I have a PST and have used it for several years with satisfaction. I also have a 60mm ED f/5.5 and a 70mm ED f/6 refractors. I am considering using the 60mm and 70mm EDs with a Quark to get improved views of the sun over that of the PST. I hesitate to purchase the Quark over a 60mm dedicated solar scope since I get the impression from reading discussions online that a dedicated solar 60mm solar scope "might" have a small visual and imaging edge over the Quark based refractors.
If I purchase the Quark, I can use it with the 70mm ED. In principle, the extra 10mm of diameter should improve my visual and imaging objectives. In practice, is 10mm significant for average seeing conditions? What level of improvement should I expect to see with a Quark and the 60mm and 70mm refractors over that of the PST and a 60mm dedicated solar scope? Does the added advantage of a Quark on a 70mm ED refractor outweigh the possible performance reduction of a 60mm dedicated solar scope?
I keep procrastinating on the choice between the Quark based 60mm and 70mm refractors and a dedicated 60mm solar scope. I don't have access to any other hydrogen-alpha telescope systems to look through, so I am trying to make the best choice by reading reviews and comments on different forums. I would like to make my decision on more than a flip of the coin which is where I've been struck for some time now. Perhaps I am making a mountain out of a mole hill in trying to make the perfect choice under these conditions.
Any advice that anyone can provide me with to solve my choice dilemma will be greatly appreciated.
If we're talking visually and keeping it light and simple to setup, then I would just get the dedicated 60mm HA scope.
If you're more interested in larger apertures, visually (demanding a more heavy duty mount too), and/or interested in larger scale imaging, then I would say consider a Quark.
You will see more with a 60mm aperture. You will see even more, with a larger aperture, but subject to the quality of your local seeing.
I have a Quark & PST and I've compared both at 40mm aperture. I setup my Quark on my ST80 (400mm F5) and stopped it down to 40mm F10 to match the PST, also 40mm F10.
Visually, the Quark had higher contrast and was bright, but more uniform (for my copy at least) Visually the PST was much brighter and had a lot less contrast, which lead it to look brighter. I could see fibrils and spicules just fine on both and proms and stuff on broth. The Quark showed better surface detail, much better, due to the much tighter bandpass resulting in higher contrast of the features from the continuum. The PST was immediate with tuning so I could go in and out of band to see different features and how the worked. The PST also was ready to go without any time at all, instant views, and the sun finder built in is just so super convenient and practical. The Quark requires more setup time, is a lot more demanding on the focuser (it's heavy with a diagonal), requires power and is not fast to tune through values to find the best setting to be on band, but the extra work pays off with a higher quality more contrasty view. Both of course subject to copy variation of the etalon.
The benefit is you can put the Quark on a 60mm, 70mm, 80mm, 100mm, 120mm, 150mm, etc, and play around with different views as seeing allows if you're ok with a bit more fuss.
The in between? The 60mm options. The larger apertures in dedicate scopes immediately push into the seriously double and triple or more cost range of something like a Quark, so with a budget like that, I would consider a lot of other options.
Edited by MalVeauX, 09 March 2019 - 01:27 PM.