Quark Eyepiece

[Spacedout]

Hello, I am currently preparing my letter to Santa and I'm thinking considering last year's letter, a Lunt 152 would be pushing my luck!  Therefore, I have been looking at the Quark Eyepiece as a safer bet  My question is, does anyone here have any experience with this eyepiece and if so would it be a good starting point into the world of Solar viewing/imaging?  Also which of the two types would be best to start with, Chromosphere or Prominence?     I have an Equinox Ed80 to put it on.

Hope someone can help.

Many thanks

Karl

[Peter Drew]

Hello Karl. I've used a Chromosphere  Quark on an Equinox 80mm and the results are superb, particularly with a binoviewer. It shows all Ha solar features very well, the prominence version was disappointing, the prominences were well seen as were the spicules but the image brightness seemed to swamp any surface detail. IMO the chromosphere version is by far the best choice.    

[Luke]

Hi Karl,

I have used a Quark for a good few months now, for visual and imaging. Santa wouldn't get me the Lunt 152 either

I would say, yes, the Quark and 80mm scope is a good starting point for solar viewing and imaging. I use my Quark with 60, 85, 100 and 120mm scopes - the 100 and 120 are the Skywatcher DS-Pro and Equinox respectively, they work really well with the Quark.

For the price, I find the Quark amazing. A double stacked SolarMax 60 costs over £2k and for less than that you could buy a Skywatcher 100 DS-Pro, Quark and a few accessories and the detail/resolution would be far superior in the ED100. I'd also expect your 80mm to have the edge with detail. Where the SM60 double stack does win visually, is that it has more disc contrast, which is a very nice plus, though I find contrast fine with my Quark, not a problem - though I would be concerned that a Prominence version, which I have not used yet, may be getting a little light for disc contrast for my eyes.

However, it's not quite as easy as that as the SolarMax 60/Lunt 50 do have some advantages. e.g. no warm up time (the Quark needs ten or so minutes to heat up) and a shorter focal length (the Quark has an integrated 4.3x Barlow, though you can use a 0.5x reducer with it to make it closer to 2x) - with my video camera I can image the full disc in one tile with my SolarMax 60 but need four tiles with the Quark and my 60mm scope (using the 0.5x reducer). Not a deal breaker for me but something to consider. With my ED100, I can't see the full solar disc even with a 40mm Plossl. Again, not a deal breaker as really the closer up detail is so breathtaking. If I want to see full disc, I can use the Quark with my 60mm scope (360mm native focal length - plenty of space around the disc with 40mm Plossl). I am not sure whether you will be able to view the full disc with the ED80, I wonder if you would just about fit it in?

Since getting the Quark, I am less bothered about seeing the full disc than I thought I would be. The detail is just so rich closer in and I lose that fine detail if seeing the whole disc. I'd say it's a bit like viewing lunar craters. If you were looking at a crater close up with a 14 inch SCT, there is something extra exciting about that versus seeing the full lunar disc with a 60mm frac.

I don't really find imaging with the Quark much more difficult than with my SolarMax 60. In some ways I find it a bit easier to use a larger scope as it's a bit easier to see what the finer details look like when you sharpen.

Regarding warm up time, I don't find it to be much of an issue in practice. If I have my grab and go quick to set up mount, I tend to put the Quark on 10 minutes before I want to use it. Or if I am doing an imaging session with my HEQ5 mount and Equinox 120, I power up the Quark as I start to set the gear up and by the time I am good to go, the Quark is ready. I have missed a couple of times where I spotted a little gap that I did miss due to Quark warm up time, but the view is so good in the 100mm scope I am not that fussed about missing a gap or two with the 60mm scope (remind me I said that when I miss something spectacular! )

I use the same tuning as the last session with the Quark once I am happy with the tuning, so I don't find that much of an issue either, and you can carry on viewing while the tuning changes if you do want to try tweaking it, the view changes very gradually and is stable.

If you are not sure which Quark version to get, I would strongly suggest the Chromosphere version, proms are still very impressive with it, while you get better contrast on the disc.

Some solar nutcases may want both a Quark and a dedicated h-alpha scope longer term, for best of both worlds! I may keep my SM60 for a quick and easy full disc imaging setup or for those late seen gaps, but if only one, it's Quark for me.

