ASK RICK JANUARY 2000
PANASONIC OFF COLOUR
I found the article in the October issue of
Video Camera on the topic of additional lighting very interesting. However, I
was hoping you would give advice on how to avoid some of the problems of
filming indoors, especially as the editorial correctly assumed that most
camcorder users press 'record' and hope for the best.
Recently, I have purchased a Panasonic DS33
camcorder and the only problems I have experienced regarding picture quality
was filming indoors. I have two examples. I was recording in a workshop with
very good natural daylight. The first sequence was excellent for colour. The
camera was then set to pause and pointing down to the floor whilst waiting for
the next shot. When the camera was then brought up to the eye, the scene in the
viewfinder was very grey and most of the colour had gone as I pressed record.
Needless to say, when shown on the TV the two scenes looked very different.
I wrote to Panasonic, as I thought I had a
malfunction, but the replay suggested the problem was caused by pointing the
camera at the floor and that it would take the camera about seven seconds to
readjust to fresh lighting. Try as I will I cannot reproduce the problem.
In another sequence, I was recording in a
very small, brightly lit room with one window and recessed tungsten ceiling
lights. Depending on where the camera was pointing, some shots were good for
colour while others were blue and pale. Any advice on how to avoid these
problems, without additional lighting, would be appreciated.
G. B. Turner,
Stoke On Trent
The root cause of your problem is not the type
or amount of light it sounds as though there's more than enough in both cases
but the way you are using your camcorder's white balance system. Panasonic
camcorders have a better than average reputation for colour accuracy in a wide
range of lighting conditions, but even the best white balance systems can make
mistakes, if they're not set up properly. Nevertheless, the problem in your
first scene rests squarely with you since you say that the image in the viewfinder
showed colour faults, yet you went ahead and pressed the record button anyway!
In my experience Panasonic camcorders respond to lighting changes in much less
than 7 seconds but there's no doubt that if the machine was on full auto it
would have taken a few seconds to compensate for such a big change in scene
lighting. If there were colour errors lasting for the whole scene i.e. longer
than a few seconds and since you can't reproduce the error, it's possible
that the WB system was on a manual setting. Have another look at the instructions
and get into the habit of setting white balance manually prior to each shot, it
only takes a couple of seconds.
The colour faults in the second scene are
characteristic of the way some camcorders deal with mixed lighting, when one
type of light (almost certainly the tungsten ceiling lights) predominates or
shines onto the front of the camera. The solution in this case to take care
with the framing of the shot, to avoid single points of bright light, and to aim
for a more diffuse lighting, try using white boards or reflectors out of shot.
My camcorder is a Sony DCR-PC7. I have recently
brought a VideoTech VEC-501 Multi-Scene storyboard editor. To get the full
benefit of the editor I need to be able to timecode my camcorder tape and connect
to the editor's Control L socket. Although Video Camera Buyer's Guide chart shows
my camcorder as having a timecode facility I am unable to find an 'in' socket
on the machine, other than the power socket, and I can find no instructions in
the user manual on how to put a timecode on the tape.
I am grateful for the Jargon Buster section
of your magazine but I am wondering whether the meaning of the term Timecode
has changed since my machine was introduced. Have I missed something about the
PC7 or have I been sold a pup?
I know the VCC-501 can write a timecode but
unless I can link up the camera to the editor. It will mean adding an extra
generation to the editing process, editing from a copy tape. Incidentally, a
friend who also has a VEC-501 and a Sony Hi8 camcorder has been able to set up
a timecode editing system quite easily, although we are both in our 70's, and
struggle a bit with the terminology.
The topic of timecoding is fraught with difficulties
at the best of times, but it becomes a veritable minefield when digital
camcorders are brought into the equation. The first thing to say is that all DV
recordings are timecoded by default. The digital information that makes up each
frame of a recording has a unique address that is used by digital editing
systems and PCs. Some digital camcorders notably the Digital 8 models from
Sony also record a modified version of the RCTC code on the tape. Mini DV
machines with Control L terminals can be controlled by some (though not all) edit
controllers, but will usually default to reading the standard
hours/minutes/seconds time readout. It's been a while since we last looked at
the PC7 (over 3 years in fact). However, as far as I can recall the only
timecode facility on this machine was the format standard digital data address,
accessible when the machine is connected using a FireWire connection to a PC.
You should still be able to use your edit controller with the PC7 but edits
will not be as accurate as timecode, typically cuts will be to within +/- half
a second, though this is usually sufficient for most home movies.
