Well, in the end we were successful, relatively speaking. Here is
the solution we used, followed by a summary of the responses I got.
Enjoy....
=====================================================================
We managed to get our tape, although it took a lot of phoning and
lot of stupid questions on my part 8-)
We ended up using a SONY DXC-537 commercial camera. Cost of the camera
itself is in the $20,000 range. We rented it from Matrix Professional
Video Productions in Vancouver, B.C. My thanks to Bruce Lilly from
Sony and the folks at Matrix who helped us out. The rental was a bit
steep, but it did the job. Here is the blurb from Bruce Lilly
explaining why this camera works. There is another blurb from
Ken May at AT&T Bell Labs saying they have used the camera succesfully
also.
>There are cameras with electronic shutters which can be
>synchronized to the CRT refresh rate to eliminate the band which
>would otherwise occur in the video signal (e.g. Sony DXC-537;
>the feature on this camera is called "clear-scan", I believe;
>the range of synchronization is something like 57 Hz to 120 Hz;
>consult a Sony Business and Professional Group sales office for
>more information, in the USA, call (201) 930-1000 if you cannot
>locate a sales office).
>
>--
> Bruce Lilly blilly!bruce@Broadcast.Sony.COM
> ...uunet!sonyusa!sonyd1!blilly!bruce
The frequency we used was 65.9 Hz if my memory serves me correctly.
This camera worked great! The acting/speakers in the video may have
lacked some what, but the camera worked great 8-).
Another cheap possibility is the software that controls the SUN's scan
rate. This is a dangerous thing to do unless your monitor is still under
warranty 8-), but it might work. We decided not to risk it and went with
the Sony camera.
Heres the summary....
===============================================================================
Date: Wed, 27 Nov 91 03:01:46 EST
From: wade@cs.utk.edu
Status: R
For around $10,000 you can buy a box that you attach between CPU
and the monitor. It takes the Sun video signal and converts to
to something you can attach to a VCR. We use it for just what
you're describing.
If can get you some information on it if you're still interested.
-reed
wade@cs.utk.edu
-----------------------------------------------------------------------------
Reply-To: paul@brazos.Central.Sun.COM
Organization: Sun Microsystems
Your problem is that a sun monitor (depending on which one) runs at 66 or 76 hz,
and your camcorder runs at a completely different hz.
There are folks in the yellow pages of any given city, who have professional
cameras with variable hz speeds to enable doing video demos.
Barring that, there are several S Bus cards available ranging in price from
$899.00 to 15,000.00 which will convert the RGB video output to NTSC or PAL
for recording.
Paul Brackett
-----------------------------------------------------------------------------
From: henry@cs.arizona.edu (Tyson R. Henry)
Date: 27 Nov 91 18:20:27 GMT
In article <bcorrie.691180615@csr> bcorrie@csr.UVic.CA (Brian Corrie) writes:
>Hello net.world,
>
>I have a small problem. We have a demo that we want to video tape.
>
>So my question is, is there something I can do to reduce or remove this
>problem. Use a different type of monitor, different type of camera,
>different lighting, etc???? Failing a solution in that area, is there
>hardware availiable for taking the RGB output of the SUN monitor, and
>converting directly to NTSC output in some form, so it can go straight
>to video tape. Descriptions and prices would be most helpful.
>
There is a machine called a scan converter that converts RGB into NTSC
(the standard US TV format). Scan converters cost between $16-27,000.
The major difference in price is the difference in the quality of the
output. They all allow you to pan and zoom, but the Chromatek ($24k)
allows you to zoom in so close that you get 6% of the screen. The
Lyon-Lamp ($27) produces the best output.
Scan converters are so expensive because they are general tools that
work with a huge variety of computer displays. Scan converter boards
are made for many individual machines, including the sun. I have heard
that the video quality from all of the boards is poor.
Another option that I find hard to believe is that the scan rate on the
Sun can be controlled by software. I heard about this second hand and
don't know much about it. I guess the idea is to slow down the scan rate
so it matches or is slower than the video camera's scan rate.
A final option is to do your demo on a DEC workstation, they are much
easier to video tape.
`Tyson Henry (henry@cs.arizona.edu)
-----------------------------------------------------------------------------
Date: Wed, 27 Nov 91 16:32:13 CST
From: John T. West <surfer@ERC.MsState.Edu>
chap-o solution:
if it's X windows based software, open a window on an SGI and point
the camera at it's screen!
real solution:
spend $25k for a Lyon Lamb RTC scan converter....
be warned that most scan converter's won't help you because when you
downgrade a high-res computer monitor to video level resolution, you
won't be able to read the text in the buttons without zooming in on
them!!!
