Quark Full Disc at F6.3
Posted 25 August 2019 - 07:14 AM
Posted 25 August 2019 - 08:09 AM
Make sure you use the focal reducer after the Quark. The Quark works better at higher focal ratios, more contrast on surface features. I use a cheap .5x focal reducer mostly for imaging. A nice alternative scope is the Orion ST80. I can get a full disk with a 25mm eyepiece. It's great for proms at its native focal ratio and comes with an aperature mask for more details of the surface.
Posted 25 August 2019 - 08:21 AM
I have a Quark chromosphere and at the moment have it running on an F8.5 scope and get just over a quarter disc at the ep. I’m trying to source a reducer to reduce scope down to F6.3 and wanted to know how much of the suns disc will I get at the ep with this up grade to determine if it’s worth doing or buying a new scope. Anyone have any experience with a Quark at about f/6?
I would highly suggest that for similar cost to buying reducers, consider just adding a small 400mm focal length refractor to your kit and use that, full disc view without any special anything. A Meade Adventure Scope or similar (ST80 basically) will provide a full disc FOV with a Quark with a 25mm eyepiece. Anything near that 400~500mm range will work for this.
- PatrickVt likes this
Posted 25 August 2019 - 08:26 AM
Posted 25 August 2019 - 08:27 AM
Posted 25 August 2019 - 08:46 AM
I have an option to buy a stellarvue nighthawk 80mm f7. Would that do a better job?
That won't produce full discs either. Nice scope though!
400~450mm focal length with the Quark and a 25~32mm eyepiece provides full disc FOV. But really needs to be closer to the 400mm side of things.
I'm not sure where you can buy from in Australia, but I would again look to the 72~80mm F5~F6 scopes and source one with a strong focuser or one you can replace the focuser on. An inexpensive achromat will do fine here (ST80, etc). You can probably still get away with a 1.25" focuser, if it's strong.
Here's an 80mm F5 (ST80) with a 2" focuser handling a Quark and all that. Full disc FOV with room to spare.
Edited by MalVeauX, 25 August 2019 - 08:49 AM.
- paulsky likes this
Posted 28 August 2019 - 03:12 AM
Just for the record, the Quark works well at f/6.3, at least when that is the native focal ratio of the scope (130mm f/6.3). I am not sure what effect the focal reducer will produce. If f/8.5 gives you a quarter disc, then I guess f/6.3 will give you about a third of a disc. Better to get an inexpensive small scope, as noted above.
Posted 28 August 2019 - 05:57 AM
I’ll be giving it a go at 765mm and 640mm focal lengths. I’ll see how these two scopes work out. If I can get a good chunk of the disc in the fov I’ll be happy even if it’s not the entire disc. For reference at 1020mm with a 36mm ep this is the view. Can’t get anymore tighter from here with the proposed focal lengths.
Posted 31 August 2019 - 11:49 PM