Schott N-WG280

The 2mm thickness is just right for my setup, and the cut-on transition is sharp as expected. I've been using it in a fluorescence rig and the N-WG280 cleans up the excitation path perfectly.

Been hunting for a reliable 280nm longpass for weeks and this one finally gave me the clean cutoff I needed. The glass is spotless and the transmission curve matched the datasheet almost exactly.

The 2mm thickness fit perfectly into my filter holder without any wobble, and the cut-on at 280nm blocks the UV haze I was fighting in my fluorescence setup. Transmission in the visible range looks clean, no unexpected color shift at all.