[visionlist] CRT monitor solutions

[Sol Simpson]

Hi Peter,

 

I am not sure. 

 

We are not LCD monitor experts and I'm just passing along info we have found
during investigating things for our eye tracking technologies, hoping they
may be useful to the general research community.

 

Thanks again,

 

Sol

 

From: Peter April [mailto:papril at vpixx.com] 
Sent: November-12-09 9:57 AM
To: Sol Simpson
Cc: visionlist at visionscience.com
Subject: Re: [visionlist] CRT monitor solutions

 

 

Hi Sol,

 

Thank you for the link.  Very informative review.  One specification that
concerns me can be found on page 6 of the review:

 

"The monitor regulates its brightness by means of backlight modulation at a
frequency of 180Hz"

 

So, the backlight is flickering at 180Hz, which then passes through the LCD
filter which is modulating at 120Hz.  Do you think this might cause a 60Hz
beat pattern in the temporal luminance profile?

 

Peter April, CEO

VPixx Technologies Inc.

Tel: (450) 723-1021

Cel: (514) 295-1341

Fax: (514) 328-7499

Email:   papril at vpixx.com

Web:     http://www.vpixx.com <http://www.vpixx.com/> 

 





 

On 2009-11-12, at 6:33 AM, Sol Simpson wrote:





Hi Peter,

 

I'm not sure.

 

I found a very detailed review of the Samsung at the link below; he even did
response time matrix tests based on color to color and shows that the 120 hz
mode gives a nice even response time across colors:

 

http://www.xbitlabs.com/articles/monitors/display/samsung-sm2233rz.html

 

He also looked at how the monitor fills the color space but I do not know if
it is better or worse than normal for an LCD.

 

I could not find a detailed review of the Viewsonic model.

 

Thanks,

 

Sol

SR Research Ltd.

www.sr-research.com

 

From:

 Peter April [mailto:papril at vpixx.com] 
Sent: November-11-09 6:15 PM
To: Sol Simpson
Cc: visionlist at visionscience.com
Subject: Re: [visionlist] CRT monitor solutions

 

 

Nice find Sol !

 

Do you have any info on the RGB resolution of the glass?  Most I've seen are
8 bits; some only 6 bits, plus some temporal dithering to "fake" 8 bits.

 

Peter April, CEO

VPixx Technologies Inc.

Tel: (450) 723-1021

Cel: (514) 295-1341

Fax: (514) 328-7499

Email:   papril at vpixx.com

Web:     http://www.vpixx.com <http://www.vpixx.com/> 

 






 

On 2009-11-11, at 6:17 AM, Sol Simpson wrote:






Hi Michael,

Yes, I think we may have lucked out with these monitors. 

The only 'downside' in terms of updating time is that they seem to update
the display in a scanning fashion like a CRT; it would have been nicer if
they updated the display all at one time like some LCDs seem to (the same
LCDS have buffering issues and long response times too though).





Perhaps one can follow the rule:

if they offer stereo, than it's an unbuffered display.


I am not sure about this. For example, the Infocus DepthQ 120 Hz DLP
projector (http://www.projectorcentral.com/pdf/projector_spec_2850.pdf) that
has been around for years has a 1 frame internal buffer (we tested and
confirmed this, and the spec sheets also reports it!). It is DLP though, not
LCD.

Thanks again,

Sol


-----Original Message-----
From: Michael Bach [mailto:Michael.Bach at uni-freiburg.de] 
Sent: November-11-09 6:07 AM
To: Sol Simpson
Subject: Re: [visionlist] CRT monitor solutions

Dear Sol:





We used the BBTK (http://www.blackboxtoolkit.co.uk/)

yes, I had already looked that up, looks good, even runs on my preferred
platform ;).





to test the timing using photo sensors and TTL outputs...

That's a perfect way to test this. But this means that you were sort of
lucky to find out that these monitors did have these desirable properties?
And others presumably didn't? It would really be great if the manufacturers
would mention this. 

Perhaps one can follow the rule: if they offer stereo, than it's an
unbuffered display.


Thanks & best, Michael.
-- 
Prof. Michael Bach PhD, Ophthalmology, University of Freiburg, Killianstr.
5, 79106 Freiburg, Germany. 
Michael.Bach at uni-freiburg.de   <http://www.michaelbach.de>






_______________________________________________
visionlist mailing list
visionlist at visionscience.com
http://visionscience.com/mailman/listinfo/visionlist

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://visionscience.com/pipermail/visionlist/attachments/20091112/c0c56a69/attachment-0001.htm