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Daystar Quark Chromosphere Review – A New Era in Amateur Solar Astronomy? Until recently, it’s been very expensive if you want to view or image the Sun in the hydrogen-alpha wavelength using a relatively large aperture such as 100mm. For example, a Lunt 100 dedicated h-alpha scope with B1800 blocking filter and Feathertouch focuser is likely to cost in excess of £7,000. In 2014, things suddenly changed. Daystar Instruments, who have over 40 years of experience in solar filters, released a new product, the Quark. Costing less than £1,000, this new type of device can be used with many refractors, turning them into h-alpha solar telescopes. Enter the Quark The Quark works in a different way to the regular dedicated h-alpha telescope. Daystar refers to the Quark as being the world’s first h-alpha “eyepiece.” It’s not really an eyepiece. Typically, you place it between the diagonal and your actual eyepiece or camera. The Quark has a professional look and feel with an aluminium housing. It comes with a mains unit for power. I prefer to use a USB battery pack and longer cable. Inside the Quark is a 4.3x telecentric Barlow. This helps to ensure that light passing though the Quark is reasonably parallel, which is required for good performance. The Quark requires power and about ten minutes or so to warm up. This is because the tuning of the Quark’s etalon is controlled by the heating of an internal cavity. For energy refection, many refractors can be used without the need for an expensive front energy rejection filter (ERF). The manual states that if your scope is under about 120mm of aperture, you can use a compatible UV/IR cut filter in front of the diagonal instead of using a front ERF. However, a front ERF must be used instead of the UV/IR cut for telescopes with an integrated rear field flattener or Petzval lens or if over about 120mm. See the Quark manual for more information and check with Daystar if you’re not sure what you need. Quark Basics The Quark unit I am reviewing is designed for use with refactors in the range F4- F9. Daystar now also sells a Combo Quark for off-axis use with SCTs. The Quark comes in two flavours, both priced £899 at time of writing: ‘Chromosphere’ and ‘Prominence.’ The Chromosphere version (the one I am reviewing) is specified to have a bandpass of 0.3 to 0.5 Angstroms, while the Prominence is 0.6 to 0.8 Angstroms. In short, the Chromosphere is best for surface detail and gives more contrast on the disc, the Prominence is best for prominences, but there is crossover between the two. Depending on your setup, it is possible to use a 0.5x reducer with the Quark to bring down the focal length if you wish. Because of the integrated Barlow, there is plenty of backfocus available. The Quark comes with a main supply included. I recommend using a rechargeable USB battery and long cable instead for greater convenience. Daystar sells a battery pack as an extra, though some users have noted that it bears a striking resemblance to much a cheaper battery pack available from Amazon! Eyepieces are another consideration. Because of the Quark’s integrated Barlow, you need long focal length eyepieces. Daystar recommends Tele Vue Plossls, specifically the 25mm, 32mm and 40mm. However, some Quark users have reported excellent results with Vixen SLV eyepieces. The integrated Barlow can also affect how much of the Sun you can see in the field of view. Full disc viewing is possible with refractors up to about 450mm focal length. Lastly, the Quark has an integrated 12mm blocking filter and offers 21mm of clear aperture filter. Getting Up and Running The Quark may be relatively cheap, but it looks professional, with its anodised red and black aluminium housing. The 1.25” eyepiece holder includes a brass compression ring. This is a nice touch though in practice I have found the compression ring to be sticky. There were a few worrying moments when my camera or eyepiece snagged on an edge and I was concerned that I might drop it! Fortunately, the eyepiece holder unscrews easily and can be replaced. First Light Optics sells an adapter for the Quark that enables T-threaded accessories to be fitted. Using one of these adapters, I swapped the Quark’s eyepiece barrel for a Baader ClickLock 1.25-inch eyepiece holder. Much better! The Quark has a combined 1.25” and 2” nosepiece, so you can use it as is with a 1.25” or 2” diagonal. If you use it as 2”, don’t forget to take the dust cap off the 1.25” nosepiece, or you may see smoke rising out of your Quark! First Light with Al Nagler’s Briefcase Telescope I decided to be cautious and gradually step up in aperture. First up was my smallest scope, the Tele Vue 60. Its focal length is just 360mm, so this looked a good option for full disc viewing with the Quark with room to spare. To set up the Quark, I placed a UV/IR cut on the front of the 1.25” diagonal, slotted the Quark in the diagonal, hooked up my battery pack, and waited for the Quark’s LED to turn from yellow to green. After about 12 minutes, it was green for Go! Unfortunately, there was lots of patchy cloud around and conditions were not ideal, so it was hard to tell just how well the Quark was performing. I found that turning the tuning knob from central to a few other positions in clockwise direction improved the view. When I changed the tuning, the Quark LED turned yellow and it took a few minutes or so until the LED turned green again to indicate that tuning had been reached. I was able to carry on observing while the tuning changed, the