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Re: Can a good quark replace blocking filters?

Posted: Thu Apr 21, 2016 3:00 am
by george9
Others are more expert, but for me, I just turned the question around. The Quark is a self-contained H-alpha filter as long as you don't fry it. So if you have a scope with an ERF it should work fine with a Quark. The fact that you have another etalon in series in there too should be fine without the blocking filter. It might be dark with a small sweet spot, but should be high contrast as long as they are both centered on band.

I think the combo Quark comes without the collimating assembly, so getting that one avoids removing anything. I suspect it will be superior because the original Quark has only a 12mm blocking filter (don't need any bigger because a magnifier follows it) and when you remove the internal magnifier, it means you have just constricted your 21mm Quark etalon to 12mm instead of 21mm. I don't have one to measure, but I am guessing that the combo Quark comes with a 21mm blocking filter. (I.e., the original and combo Quark cost the same because one comes with a bigger blocking filter and the other comes with a magnifier.)

George

Re: Can a good quark replace blocking filters?

Posted: Sat Apr 23, 2016 7:58 am
by fjabet
But it doesn't work the other way around, ie you can't use the Andover blocker for Coronado or Lunt as there finesse is lower and the comb frequency distribution is narrower on air spaced etalon.