How do you make these lenses with resin? I'm also thinking of making some custom optics for a project, can you point me to any helpful resources you used to learn how to make them, please?

Hello, as I need lenses with a short focus, I have only watched a few videos that explain the principle of the lenses. One thing I learned relatively quickly is that the thicker the lens, the shorter the focus point. I will probably write a whole tutorial about what I have found out. In any case, resin lenses work and they are great for aligning and focusing projector light sources. I think that everyone will be able to build this projector without the eternal discussion about where to get the lenses.

Yes, I see that as a big advantage, what is the process of making these lenses? I want to give it a try but not sure if a silicone mold will give me the result I want. Also, I know it would need some polishing as well, how do you do it?

I will next use a silicone mould, either homemade or bought as a baking form. I think these will work without polishing if the surface of the mould is smooth.