view was stable and I couldn’t tell anything was changing, it was too gradual for my eye to detect any change in real time. Another reason why it was hard to judge the view was that I had no towel with me! With the Tele Vue 32mm eyepiece I was using, I had to have a gap between my eye and the eyepiece due to the eyepiece’s very long eye relief - I later bought an eyeguard extender for this eyepiece to make it a snugger fit, and bought two extenders for the 40mm! Second Light - Throwing in the Towel I was better prepared for the Quark’s second light. This time I had a towel at the ready and a little more aperture to bring to the party: the Tele Vue 85. The first view was glorious. The spicules at the edge of the Sun were much more clearly defined than with my Solar Max 60. Contrast was better than I had expected. I was very used to views with both single stacked and double stacked SolarMax 60’s and without doing a direct comparison, the contrast of the disc felt middle of the road – more contrast than with my single stack SM60, but not quite as much as with the double stack. Also the swirls and whirls around active regions showed considerably more detail than I have ever seen with a 60mm scope. Proms appeared to show a finer structure than usual, a little bit like using a bigger dob to observe galaxies in Leo. The Quark was making the extra aperture of the TV85 count. And what really struck me was that there was no obvious sweet spot whatsoever. With the SolarMax 60, there is a considerable sweet spot and often I nudge proms towards the centre of the view for a better look. With the Quark, proms looked just as good towards the edge of the view. For the £795 I had paid for the Quark, I was impressed. It was not all good, though. Unfortunately, there were distracting flaws in the eyepiece view: in particular, a bright spot and two fold-like marks that moved with the view. The unit would have to be returned. The retailer, SCS Astro, kindly allowed me to carry on using this Quark for some weeks while I waited for a replacement. This was terrific news: this Quark worked very well for imaging, the flaws did not show up on the small camera chip. Thank you, SCS Astro! Plossls at Dawn - Quark and TV60 Versus Solar Max 60 Single and Double Stack The big deal for me about the Quark is that it makes larger aperture solar h alpha more affordable. However, the reality is that some folks will be deciding between a smaller dedicated h alpha scope, like the Lunt 50 or a second-hand SolarMax 60, versus the Quark. They are a similar price. So, can a Quark take on a dedicated scope at the same aperture, never mind in the larger scopes? I had two SolarMax 60’s at the ready to find out. One was single stacked (SM60 SS), the other was double stacked (SM60 DS). I grabbed some Plossls for the Quark, and Radians for the SM60’s. First up to challenge the Quark was the SM60 DS. The SM60 DS landed an instant blow to the Quark – it gave better contrast. Very nice indeed. There was a huge filament dominating the disc on this day, and it was gloriously dark against the surrounding brighter parts of the disc in the SM60. The filament jumped out that little bit more. Also, plage showed more contrast with the SM60 DS. Another win for the SM60 DS is that it did not show the double limb, whereas the Quark did, which is to be expected as the double limb shows in single stack systems (including my SM60 SS). The double limb is caused by light from the photosphere leaking through. Personally I don’t mind it, but a purist may prefer a double stack system that eliminates it. The Quark soon bounced back and jabbed the SM60 DS firmly in the eye. The Quark had no obvious sweet spot. The full disc view with the Quark shows sharp, well-defined proms and tiny spicules to the edge of the field of view. As mentioned before, the SM60 has a considerable sweet spot and proms looks best more central. Over the months I greatly enjoyed the impact of full disc views especially on days with lots of proms where detail is so good all across the entire view. All in all, I couldn’t split the Quark and TV60 vs SM60 DS. It was a case of no obvious sweet spot vs better disc contrast. Next up was my trusty SM60 SS, which I had used a great deal for grab and go. Part of me was rooting for my faithful companion. Round one was contrast, and it was close. Too close to call. In terms of fine detail, the Quark had the edge, I could see a little more structure with it. And then there was the sweet spot again. The Quark was the champ here, with its lack of any obvious sweet spot. The final bell rang, it was a win on points for the Quark, the lack of a sweet spot had carried it to victory. NOTE: Over the coming months, one thing puzzled me about the Quark: In my other telescopes, contrast seemed significantly better than with the TV60. I eventually tried using the Quark and TV60 with the Quark in a straight through configuration (UV/IR cut in front of the Quark) with the diagonal after the Quark. This really improved the contrast, and at higher magnification, I could see much finer detail in active regions than I have ever seen with the SolarMax 60. Wow! If the Quark is not lined up well with the light path, this can lower the performance of the filter. If your Quark is not performing well, try using another diagonal if you have one (don’t forget the UV/IR cut if you are using one). If trying a straight through configuration, be sure to check the advice from Daystar for safe usage. Time for the Big Gun - Equinox 120 At last it was time to use the Quark with