...so, basically there is no easy&cheap way that I've seen
hangin' ten:
-John West- MSUNSFERC4CFS surfer@erc.msstate.edu
Engineering Research Center for Computational Field Simulation
Mississippi State University ***** National Science Foundation
P.O. Box 6176 (601) 325-2094 (my voice) x8278 (secretary)
Mississippi State, MS 39762 (601) 325-7692 (fax)
Shipping address: 2 Research Boulevard, Starkville, MS 39759
-----------------------------------------------------------------------------
Date: Wed, 27 Nov 91 17:13:29 PST
From: tessi!steve@nosun.West.Sun.COM (Steve Willoughby)
In comp.graphics.visualization you write:
>Hello net.world,
>I have a small problem. We have a demo that we want to video tape. It
>is basically an interactive demonstration of an application, so we want
>to tape what is happening on the monitor. The monitor is a standard SUN
>monitor. The problem is that we get a lot of flicker from the refresh of
>the monitor. It is quite distracting, as it is a band of about one sixth
>of the screens width scrolling across the screen at maybe 3-4 times a
>second. We tried both VHS and SVHS cameras, both with the same results.
>The demo as taped in this manner is essentially useless. OK, so its
>a BIG problem! 8-(
I suspect that the only solution would be to buy a sun video-to-NTSC
converter box that will go between the sun and video deck. Since there
is such a difference between scan rates, these boxes are expensive.
If you find an easier solution, I'd like a copy.
Thanks,
--
Steve Willoughby N7PFJ |-------------------------------------
Systems Administrator | "There's no point in being grown up
Test Systems Strategies, Beaverton, OR | if you can't be childish sometimes."
Sun.COM!nosun!tessi!steve | -- Dr. Who
-----------------------------------------------------------------------------
Date: Wed, 27 Nov 91 21:56:03 PST
From: larson@snmp.sri.com (Alan Larson)
In article <bcorrie.691261851@csr> you write:
>Hello net.world,
>
>I have a small problem. We have a demo that we want to video tape. It
>is basically an interactive demonstration of an application, so we want
>to tape what is happening on the monitor. The monitor is a standard SUN
>monitor. The problem is that we get a lot of flicker from the refresh of
>the monitor. It is quite distracting, as it is a band of about one sixth
>of the screens width scrolling across the screen at maybe 3-4 times a
>second. We tried both VHS and SVHS cameras, both with the same results.
>The demo as taped in this manner is essentially useless. OK, so its
>a BIG problem! 8-(
It has nothing to do with the format of the tape recorder mounted
in the back end of the camera box. It has to do with differing scan
rates.
>So my question is, is there something I can do to reduce or remove this
>problem. Use a different type of monitor, different type of camera,
>different lighting, etc???? Failing a solution in that area, is there
>hardware availiable for taking the RGB output of the SUN monitor, and
>converting directly to NTSC output in some form, so it can go straight
>to video tape. Descriptions and prices would be most helpful.
The CCD cameras have no persistence between fields. You need to
use a tube camera with 'memory'. Try getting a tube camera. It
will probably do just fine, but you could increase the 'memory' and
reduce the flicker by closing the lens down a bit, and adjusting
the beam current (normally done automatically as a response to the
lower light hitting the tube) -- this will increase the memory and
reduce the flicker.
Alan
-----------------------------------------------------------------------------
From: bruce@blilly.UUCP (Bruce Lilly)
Subject: Re: How do I video tape from a SUN?
In article <10022@optima.cs.arizona.edu> henry@cs.arizona.edu (Tyson R. Henry) writes:
>
>Another option that I find hard to believe is that the scan rate on the
>Sun can be controlled by software. I heard about this second hand and
>don't know much about it. I guess the idea is to slow down the scan rate
>so it matches or is slower than the video camera's scan rate.
There are cameras with electronic shutters which can be
synchronized to the CRT refresh rate to eliminate the band which
would otherwise occur in the video signal (e.g. Sony DXC-537;
the feature on this camera is called "clear-scan", I believe;
the range of synchronization is something like 57 Hz to 120 Hz;
consult a Sony Business and Professional Group sales office for
more information, in the USA, call (201) 930-1000 if you cannot
locate a sales office).
--
Bruce Lilly blilly!bruce@Broadcast.Sony.COM
...uunet!sonyusa!sonyd1!blilly!bruce
-----------------------------------------------------------------------------
Date: Mon, 2 Dec 91 20:13:23 EST
From: djk@division.cs.columbia.edu (David Kurlander)
Software was posted on the net that changes the refresh rate of Sun
standard *Monochrome* SparcStation 1+ displays to 60hz, which produces
much better results when videotaping. The code probably works with
the standard monochrome displays for the entire sparcstation line, but
but it doesn't work with color. If you would like this code, let me
know.
David Kurlander
-----------------------------------------------------------------------------
Subject: Re: How do I video tape from a SUN?
From: Mark Thompson <mark@westford.ccur.com>
In article <bcorrie.691180615@csr> you write:
>Hello net.world,
>
>I have a small problem. We have a demo that we want to video tape.
