I noticed that when slicing with chitubox or the anycubic slicer, and then printing at the optimum exposure time, that all my prints are exactly 50um (one pixel width) extended in the X and Y direction. This could be due to light spreading beyond the edges of pixels, or due to a calculation error in the slicing software.

Anyway, this results in that horizontal holes are 100um (2 times 50um) smaller in the X and Y direction, and objects are 100um wider than they should be. In the Z direction, all is exactly the correct size.

Regardless of the cause, the solution is simple: Just trim one pixel of all edges in the image layers. I have made a small console app that converts a photon file in order to do this. When I convert a photon file with this app, printed pins exactly fit into printed holes, regardless of print orientation. No sanding required.

Here is the link: https://github.com/Hans2004/AnyCubic-Photon-Decrease-Pixel

I request for a feature to be added to Chitubox that does the same thing.