Testing 3D printed condenser lens

My condensor lenses are coming from China, but it will take a month before they arrive. I have a resin printer (Anycubic Photon) and a bottle of clear resin, so I gave it a go.

I used this script to generate the STL https://www.thingiverse.com/thing:2544548, please let me know if you have a better script/formula to generate the shape.

And here’s the result:

I try a different post-processing to see if I get a clearer lens, in the left I washed it just with water, and in the right I washed it in IPA and then water, and then both are cured under water, they don’t look all that different but the one without the IPA wash form a better light spot:

With IPA wash:

No IPA wash:

And of course I put them under the microscope to see what’s happening:

With IPA wash:


You can clearly see the print layers in steps.


The resin is left inbetween the layers and form a more smooth surface.

With the no IPA wash technique we already have a better-than-nothing lens, but we can do even better by sanding and then a clear varnish spray:


Left is the no IPA wash lens, the right is the with IPA wash lens after sanding and one layer of clear varnish spray, the difference is pretty clear.

This lens works but the reason I want a condenser lens is that I want to try dark-field, do we have a illumination module for dark-field? If not I can try to make one, I have some experience with OpenSCAD, or I can just draw on the back of the lens with a black marker, would that works?

1 Like

So cool. Thank you for sharing!

Black marker is usually not that black. A piece of black paper would be more effective. However a physical stop over the lens is not the best way of dark field illumination when using LEDs. Mounting the LED off-center gives more light. I have seen multiple off-centre LEDs used on OFM, but I don’t know if anyone has posted stls of the mounts.