Trying the Airylab telecentric on the back of the SM90 and then double stacking with the Quark etalon produces a wider field of view as expected than using the 4.2x telecentric on the Quark, but also reduces exposure time which is always a plus. FWHM while wider is not to a deleterious effect. I think this system will get quite a bit of use when activity picks up a bit more.