the scope I was most looking forward to testing it with: the Equinox 120. I felt that this was about the largest aperture I could use with the Quark without having to buy a very expensive front energy rejection filter that would roughly double the cost. I used an Astronomik 2 inch UV/IR cut on the front of the diagonal. The first thing that struck me about the initial view was: wow, that is a small piece of the Sun I am looking at! Secondly, conditions were great, I wish I had set up for imaging! Spicules were that little bit crisper and clearer than with the Tele Vue 85. Smaller proms revealed much more "character" than at 60mm. In particular, there was a very small looping prom on display. I could see the separation from the disc clearly as it arched over the limb. Smaller proms like these typically show little detail at 60mm and it feels like there’s a gap and a loop, but it’s not clear to see. With the 120mm it was crips and beautiful! Swirls of detail around the active regions came more alive than at 60mm, filaments showed finer structure and complexity at the higher magnifications. There was, quite simply, detail everywhere I looked. I was greatly impressed. One of the downsides of the Quark versus a dedicated scope like the Lunt 100 is that you cannot view the whole disc in one go in larger scopes. Although it’s possible to use a reducer with eyepieces to view the Sun at a lower power, I didn’t feel the need anyway. At lower mag I could not see as much fine detail, and fine detail was why I was putting the Quark in a 120mm scope in the first place. I wouldn’t be pining to see the full lunar disc if using a 14 inch SCT. Quark and big scope is about close-ups. I would be using the Quark with my TV60 for grab and go, so I would get plenty of low power full disc then. Life with Quark Since these early views in 2014, I have used the Quark many times in four different telescopes. Just like white light with a Herschel wedge, I find it convenient to be able to use the Quark in different scopes. The Quark certainly works as a grab and go for me. On an unusually sunny holiday I managed 17 straight days of using the Quark and TV60. I used a mini giro mount and tended to power up the Quark indoors while having breakfast so that it was ready to use afterwards. Perhaps a fast 80mm would make more sense, to still allow full disc and to reveal finer detail at higher magnifications, but I love the portability and character of the little scope and for me grab and go is about fun and enjoyment, not the best view. Also, the sleek black TV60 does not draw attention to itself, unlike my old gold SolarMax 60! My favourite scope for imaging is the Equinox 120. I normally use a 1.25” 0.5x reducer, a cheap £20 or so buy from Telescope House. My favourite scope for observing in the Skywatcher ED100 DS-Pro. I find it nearly matches the 120mm for detail, yet is comfortably ahead in detail than my 85mm scope. It’s also nicer to use on my giro scope than the 120, being considerably lighter. My Tele Vue 85 also gets Quark time. I tend to use it as a compromise scope. If I’m imaging and it’s a bit windy, I will drop down to it from the 120mm. Or if I just want a quick view, sometimes I will grab the 85 instead of the 100, as it’s a far smaller scope and the view is certainly a step up at higher magnifications than with my Tele Vue 60. When I first heard about the Quark, my two main concerns were the integrated 4.3x Barlow and the need for power. In practice, I haven’t found these to be much of an issue. A 0.5x Barlow tames the focal length for my needs. I could probably push the Quark more than I do, I was impressed in one session when I forgot to put the reducer on my ASI174 and the view on screen looked very good and do-able. I also like that the Quark’s Barlow is inside the Quark, protected from the dust that my regular Barlows always seem to attract! I found the power requirement okay, and a small price to pay considering the relatively low cost of the Quark. A portable battery pack means I can power up the Quark indoors or while I am getting out the mount etc. I use a long cable and then run this up the telescope tube and down the side of the mount, so it doesn’t tend to get in the way. The warm up time of ten minutes or so makes no difference to my imaging with the Equinox 120. It takes me at least that long to get set up (rough alignment, setting the time etc. on the handset, moving to the Sun, getting the camera ready, and so on). The time it takes for the Quark to reach a new tuning also hasn’t really troubled me. I have used several Quarks and once I have found a tuning that I like, I just keep it on that. If you are a more advanced user, perhaps this is more of an issue if you want different tunings such as to show Ellerman Bombs. There has been a lot of talk since the Quark came out about the bigger scopes being more demanding on the seeing. For visual, I normally use my ED100 and it’s fine, it shows far more close up detail than with the 60mm scope. If the seeing conditions are very choppy, which is fairly rare (I tend to do mornings when conditions are usually better), I have no great wish to see it at 60mm either, I prefer leave it a while to see if things settle. Out of my four Tele Vue Plossls, my favourite to use with the Quark in all four scopes is the 32mm. I am content just using this eyepiece. Now and again I like to sneak in closer with the 20mm or 25mm, but really, things look good and detailed already with the 32mm, I could get by with this one eyepiece alone. However, I would consider the