psychopy.org | Reference | Downloads | Github

Avoid stretched gratings with rotation in the builder

If this template helps then use it. If not then just delete and start from scratch.

OS (e.g. Win10): Win 10
PsychoPy version (e.g. 1.84.x): 2021.2.3

I am trying to build a routine within a loop for a standard RSVP with foucault gratings of fixed frequency and rotated for each condition. As of now, the gratings’ frequency vary and they seem stretched at each new rotation. It mentioned in the documentation of GratingStim that one should account for the image aspect ratio when rotated in order to avoid such stretching.

How can this be achieved in the builder?

Hi @pierrecu , just wondering if the stretched stim is related to using Norm screen units. Have you tried the same thing using height units?
https://www.psychopy.org/general/units.html#height-units