I wonder if you can come up with a solution
to a problem that I have during editing. The fault is a series of black
speckles or flecks that appear in the upper half of the image on screen and are
also copied to tape during recording and capture to hard drive. The editor is a
Pinnacle Studio 400, which I am basically delighted with, however, when using
the Smart Cable 006; the black marks mentioned spoil my work. My camcorder,
used for this purpose, is a Sony TR2000, I have two of these and both give the
same result. The VCR I am recording to is a Panasonic NV-HS950. The problem
doesn't occur when using the 003 Smart Cable or if I disconnect the LANC jack
from the camcorder and drive it using its own remote control. Using the 003 cable
is not an option as this will not drive my Panasonic VCR. I have two 006 cables
and both produce the same results.
If the PC is switched on and Studio 400
initialised but not used to control the camcorder the black marks are not
present, even with the LANC plug connected to the camcorder. However, as soon
as the program's VCR or camcorder controls are used the black marks appear and
remain until the PC is shut down.
Thank you for the demo tape which, shows the
marks very clearly. I have to confess it's not something I've come across
before but I have little doubt that it is being generated by the PC and fed back
to the camcorder by the LANC cable. It would have been helpful to know a bit
more about your PC but the size, position and frequency of the lines suggest
that it is probably originating from within the Studio 400 and its associated
software, rather than other open or running applications on the computer. You
might be able to confirm this by pressing Ctrl-Alt-Delete and shutting down other
programs one by one and see if that makes a difference. I don't have any
definite answers but I do have a couple of suggestions, on the assumption that
you have already exchanged the Studio 400 and re-installed the software. The first
is to reposition the board, or swap the other boards around inside the PC,
making sure that the Studio board is as far away from everything as possible. Secondly
check the cabling and ensure that power leads and ribbons are well away from
the Studio board. The only other thing I can suggest is to try your Studio 400
in another PC; if the speckles disappear then there has to be something unusual
about your computer.
BEATING THE BLUES
I have a Sony TRV310 Digital 8 camcorder.
Generally I and quite pleased with it, especially the powerful optical zoom,
however, there appears to be a problem with the white balance as I am suffering
from a definite case of the blues! I brought the camcorder in the UK in July and
after testing it everything seemed fine. Packing it away (with sachets of
silica gel) I took it out to Darwin in Australia in September and I will be
travelling around for the next few months. Trying it out around the tropical
garden of my motel I soon noticed that when using the telephoto lens, blacks,
browns and greys had a bluish tinge. Even without the telephoto I occasionally
had a problem, e.g. a white wall on one occasion but slightly blue on another.
When I video'd a black and white bird (with zoom) on green grass it turned out
dark blue and white on green grass and I knew something was wrong! Yet another
bird, white with black wingtips in a tree came out okay
Other colours are not
100% accurate but still fairly good.
I have tried every combination of controls on
the camcorder that I can think of but the only thing that makes a slight
difference is contrast there is no manual white balance.
I am a naturalist and interested in wildlife
so I need to use the telephoto lenses. What I would like to know is is this
likely to be a fault on the camcorder and could it be caused by the humid
conditions in Darwin? If so what can I do? I am beginning now to wish that I
had brought the Sony TRV510, which has a manual white balance control.
If by some chance you come across this issue
of Video Camera on your travels I trust you are not making judgements about the
colour balance of your recordings based on what you see on the 510's LCD viewing
screen. Even though LCD screens have improved enormously in the past couple of
years they are simply not reliable when it comes to assessing colour accuracy.
You should get a better idea of by connecting your camcorder up to a TV, though
even then you can't be sure that an unknown motel room TV is properly set up;
you will just have to wait until you get home for the final answer. It is just
possible that your machine suffered some damage in transit but I would have
expected any faults to be much more pronounced. I think it unlikely that the
problem is caused by high humidity since these machines are designed to work in
a wide range of temperatures and conditions.
However, assuming that the errors that you
are seeing are real and being recorded on the tape then that would indicate
that the camcorder's auto white balance system struggling. I imagine the light is
a good deal brighter and colours more intense out there and in such conditions WB
systems can over compensate or make mistakes. The simplest solution is to fit a
neutral density filter (ND4 is most suitable) to your machine, which will
reduce the amount of light entering the lens, without affecting the colour tones,
and hopefully help the machine's WB system to make more accurate assessment.
ã R. Maybury 1999 1411