>The monitor is a standard SUN monitor.
>is there hardware availiable for taking the RGB output of the SUN monitor, and
>converting directly to NTSC output in some form, so it can go straight
>to video tape.
There is only one good method for doing this, an RGB scan converter.
Several companies make them including RGB Spectrum, Lyon Lamb, and
Folsum Research. At Concurrent, we also needed to tape a demo from
one of our hires monitors. Since scan converters are expensive, good
ones start at $10K, we rented one. We paid $300/day for an RGB Spectrum
converter that worked flawlessly. They have outputs for VHS, Y/C (S-VHS),
and component Betacam SP. For demos, renting is most likey your best
and most cost effective option. Note, most good scan converters will work
with nearly any display, including your Sun.
%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~%
% ` ' Mark Thompson CONCURRENT COMPUTER %
% --==* RADIANT *==-- mark@westford.ccur.com Principal Graphics %
% ' Image ` ...!uunet!masscomp!mark Hardware Architect %
% Productions (508)392-2480 (603)424-1829 & General Nuisance %
% %
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----------------------------------------------------------------------------
From: ed@sunvcr.Canada.Sun.COM (Ed Bryant [Sun Vancouver Sales])
Subject: Re: Video taping a SUN monitor
You might experience some (significant) loss by going to projection and
then videotaping.
Two solutions that I have seen:
1. Variable shutter speed cameras. I have seen this work with a 16mm movie
camera, but don't know if it will work with video. The basic idea is that
you have an external sensor, which is placed near the monitor, and picks
up the 66 Hz refresh signal, and uses that to drive the shutter on
the camera. By tweaking the adjustment, you can move the refresh frame
off the visible portion of the screen. I have never encountered a camera
like this, but it must be possible.
2. Video encoder. This is a piece of hardware that takes Sun RGB signals in
directly, and outputs a composite (or perhaps component) NTSC signal,
suitable for direct input into a VCR (rather than a camera). The bonus
here is that no optics are required (ie. no camera). Don't know if you
could find one of these around to rent, etc.
Another off the wall suggestion is the new RasterOps card that does video
in and video out. For the video out stuff, I'm not certain how it shows up
to the system, perhaps as a 640x480 frame buffer, and whether you could run
window systems and/or apps on it.
That's my thoughts. Let me know what you do... I get a few calls from
people looking at this, but I never find out what they did.
regards,
Ed Bryant
Sun - Vancouver
-----------------------------------------------------------------------------
To: Kenneth_A_Pier.PARC@xerox.com
Subject: bwfreq.c
Hi Ken,
I just got this code from David Kurlander at Columbia. It sounds like
you have used it before. Is this true. David said he never used it, so
I am looking for someone who has first hand knowledge. My main worry is
just what is the lenght of an ``extended period of time''. Our technicians
say that it is hard to say, but they are worried about anything over 5
or ten minutes without some extra cooling for the monitor. If you did use
this Gem of a hack, how long did you run it for.
Enquiring minds want to know.....
Brian Corrie (bcorrie@csr.uvic.ca)
-----------------------------------------------------------------------------
>From Kenneth_A_Pier.PARC@xerox.com Fri Dec 6 13:16:58 1991
First, if you should be caught or killed I will deny any knowledge of your
activities.
Second, we have run bwfreqed monitors for long enough to make videotapes of
screen shots; i.e. an hour at a time. Remember that this code is intended only
for SPARCstations with black-and-white monitors of the "bwtwo" type. To
discover your monitor type, look in your console log at your booting messages,
or boot a machine and watch what it says after the sd0 and sd1 messages.
Good luck, Brian.
-----------------------------------------------------------------------------
From: kpm@cbnewsd.att.com (kenneth.p.may)
Newsgroups: rec.video
Subject: Re: Video taping a SUN monitor?
>From article <1991Dec4.121807.2232@titan.ksc.nasa.gov>, by myjak@titan.ksc.nasa.gov (Michael D. Myjak):
> Liudvikas Bukys (bukys@cs.rochester.edu) writes:
>> Or, I am told, the other thing you can do is to record on FILM and
>> transfer it back to videotape. It's pretty expensive, but I think
>> that's what you have to do to make high-quality training films,
>> commercials, etc.
Sony has introduced a new video camera the DXC537 that has a feature
called "Clear Scan" that allows computer displays to be shot without
the horizontal bands appeiaring. We tried one on several diverent
SUN displays and were very impressed with the results. Some of the
local video rental houses have this camera available.
Ken May
AT&T Bell Laboratories
Naperville, Illinois
att!ihlpv!tvmaint
(708)979-3725
-----------------------------------------------------------------------------
--
Brian Corrie (bcorrie@csr.uvic.ca)
Under the most rigorously controlled conditions of pressure, temperature,
volume, humidity and other variables, the organism will do as it damn well
pleases. Sounds like some of the code I have written...... 8-)
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