Millisecond Forums

How to define a position with absolute length units (e.g. pt & pc)

https://forums.millisecond.com/Topic29231.aspx

By Yat_Zoeng - 6/13/2020

Hi, everyone. I came across the problem of defining the position of a stimulus with absolute length scale. I need to set a picture right next to the fixxing point in the middle of the screen with a distance of 7° visual angle. So the picture is approxiamtely 13.55pc from the center. I wonder how I can actualize this position defination regardless of the screen size and resolution of the monitor.
By Dave - 6/15/2020

Yat_Zoeng - 6/14/2020
Hi, everyone. I came across the problem of defining the position of a stimulus with absolute length scale. I need to set a picture right next to the fixxing point in the middle of the screen with a distance of 7° visual angle. So the picture is approxiamtely 13.55pc from the center. I wonder how I can actualize this position defination regardless of the screen size and resolution of the monitor.

Visual angle is dependent on the viewer's distance from the screen, so this is not answerable.
By Yat_Zoeng - 6/15/2020

Dave - 6/15/2020
Yat_Zoeng - 6/14/2020
Hi, everyone. I came across the problem of defining the position of a stimulus with absolute length scale. I need to set a picture right next to the fixxing point in the middle of the screen with a distance of 7° visual angle. So the picture is approxiamtely 13.55pc from the center. I wonder how I can actualize this position defination regardless of the screen size and resolution of the monitor.

Visual angle is dependent on the viewer's distance from the screen, so this is not answerable.
Yes. We assume that the sbjs are 50cm from the monitor, and that's 13.55pc*13.55pc for the stimulus under the requirement of 7°visual angle. That can be a fix value.​

Thx for ur reply btw​​
By Dave - 6/15/2020

Yat_Zoeng - 6/15/2020
Dave - 6/15/2020
Yat_Zoeng - 6/14/2020
Hi, everyone. I came across the problem of defining the position of a stimulus with absolute length scale. I need to set a picture right next to the fixxing point in the middle of the screen with a distance of 7° visual angle. So the picture is approxiamtely 13.55pc from the center. I wonder how I can actualize this position defination regardless of the screen size and resolution of the monitor.

Visual angle is dependent on the viewer's distance from the screen, so this is not answerable.
Yes. We assume that the sbjs are 50cm from the monitor, and that's 13.55pc*13.55pc for the stimulus under the requirement of 7°visual angle. That can be a fix value.

Thx for ur reply btw

Okay. Then see https://www.millisecond.com/forums/Topic14608.aspx for how to present stimuli at fixed physical sizes and/or at fixed physical positions.
By Yat_Zoeng - 6/15/2020

Dave - 6/15/2020
Yat_Zoeng - 6/15/2020
Dave - 6/15/2020
Yat_Zoeng - 6/14/2020
Hi, everyone. I came across the problem of defining the position of a stimulus with absolute length scale. I need to set a picture right next to the fixxing point in the middle of the screen with a distance of 7° visual angle. So the picture is approxiamtely 13.55pc from the center. I wonder how I can actualize this position defination regardless of the screen size and resolution of the monitor.

Visual angle is dependent on the viewer's distance from the screen, so this is not answerable.
Yes. We assume that the sbjs are 50cm from the monitor, and that's 13.55pc*13.55pc for the stimulus under the requirement of 7°visual angle. That can be a fix value.

Thx for ur reply btw

Okay. Then see https://www.millisecond.com/forums/Topic14608.aspx for how to present stimuli at fixed physical sizes and/or at fixed physical positions.

Wow, that should be amazingly helpful. Thx a lot! :)