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The Good, the Bad, and the
Intermittent
Part 1 - Tape Stock Issues
A very wise
videographer named Jim Billipp recently quipped, "Good is just an
intermittent that hasn't happened yet". (Jim, a client of ours since
1995, prompted us to manufacturer the original professional "Warm card"
and helped us with our new logo).
There are three
states of operation for all video gear; operating properly (good); in
some sort of failure mode (bad); and intermittent (ugly). When a unit is
functioning properly, all is well. When a unit fails consistently, you
just fix it. However, when a unit only fails intermittently, it can be
absolutely nerve racking. If the unit is sent in to us functioning
properly, it presents a big problem. With most malfunctions having
several possible causes, it's impossible to know what component to
target for the fix. And it's impractical and too expensive to fix all
possible causes.
The stories we
could tell of how we tried for days to recreate some problems in the
shop. From turning our bathroom into a "tropical room" with heaters and
humidifiers, to putting a camera in the refrigerator overnight, to
actually driving down the bumpiest road I could find while my tech,
Danny, shot video (he still has the bumps on his head). How many times
have you brought your car in for service only to find that it's not
doing what you said it is doing? You say to yourself, "I just know this
thing is gonna stall when I'm in the harbor tunnel during rush hour!"
Well video equipment is similar and in some cases even more of a problem
than your car.
Many shoots
involve great expense and are often non-recoverable events, from space
shuttle takeoffs, productions with large crews and talent, and important
interviews, to even your own or another's wedding. These are times that
you can't afford to experience any problems.
With the size
our client base, we see all sorts of problems. Many problems repeat
themselves over a product line and become common and easy to fix. The
difficulty for all of us is when we can't recreate the problem that
occurred in the field. The first thing we try to do is help you diagnose
as much of the problem as possible while it is happening, before you
send your gear in for service. This can greatly decrease the total costs
involved, including down time, shipping and repair costs. We prefer to
provide our clients with telephone support to help with this
trouble-shooting before sending the unit in for service. Too many times
we can not recreate the same problems, which causes frustrations for us
as well as clients.
In this series,
I will be discussing several problems which you may encounter
intermittently. In part one of this series I will discuss one area that
we have experience in that can help you get through those tough times
with minimum expense and client frustration.
Tape Stock Issues
- Head Clogs
With videotape,
clogs happen. Hopefully, you will get an RF warning from the recorder
and can quickly clean your heads and get up and running again. Depending
on the severity of the clog, you may not always get an RF warning, so be
sure to check playback as often as possible.
While there is a
lot of quality control in the manufacture of tape stock, there can be
some bad batches and even recorder or environmental problems which can
contribute to head clogs and severe drop-outs. High heat and humidity
for example, can reek havoc on perfectly good tape stock
What can you do
to minimize problems? First realize that you have been lucky if you have
never experienced one. We rarely hear from clients who have never
experienced a head clog after years of shooting. When we do, it is the
exception not the rule. Tape stock and environment play a large part in
the head clog problem. All videotape decks have a number of stationary
and rotating heads that record and playback video, audio, time-code, and
control track signals. Each of these heads is subject to clogging.
High speed
rotating video heads lay down incredible amounts of video, audio, and
time code information, the amount depends upon actual tape format of
course. At times, spots that have missing RF signal interrupt playback
of this recorded signal. This is called a dropout. Small dropouts are
common and normal and don't even show up in playback because of playback
dropout compensation in the analog world and error correction with
digital playbacks. Unfortunately, with high dropout rates or massive
head clogs these circuits are of little use.
Being diligent
with head cleaning and frequent spot checking of recorded video is the
best way to keep ahead of intermittent recording problems, but there are
other things that should be considered beyond keeping heads cleaned.
Over the last thirty-five years of experience with tape manufacturers,
we have come across a number of bad runs of stock. When problems all of
a sudden begin to happen and you find yourself having to clean your
heads frequently, switch to another batch or tape brand all together,
then notify your tape supplier. They will welcome feedback because of
the competition for your tape business.
When you have
had excellent results with a particular stock or brand, stick with it.
Often problems occur after switching to a less expensive product that
may not have the quality that you have been accustomed to. With the
smaller format, ¼ inch digital decks from DV, DVCAM, to DVCPROHD, it is
very important to use the highest quality tape stock that is recommended
by the manufacturer as your starting place. Nobody knows better and has
as much control of the recording process as a manufacturer that makes
the recorders and tape stock.
With that said,
there are other tapes stocks that can be as good and in some situations
better. Ask others what they recommend and use. Consider that different
tape manufacturer's formulations include some with materials that act as
lubrication of video heads to extend head life, and some with materials
that are abrasive, which in effect clean the heads as they record or
play. When a client expresses a desire for reliability, I recommended
one popular brand with near problem free recordings because of its
inherent self-cleaning action. If long head life is the main concern, I
recommend another brand because of its low abrasive nature and resulting
long head life. Clients should make up there own mind what is more
important, reliability or head life. Over time however, tape
manufacturers change formulations so that the past is not always what's
happening in the present. This would be a good topic of a video news
group. Ask others what their experience has been with different tape
stocks, and notify the group when you see bad runs of stock.
Another
important tip that can go a long way in saving your relationship with
your client is when you suspect you have a tape problem, grab another
tape from the suspect batch and make a short recording. This tape can be
used as evidence if the tape stock proves to be bad. We have used some
of these tapes in the past and have made bad recordings on a number of
other decks in the shop. Why should your equipment be blamed when it may
be the tape stock your client provided?
In my next
article I will be discussing the effect the video heads have on
minimizing tape problems.
Take care,
Roger
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