• Equipment-GamingMonitors

Information about LCD monitors

LCDs for retinal stabilization

When setting up a monitor for testing:

• Make sure you're using a photocell
• Run an experiment so that you can see if there is lag time
• "Enable" the photocell in your experiment

What to look for when analyzing a monitor with a photocell:

• When plotting the voltage, if you're getting values around 0, then either (1) your gain setting is too low and the photocell is not sensitive enough, or (b) you're not placing the photocell on a flashing background.
• Make sure that there are no low frequencies occurring during the trial - this means that the monitor is not reaching the same voltage during every frame.
• Make sure to take not of any missed frames. This is when the voltage is 0 for more than 1 frame within the trial.
• Count the frequency of missed frame throughout the experiment

Other useful links (courtesy of Jake Yates!):

https://www.blurbusters.com/

https://display-corner.epfl.ch

Monitor List

*Label is peeling off.

**Marketed as "G-Sync compatible."

Testing Equipment

Photocell: OPT101P

• datasheet: https://www.ti.com/lit/ds/symlink/opt101.pdf?ts=1639079672427&ref_url=https%253A%252F%252Fwww.google.com%252F

Monitor Info

ASUS ROG SWIFT PG259QNR 360 Hz

A refresh rate of 360 Hz was confirmed on December 3, 2021, but issues with refresh rate and luminance range discovered: Asus PG259QNR 360Hz Refresh Rate updated June 15, 2017.

Linearization is done by RL on 2022-02-25; Monitor setting is contrast=25, brightness = 0, six-axis saturation = 127 for all; see OPUS/aplab/Monitors/ASUS_ROG_SWIFT_PG25QBR/LuminanceLinearization/2022-02-25

One gamma value for all channels: gamma = 2.13 Linearizarion_OneGamma.pdf

Separate gamma value for RGB channels: RGB = 2.04, 2.17, 2.18 Linearization_SeparateGamma.pdf

ASUS ROG SWIFT PG258 (dDPI)

• 302.6 mm height
• 543.7 mm wide
• 1920 x 1080 resolution

• https://www.displayspecifications.com/en/model/8b2a95a

An ASUS ROG SWIFT PG258 (https://www.asus.com/us/Monitors/ROG-SWIFT-PG258Q/) was setup for psychophysical experiment in June 2017.

A refresh rate of 200 Hz was confirmed on June 15: Asus 258 refresh rate updated June 15, 2017.

Corresponding code and data located on OPUS - \APLAB\Monitors\ASUS_ROG_SWIFT_PG258\

Linear color calibration was conducted on several monitors of this type. Here is a confirmation of linearity for ASUS258 FACE currently located in the DDPI room. data_ASUS258_FACE_2018_07_26.pdf using parameters determined from calibration of monitors in the DPI room. As of June 25, 2021, similar parameters were sufficiently linear in the MK2 system ASUS_258_2021_06_25.pdf

Note(RL 2022/01/27): default settings by physical buttons: scenery mode; brightness&contrast 0, saturation 50; OD off;

Additional monitor luminance data collected Jan 2022 by MAC for the subject monitor in the MK2 room running at 240Hz using the colormeter and PTB-based toolbox. See OPUS/aplab/Monitors/ASUS_ROG_SWIFT_PG258/2022-01-31-Mk2SubjectMonitorLuminanceMeasurments/

ASUS ROG SWIFT PG278 (not used)

• 335.6 mm height
• 596.7 mm wide
• Upto 2560 x 1440 resolution

• https://www.displayspecifications.com/en/model/bca217

Monitor specs: (https://www.asus.com/us/Monitors/ROG_SWIFT_PG278Q/)

A refresh rate of 144 Hz was confirmed on August 8:Asus 278 refresh rate updated August 8, 2017.

Corresponding code and data located on OPUS - \APLAB\Monitors\ASUS_ROG_SWIFT_PG278\

Here is a confirmation of linearity for ASUS278 currently not used. ASUS278_2018_07_27.pdf.

Gamma correction report ASUS278_2018_09_19.pdf.

ACER Predator XB272 (dDPI)

• 336.1 mm height
• 597.6 mm wide
• can go to 200Hz
• 1920 x 1080 resolution

• linearization: R: 2.19; G: 2.21, B: 2.23 at luminance 50 & contrast 50

• luminance-step mapping: L = 0.1682 + 0.0633*step (see attachment: gamma_corrected_gray)

• https://www.displayspecifications.com/en/model/ad55945

• https://www.acer.com/ac/en/GB/content/predator-model/UM.HX2EE.005

• ACER272_tests_October2018.pdf

• ACER272_tests_Dec2018.pdf

• ACER272_tests_Jan2019.pdf

• gamma_corrected_gray.fig

BenQ XL2740 (not used)

• Access service menu: Turn off the monitor, then press and hold menu button #2 from the bottom. While holding this button, press the power button to turn the monitor on. The lights will flash, and when the monitor has turned on press button #2 once to enter the service menu. In the service menu use button #5 (up), #4 (down) and #3 (select) to navigate the menu.

• This monitor does not support GSync currently

• This monitor was tested on the DPI and dDPI (documents frame skipping NOT synced with Eyeris) : see the report BenQ.pdf

Photocell with LCD Monitors DPI Experiments

• [Janis] To see a normal signal from the LCD monitors to test their refresh rate (i.e., above) I had to max out the brightness and contrast of the monitor because the signal is not visible when the brightness and contrast are both 0.
• In Oct/Nov of 2018, Janis observed that her photocell data looked weird from the LCD.
• On 11/19/2018, Ruei and MAC discovered that the photocell had a broken connection which Ruei soldered before MAC and Janis ran an pilot session with the DPI.

• As of 11/19/2018, Photocell data collected during the Stabilized Binocular Rivalry experiments (MAC & Janis) looks abnormal (Plots from 2 sessions of Stabilized Binocular Rivalry experiments, one before discovering the broken connection and one after: 20181108.png 20181119.png)

• Janis ran a FFT of data from week of 11/19 which showed two major components at 60 and 100Hz (though we would expect only a 100hz component) though the signal itself looked noisy.

• Current options is that experimenter needs to carefully set the contrast and brightness of the LCD monitors to get a good photocell signal.