This also seems to happen when we are taking an image of a monitor/tv from our phone. My explanation is that each pixel on the phone's camera has to capture multiple pixels of the monitor, and thus there is some downsampling going on. But as soon as the photo is clicked, the phone performs antialiasing, and this effect goes away.
RK900
The 2nd image can be imagined as if we're overlaying even rows onto the even columns of the image. I found this visualization and explanation from WolframAlpha intuitive: https://mathworld.wolfram.com/MoirePattern.html.
melodysifry
I've always wondered what exactly this effect was when I've seen it and where it comes from- for example, when taking a picture of something on my computer screen, I've always noticed this type of Moire pattern and wondered where it was coming from. It's super interesting to be able to actually put a name to this effect, and understand where it comes from!
This also seems to happen when we are taking an image of a monitor/tv from our phone. My explanation is that each pixel on the phone's camera has to capture multiple pixels of the monitor, and thus there is some downsampling going on. But as soon as the photo is clicked, the phone performs antialiasing, and this effect goes away.
The 2nd image can be imagined as if we're overlaying even rows onto the even columns of the image. I found this visualization and explanation from WolframAlpha intuitive: https://mathworld.wolfram.com/MoirePattern.html.
I've always wondered what exactly this effect was when I've seen it and where it comes from- for example, when taking a picture of something on my computer screen, I've always noticed this type of Moire pattern and wondered where it was coming from. It's super interesting to be able to actually put a name to this effect, and understand where it comes from!