fine for long form with little if any slowdowns. Multiple sequences
within a project makes it easy to try out variations or to cut shows in
"chapters", something you won't get in EditDV.
All these NLEs have very different personalities, so I'd suggest getting
opinions but then sitting down with the top candidates and seeing if they work
the way your brain works. I tend to be technologically ambidextrous and work
with Premiere, EditDV, and FCP, and ALL of them are in turns wonderful and
frustrating in very different ways.
Cheers,
Adam Wilt



Zebra - "Perry"

John Jackman posted:
>But now the interesting part. I have a fairly early VX1000, and in its
early life the zebra came on at around 80 IRE. After a trip in to Sony
for service, it came back with 100 IRE zebra. So I guess they changed
the spec, if you have an early one you'll have to check it on a scope.
But if it goes in for service, they set all the parameters to current
spec.<
Since VX-1000 are 'zoned', I wonder if they set the zebra up differently for
each; since it is supposed to be used to set skin tone levels. The original
70% level on broadcast cameras related to typical Japanese tones which would
naturally be a little darker than 'White' faces.
On the broadcast cameras it has usually been continually variable, and I've
always set my cameras to be 100% which I think is far more useful. Rather
dangerous for 'borrowers' though who expect it to be less! The latest
broadcast cameras have 2 zebras both working at once, but fortunately you
can opt to switch either off! The lower one acts as a 'window' level and
has both an on and off threshold, the upper one has only a low threshold.
On some cameras the zebra still works when bars are selected, so you can get
a quick check.
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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