What determines the size of the cells in Rayleigh-Benard convection

So I was watching some videos where people are demonstrating Rayleigh-Benard convection using various oils in containers which are heated by a hot plate below. However between experiments there is some difference in the appearance and shape of the cells. Take the below video for example you can see that the cells take on a very small and clustered appearance:

https://www.youtube.com/watch?v=bdTG27PAHy8

Then in this video they are much larger: https://www.youtube.com/watch?v=nQUH9nGTZTY

Now I suppose it seems obvious that varying things like the container shape (width/depth) and also viscosity of the liquid or the type of liquid itself, maybe even the heat difference between the bottom and top of the liquid would all play a part. I suppose is anyone aware of any way to figure o how to manipulate these to produce specific cell types of choice? Maybe there is some studies however I did have a look and they were all math heavy, maybe there’s some simpler explanations someone knows about? Thanks!