The £22.50 Pimoroni microscope lens is a nice upgrade. The picture quality is good, and the mechanism is simple- you twist the lens to change the zoom, and physically move the lens further or closer to your object to focus, like a microscope. The aperture appears to be fixed. I'm waiting on a (used) industrial lens to try next. https://shop.pimoroni.com/products/microscope-lens-0-12-1-8x