Combo Quark

[David Smith]

Anyone seen this yet?

http://www.daystarfilters.com/COMBOQuark.shtml

[baggywrinkle]

Been looking at these but two version each $995? So which one do you buy and does either do both jobs?

I had also heard about quality issues....

[Peter Drew]

Most Daystar Ha systems require a ~F30 arrangement to operate at best, this is why the original Quark incorporates a X4.2 Barlow for use with the popular short focus refractors.

The latest offering has been designed with a lesser power Barlow to enable the users of long FL telescopes such as SCT's and Mak's to join in. I'm not sure about the differentiation between SCT's and Mak's regarding full aperture use, several Mak instruments have a separate secondary which might suffer without aperture reduction, a full aperture ERF would cost £££££!. From my experience with the original Chromosphere and Prominence Quarks I'm sure that the former would be the best buy overall.     

[michael.h.f.wilkinson]

These do not contain a tele-centric and are all intended for use in combination with an off-axis ERF. This will produce F/30 in most SCTs and Maks. I do not really see the point. An off-axis ERF is so expensive it is cheaper to buy an ST80 and get a regular Quark. In my C8 I only get about 65mm aperture from an off-axis ERF, so the ST80+Quark solution is WAY cheaper and gets me more aperture

[Luke]

I have seen before and have I got it right that you have to use a reduced (off axis) aperture of the SCT? What kind of aperture are we talking? If you are losing a lot of aperture, has this got any benefit over using a 100mm or 120mm frac?

A thought crossed my mind, with the 2x Barlow, could you do something crazy like use a frac, stick a 0.5x reducer in this 2x Quark, and put that inside a regular Quark? Regular Quark is first in the light path. I just wondered if it can be used as a zero power way to double stack a Quark.

Probably not

Maybe two Chromos would be too dark but what about two Prominences? I am out of my depth here, I just wonder about double stacking to reduce photospheric leakage?