filter slides and diffraction

I was interested in a filter slide or the Moonlite focuser with the filter attachment.

Has anyone trying these types of items noticed any diffraction from the filter or slide being in the light path?

Thanks in advance

Chester

I use an Astrocrumb filter slide on my 12.5" truss Dob. I really love the convenience of the filter slide. The slide just barely intrudes into the light path and can be noticed while collimating as a small flat spot on the image of the primary. If I am not using filters, I remove the slide and there is no intrusion into the light path.

I do on occasion use filters while doing planetary observing. I have never noticed any diffraction effects from the slide.

Gary Weber