Hi, I am relatively new to Builder (I use 2024.2.4 version, running under Win 11, on a laptop w 60 Hz monitor refresh rate). I have two questions: 1. I would like to have a precise timing in my small in-lab experiment. I noticed that even though I set e.g. 1 or 2 sec (or the equivalent frame(N) for images as duration (and 0 sec as onset) it is not exactly the duration for which my stimuli are presented. I guess because of monitor refresh rate as the deviations are within the 16-17 msec range. Can I make the presentation precise, like exactly 1000 msec or 400 msec? 2. I also noticed some weird things in the output, regarding the timing. The start of the routine containing only an image and a variable (that is supposed to give the exact time of the beginning of the image presentation - calls datetime.now()) and the start of the actual image is not the same - see pic attached. While the discrepancy is not that large, it still bothers me, especially because I don’t understand the reasons behind it. I would really appreciate if anyone could answer these questions. Thanks in advance!
The number of milliseconds your stimulus is presented for is limited by your refresh rate I’m afraid - as the monitor refreshing is what presents the stimulus. What you can do however is set your stimulus duration using n frames rather than seconds, so you don’t get any discrepancy from rounding e.g. 1000ms to the nearest 1/60s frame.