[Moonshane]

I am swinging towards the Quark I think and have just bought a 120mm f5 Skywatcher frac both as a wide field scope for use at my school astro club but also with the Quark in mind. Although the stated range of focal ratio is f4-f9 I wonder what the performance would be like with a f11 or f10 refractor. I presume that it would still 'work' but what would be the 'symptoms' of the longer focal ratio? Is it just that in e.g. my 80mm f11 refractor would produce too high a magnification for normal seeing?

[Pete Presland]

is it right there two models one for proms and one for surface detail?

[Stu]

I am swinging towards the Quark I think and have just bought a 120mm f5 Skywatcher frac both as a wide field scope for use at my school astro club but also with the Quark in mind. Although the stated range of focal ratio is f4-f9 I wonder what the performance would be like with a f11 or f10 refractor. I presume that it would still 'work' but what would be the 'symptoms' of the longer focal ratio? Is it just that in e.g. my 80mm f11 refractor would produce too high a magnification for normal seeing?

I think that's right Shane, the only issues would be related to over magnifying due to the focal length. They are apparently working on a x2 barlowed version for longer focal length scopes. As far as I'm aware, these will still need to operate at around f25 to 30 so won't work well in short f/l scopes.

Sent from my iPhone using Tapatalk

[Stu]

is it right there two models one for proms and one for surface detail?

Yes that's right. I have the Chromosphere version as do most people I've heard of, and it shows the prominences very well.

Peter (Drew) has tried both and says the prominences are brighter in the only version but I think the surface detail is swamped by the brightness. Overall I think the Chromosphere version is the better choice.

Sent from my iPhone using Tapatalk

[Stu]

Another point which has been highlighted to me in the whole Apo vs Achro debate in relation to use with the Quark is around the frequency the achro is optimised for.

I'm not an optical expert by any means, but it seems to make sense than most achro scopes are optimised around green focus, whereas Ha is in the red area of the spectrum. I believe dedicated solar Ha scopes are optimised for the red.

The conclusion to this may be that an 80mm apo such as an 80ED would be a better performer with a quark than an 80mm achro like an ST80.

I think the resolution benefits of going to something like a 120 f5 would still be worth it though, if a 120ED is out of budget.

Looking at the brief review on CN comparing the Lunt 50 to a PST, it seems the Lunt is an incremental step better than the PST optically but not dramatically so. Mechanically I'm sure it will be a lovely scope to own and use but the Quark has the potential to deliver much more detailed images in a variety of scopes.

Sent from my iPhone using Tapatalk

[Spacedout]

Wow excellent advice thank you all and Luke above and beyond thank you!  Looks like it's the Chromosphere for me.  I'll be sure to post my results just after Christmas

Thanks again much appreciated.

Karl

[johnno]

Hi Guys, i'd like to ask a question about the Quark, this will be my first adventure into Ha, if I get one i'll be using it with a ED80.  I've heard you only need a ir/uv filter upto 80mm , what I want to know is there a time limit on how long to can keep it on the sun without getting heat build up, i'm planning doing video anywhere upto 3hrs weather permitting or would this be pushing it

thanks John

[Stardust]

I think you'd be fine with the uv/ir on a 80mm, I was tracking the sun with my 127 for a couple of hours with no obvious heat build up.

A 2" filter is recommended placed further up the light cone on the diagonal or a 80mm extension tube

I'm currently testing a Prominence version till my Chromosphere arrives, very impressive prom detail but not so good on the surface, very low contrast  

Here are a couple through the 127 with a QHY5L-IIm on my first session

[davedownsouth]

Quick question, but with the Quark, do you put the diagonal before, or after it?  To me it would seem easier to stick the Quark straight in to the scope and put the diagonal with the visual eyepiece into the other end of the Quark.  Is this how it is done?

[Stardust]

I put the Quark in a 2" diagonal with the filter screwed in the diagonal, if putting the quark in the scope I understand that an 80mm extension tube would be best before it with the filter in that.

[Stu]

As above, I put the Quark in a 2" diagonal, with a 2" UV/IR filter in the front of the diagonal (ie on the sun side). Daystar recommend doing it this way round, not entirely sure why but it's safest to stick with their instructions I think.

Stu

Sent from my iPhone using Tapatalk