Vixen SLV instead if buying again following some reports on excellent performance from other Quark users. Quark Issues Unfortunately, I have experienced a number of issues with the Quark. In total, I purchased four Quarks from three different retailers and today I have two out of the total of eight Quarks that I have used. Here is a brief summary of how I got on with them. Quark 1: Performed excellently for imaging but showed defects in eyepiece view: small bright spot and two dark fold-like marks in eyepiece view. Returned for replacement. Quark 2: Replacement for Quark 1. Large scratch-like mark in eyepiece view. Returned for replacement. Quark 3: New, second purchase. Wanted two Quarks, plus cover in case of further problems with first Quark purchase. Quark gave very uneven illumination (see small flat image below) and loss of detail over large parts of eyepiece view. Was part of a problem batch apparently. Returned for refund. Quark 4: Replacement for Quark 2. Performed fine for imaging, accepted. I still own this Quark. Quark 5: New, third purchase, still wanted second Quark. Accepted this Quark, to use for imaging. Quark developed fault within 12 months (view looked somewhat like white light). Returned for warranty repair/replacement. Quark 6: Wanted third Quark, for wife’s use, mostly visual. Quark gave excessive glow in eyepiece view with inferior views of proms. Returned for replacement. Quark 7: Replacement for Quark 6. Performed well, clean view, accepted. Quark 8: Warranty repair/replacement for Quark 5. Appeared to be replacement (different barrel). Many splotches over much of eyepiece view. Returned for refund as agreed by retailer. Verdict The Quark is a brilliant device that can dramatically cut the cost of viewing or imaging the Sun in hydrogen alpha in larger scopes than 50/60mm, and it offers an interesting alternative even if used in smaller scopes. In my experience it gives reasonable contrast, though not quite as much as a double stacked dedicated scope. The Quark shows no obvious sweet spot. At apertures of around 100-120mm, the Quark gives remarkably detailed views at higher magnifications. I highly recommend apertures of 100mm or more. For visual, I found the Skywatcher ED100 DS-Pro to be a superb match. Although the Quark may look less flexible than a dedicated h alpha scope because of its integrated Barlow, you can tame the focal length to some degree using a 0.5x reducer. The Quark gains some flexibility from being able to be used in different telescopes, such as 60mm for full disc (with my setup, full disc imaging in four tiles versus single tile for SolarMax 60) or 100mm for close-ups. If you want to travel light, it can be a plus that you can use the same telescope for hydrogen alpha (Quark), white light (Herschel wedge) and regular astronomy. The Quark can look like a no-brainer if you want to use a large telescope around the 100-120mm mark and your funds do not stretch to the likes of the Lunt 100. However, all things considered, with a heavy heart I cannot recommend the Quark. I have experienced a number of issues. From a total of eight Quarks used, I now have only two of them. I would not buy a Quark now. I would be thinking, okay, if I buy from a good retailer, I can return the unit promptly if it does not meet my reasonable expectation. But what if I am happy with it, accept it, and it breaks after say ten months? What if I send it back to the USA, wait some weeks for a repair/replacement, and it is replaced with a Quark that performs very differently to the one I had accepted, and it shows distracting flaws in the eyepiece view? This has already happened to me once - see Quark 5 and Quark 8 in Quark Issues, above. I requested a refund as I considered that the repair/replacement had failed. I understand that another replacement was offered by Daystar. The retailer, SCS Astro – who have been very supportive throughout – kindly agreed to a full refund. Thank you, SCS Astro! While the close-up views at 100-120mm can be intoxicating, I recall that I had no problems with my two SolarMax 60’s. Next time out, I intend to take a very close look at the Lunt 50. It is returning some excellent full disc images and I have enjoyed a number of views though Lunt telescopes. Perhaps less is more sometimes when it comes to aperture. NOTE: You can read about SCS Astro’s experiences with the Quark and customer issues here: http://www.scsastro.co.uk/ Quark Cons Less contrast than a double-stacked dedicated solar h-alpha scope. Full disc not visible in scopes above about 450mm focal length. Integrated 4.3x Barlow ramps up the focal length for imaging, though depending on camera chip, you can use a 0.5x reducer. Eyepiece selection is more fussy, 25-40mm Tele Vue Plossls are recommended. 2” eyepieces do not fit by default, though a replacement 2” eyepiece holder is available. Power is required, in practice I found this to be less hassle than it sounds when using a battery pack and long cable instead of the included mains unit. A battery pack is available from Daystar though be wary of the high price compared to alternatives. Quark needs to be powered for about ten minutes or so before use. Quark needs a few minutes to change to a new tuning. Quark Pros Costs far less than a dedicated 100mm scope. No obvious sweet spot. Use the same scope for white light/regular astronomy as well - ideal for travelling light. Use different scopes to match your current needs, e.g. 80mm for grab and go, 120mm for close up imaging. The integrated 4.3x Barlow is shielded from dust. Quark Images