Hi Paul, I would have thought that your Quark Chromosphere and WO Z61 will work very well together indeed. The scope has an air-spaced, rather than an oil-spaced, doublet so you don’t have the worry of unfiltered sunlight passing through and potentially causing deterioration of any lens oil. In theory you don’t need to use the UV/IR cut filter with apertures up to 80mm, but seeing as you already possess it, then personally I would still use it, as it won’t degrade the image at all but will still bounce some energy straight back out of the system rather than allowing it all into the Quark.
The advantage of using your Quark with a 61mm aperture scope is that you will be able to get a full disk image of the Sun with a decent amount of surrounding field. I can just get a full disk with my 70mm F6.8 scope plus Quark, but it fills the field such that I cannnot see all the proms at the same time! Bigger apertures will only ever deliver a chunk of the solar disk – I get a solar ‘quadrant’ when using the Quark on my 130mm F6 scope (which I stop down to 110mm, and use with a UV/IR cut filter).
Hope this helps.
Sally