Dirty glass or not?

Hey everyone, I am about to start a huge print project. I have cleaned the glass at the bottom of the printer a week or 2 ago and I realised today that the glass is not perfectly clean. It doesnt show in the photo but with the naked eye and a strong light, I can see there are some streaks from washing the surface even if I followed the instruction on the Formlab website (using a PEC pad, IPA and only vertical swipes). Can this kind of streak affect the print or I should be afraid?

Let me know!

That shouldn’t affect the prints, IMO.
The process isn’t that vulnerable to the optics of the window, that would be just silly.

The reason you’re seeing the streaks at an angle and not head on is because the residue is changing the thickness of the anti-reflective coating slightly, making it reflect the outside light differently. If you’re not seeing it head on, the laser won’t reflect off of them / be attenuated sufficiently when hitting it head-on either.

IMO, it’s better not to overdo the cleaning obsessively and scrape off the AR coating.

Thank you!!