I have only managed to try out my Quark Calcium-H filter once and I wasn’t impressed with the view – blue background with black sunspots but no detail.
I asked Gary Palmer today for advice @ the International Astronomy Show.
Baader UV-IR cut filters cut off calcium UV light so do not work with Quark Ca-H filter.
Daystar’s own UV-IR filter, Astronomics, both work well, so use one of these instead – I have Daystar filter so should be OK. Should not cut off at 400, instead needs to go below or around 370 – go on to Daystar site has cut off Ca H filter line somewhere around 387 – Baader cuts off at 390 so too high.
Also can try putting calcium-H Quark directly in scope and not through diagonal to see if better focus and may also need to add in extension tube as alternative.