[visionlist] fast displays for vision research?

[Deborah Apthorp]

Hi Markus,

I posted on this topic a while ago & got a huge number of responses,  
which I'll try to summarise below. Briefly:

Most high-end CRT monitors can be driven at higher refresh rates than  
advertised if you sacrifice pixel resolution. You should be able to  
get up to 200Hz on a good one.

It is currently pretty hard to get new CRTs but there are a few  
suppliers in the US still selling them:

Eureka Electronics:  http://www.eurekaelectronics.com/

Widgets Inc: http://www.widgetsinc.com/shop/page199.html

Accurate IT: http://www.accurateit.com/pricelist.asp

Vision Research Graphics: http://www.vrg.com/ - these guys make a  
specialist high-speed monochrome CRT monitor.

With regard to more recent technology, have a look at Daniel Reetz's  
post which goes into this in more detail, but briefly:

There is nothing entirely adequate being sold just yet, but a few  
things look promising:

OLED (organic light-emitting diode) monitors are supposed to start  
coming out next year, according to Samsung. These should theoretically  
have good temporal properties but they've been rather slow making it  
onto the market and may not be very durable. A lot of people are  
banking on this being the next big thing but they have not been  
extensively tested for vision research yet. There are some reports of  
timing problems due to the way the displays are driven.

TMOS technology (time multiplexed optical shuttering) -  http://www.unipixel.com/home.htm 
  - this is promising, could be manufactured with existing LCD- 
manufacturing equipment, but is not yet on the market and may take  
some time (also some sources suggest there may be unforeseen technical  
difficulties in the manufacturing).

Laser technology: http://www.laservuetv.com/products.php - this is  
pretty new and is more a TV than a monitor, but we're looking into it.

LCD monitors: technology is improving for these, but the problem is  
that a lot of the technology that goes into improving the "refresh  
rate" is trade-protected and so we don't really know what is happening  
behind the scenes. Sol Simpson reports that the Samsung 2233RZ and the  
ViewSonic VX2265wm have been tested and do run at a "true" 120Hz, but  
I think further testing would be required on these models.  
Furthermore, these still rely on "twisted nematic" technology (as do  
all LCD displays) which means 6-bit rather than 8-bit colour.

With projectors, your best bet is a 3-chip DLP, according to Duje  
Tadin, but they are very expensive. The ones designed for stereo have  
very fast refresh rates, apparently. Single-chip DLPs use a colour  
wheel and are not recommended as they produce quite a lot of artefacts.

There is also a projector technology called LCoS which is apparently a  
hybrid between LCD and reflective technology: Daniel Reetz uses a JVC  
SX21 but I don't think he recommends driving it at fast refresh rates.

Laser projectors are very new on the market and there are some reports  
that the timing on these will be very good.

Commercial projectors: http://www.colorvision-lasers.com/default.aspx  
- these guys will custom build you one, but it looks very expensive.
"Pico" laser projectors: http://www.microvision.com/ - these guys make  
the cutest little pocket laser projectors that will be commercially  
available very soon.

I hope this information is of some use to you.

Cheers

Deborah Apthorp

School of Psychology, University of Sydney

On 27/11/2009, at 3:22 AM, Markus Bauer wrote:

> Hi
>
> I wonder what kind of displays are currently most recommended for  
> vision research when fast and accurate timing is important?
>
> We want to do some studies using flicker stimuli where we want to  
> manipulate the phase even at high frequencies around 50Hz and higher
> So 'refresh rates' above 100Hz and ideally above 150Hz as some CRT  
> monitors offered would be great.
>
> Are there still (fast) CRT monitors sold? where?
> Any recommendations for fast (and temporally accurate) LCD devices?
> Are Plasma devices suitable?
>
> We are interested in both monitors/screens as well as Projectors -  
> for MEG research
>
> Any help or comments would be greatly appreciated!
>
> Markus Bauer
>
>
> _______________________________________________
> visionlist mailing list
> visionlist at visionscience.com
> http://visionscience.com/mailman/listinfo/visionlist





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