The Epix Gen 2 AMOLED screen only allows for 3 levels of brightness. The lowest brightness level is still extremely bright for use at night during activities.
I am assuming Garmin engineers are using PWM dimming to achieve 3 brightness levels on the AMOLED display. I measured the refreshes per second on the screen in the lowest brightness level with the screen set to always on on firmware 8.21. I filmed the screen using the 240FPS slow-mo camera setting on an iPhone. I got 8 refreshes in one second which seems very low (8hz would have noticeable flicker). This likely means that the frequency of refreshes is at least 248Hz at a minimum. The commonly acceptable low range of PWM refresh rate to avoid noticeable flickering seems to be around 200-250Hz from sources below. Garmin: what is the frequency of the lowest level of dimming if using PWM?
Could Garmin engineers look into providing more levels of dimming and a dimmer lowest setting? Greater flicker control may be achieved by using DC dimming for new lower settings and PWM at higher brightness levels. This could also increase battery life on the Epix. It could come at the expense of some color accuracy though. One could justify this by adding a “Battery Saver” brightness mode where colors are less vibrant but the watch lasts longer. This could significantly aid ultra runners who are looking to keep GPS and HR on at the same time and make it through a race on a single change a few years down the line once the battery has degraded.
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