[visionlist] summary of CRT info

[Max Snodderly]

Thanks to the many colleagues who offered information and advice on the
status of fast CRT displays.  

Here is a summary of some of the most pertinent comments on color displays:
There are 3, 21 inch models currently being sold that have specs that are
attractive.  

However, there are doubts whether they actually reach the maxima that are
listed.  This is dependent on specifics of the video signals, so if anyone
has been able to squeeze more performance out of these units, the rest of
the community would be grateful to know how to do it.  

Some other comments relevant to timing are offered at the end of the
message.  

Hopefully, by sharing information we can save each other some work, leaving
time for the more interesting problems.

 

*******************************************************************

NEC lists model AS120-BK, frame rate 200 Hz, resolution 640 x 480.  

 

Frank H. Durgin [fdurgin1 at swarthmore.edu] has tested it and reports the
following:

I bought one of the NEC AS120-BK monitors after searching on the web for a
200 Hz CRT.

Although the specifications available on the web indicated 188 Hz is
possible, mine came in a box indicating that 160 Hz is the highest refresh
possible. 

Indeed, when I use SwitchResX

to ask higher refresh rates,  a message comes on the monitor indicating that
the signal is out of range.

The message goes on to say that it will only accept vertical frequencies up
to 160 Hz.

The peak horizontal frequency it says it will accept is 96 kHz.

It seems to be telling the truth. Perhaps someone else knows a way to fool
it.

 

NEC tech support expressed surprise and finished by suggesting I might be
able to "clamp" the monitor using the on-screen menus, but I see nothing
called "clamp", nor anything else likely to work.

 

The image quality is good for their presets (800 x 600 @ 120 Hz and 640 x
480 @ 160 Hz).

I created a setting of 720 x 540 that looks good @ 150 Hz.

At 800 x 600 I think you could get close to 150, but I'd recommend about 144
Hz.

 

Frank Durgin

 

PS It's not exactly a flat screen either.  NEC: Not Even Close

 

********************************************************************

ViewSonic lists model G225fB, frame rate 160 Hz, resolution 800 x 600

 

Yury Petrov [y.petrov at neu.edu] has tested this one and he reports: 

 

ViewSonic G225f recommended settings are 1600x1200 at 85Hz. It goes up to
1024x768 at 150Hz, and it looks good with Nvidia GeFource 7900 GT.  

But it won't work at higher frequencies even for 800x600.

 

*********************************************************************

Samsung lists model Syncmaster 1100MB, frame rate 160 Hz, resolution 800 x
600?

 

Hans Irtel has one of these and he might check it out if others are
interested  [irtel at psychologie.uni-mannheim.de]

 

*********************************************************************

A couple of other timing issues were noted.

Adam Reeves reported that some color phosphors do not decay as rapidly as
others.  If doing a fast color shift this can give rise to a potential
luminance artifact that needs to be avoided.  

If anyone has current information on the phosphor decay rates or how to
trace back to the suppliers of the phosphors, some list members would like
to know it.

Mickey Rowe cautioned that running at high frame rates raises the risk of
dropped frames, which is dependent on your control hardware.  

Michele Rucci and Fabrizio Santini integrate a photocell monitor into their
system to guard against dropped frames and eliminate contaminated data.

 

 

 

Max Snodderly

Professor, Human Ecology/ Nutritional Sciences

and Institute for Neuroscience

1 University Station/ A2700

The University of Texas

Austin, Texas 78712

Office: (512) 232-3307

Cell: (512) 922-8777

Fax: (512) 471-4661

email:max.snodderly at mail.utexas.edu

 

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