Daystar Instruments QUARK* Hydrogen Alpha "Eyepiece" (Chromosphere Version)
Product code: DSZ4C
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Daystar Instruments QUARK* Hydrogen Alpha "Eyepiece" (Chromosphere Version)Daystar Quark H-Alpha Eyepiece (Chromosphere Version)
This new, All-In-One design marries high quality components of a telecentric barlow, adapters, snouts and Daystar hydrogen alpha filter into one simple assembly. Through design efficiency and optimization, now users can enjoy the known high quality optics of DayStar* at an affordable price.
A suitable ERF (Energy Rejection Filter) should be used before the filter. This is screwed into the front of the diagonal to stop any UV or IR radiation before it gets to the Quark. Strictly speaking under 80mm of aperture an ERF isn't required, but we still recommend it.*
The QUARK contains a custom Daystar Instruments 4.2X telecentric Barlow lens fully optimized in coatings and optical design specifically for the Hydrogen Alpha wavelength. This highly specialized telecentric lens offers superior field flatness.
Exact filter bandpass will vary based on final telescope application, so QUARK assemblies are qualified to show either prominence or surface (chromosphere). No specific FWHM bandpass is designated.
Now observers can buy a filter based on their desired observing goals instead of their budget. Choose prominences and surface (Chromosphere) detail.
The fully optimized design eliminates the need for any adapters. It's all combined in one lightweight eyepiece sized device. The new, compact design configuration eliminates unnecessary components, weight and associated costs. We even reduced power consumption, so the Quark can now operate all day off a small, palm-sized optional battery pack. Baffles have been added to increase contrast and AR coatings are optimized for the 656nm wavelength.
- 1.25" or 2.0" combo eyepiece snouts with safety indent slot directly into your diagonal
- Standard 1.25 eyepiece drawtube output with optional 2" and SCT accessories available.
- Brass compression ring to protect eyepiece.
- Uses USB power, 5v 1.5amp
- Includes 90-240VAC wall adapter with international plug adapters.
- Tuning knob allows wing shifting +/- 0.5Å with detents at every 0.1Å
- LED indicator for power, warming, ready, fault
- 5 year manufacturer warranty.
- Optional 8-hour battery pack available. (contact us)
- Solar powered power supply. (contact us)
- Integrated, fully baffled 2 element telecentric 4.2X barlow optimized for 656nm
- Integrated 12mm blocking filter
- 21mm clear filter aperture
- Best performance with F/4 - F/8 refractors
- Full disk viewing possible on refractors up to ~450mm focal length refractors
- No aperture limitations. May be used on larger refractors for higher magnification views (with ERF*)
- Ships in convenient Twist-Case for safe, dust-free storage.
- Not suited for off-axis application.
Q: Do I need a 2" ERF (Energy Rejection Filter) on the diagonal mirror for telescopes under 80m?
A: Although not strictly required for apertures under 80mm, for telescopes up to around 100mm we recommend using an enegrgy rejection solution such as a UV IR filter in front of the diagonal mirror. For any solar tracking system such as the Sky-Watcher Solarquest, an ERF solution is required because the sun stays in the field of view for a long time. You can order a 1.25" or 2" UV/IR filter in the dropdown menu depending on your diagonal type.
Q: What kind of ERF do I need for telescopes above 115mm?
A: For any telescope above 115mm you really should get a front-mounted ERF. A 115mm refractor will perform better with a front-mounted ERF than with a 2" ERF filter and it is safer.
Q: Why use a front mounted ERF?
A: There are 2 main reasons for using a front mounted ERF:
- Safety and longevity of your Quark. Internally DIY mounted ERF filters work by reflecting the unwanted radition (in this case mainly heat) and they can reflect an intense focussed beam of energy back up the telescope tube. If slightly off-axis, this can set fire to the inside of your telescope tube - usually when it strikes the edge of the baffles. (Baffles are circular rings inside most telescope tubes which block stray light to improve contrast). Also it can direct that energy out of the tube on-axis. You can light a cigarrette in front of the objective lens, with an internally mounted ERF set too close to the objective.
- Image quality. All ERF filters do aborb some energy, as no filter can be perfect, and the radiation of this heat occurrs by convection and also dissipates into the surrounding metal via the filter holder. This excess heat can cause heat currents inside the tube which reduces image quality.
A: An internal ERF larger than 2" and inserted into the telescope tube definitely works, however results vary significantly, and the image quality isn't as good as with a front mounted ERF. There are 3 main reasons for this:
- Tube currents. A front mounted ERF keeps the whole telescope cool, so there are less heat currents generated inside the tube to degrade the image. (Heat currents are more of a problem as aperture increases). Larger aperture refractors seem to be more affected by tube currents are are best kept as close to ambient temperature as possible.
- Heat buildup and your Quark. ERFs are less efficient when light strikes them at an angle like in a light cone created by a refractor. This means that internally mounted ERFs are invariably less efficient than external ones which are dealing with parallel rays from the sun, instead of the converging rays found behind a lens. That means your Quark or Quantum can overheat and go off-band too, degrading the image quality. Why risk damaging your Quark or Quantum filter? Already we have had a burnt tube, damaged Quark, also melted narrowband Ha pre-filters.
- Optical quality. A large, (say 80-100mm) internally mounted ERF has to have relatively thick glass to remain flat during the coating process (because the coating process causes tension on the glass). Any piece of glass behind the objective (front) lens of the telescope is in fact considered a "lens", and must be treated as part of the telescope's lens system with resulting impact on the final image. It's worth bearing in mind that refractors are not designed with an extra "mystery" lens at an arbitrary distance from the front lens inside them. They are precisely figured to work as one unit, and the further towards the objective the "extra lens" is placed, the more alterations you are introducing into to the optical system. Any flat lens placed inside a refractor's light cone behind the pupil (front objective) will cause increased spherical aberration which reduces the ability of the telescope to resolve fine detail. This is why, quite often, it is better to buy a small ERF, and put it on the front of your telescope before the pupil/objective lens, even though the overall aperture is reduced. It is worth remembering that Ha solar filters work better at longer focal ratios, therefore you could even be improving your filter performance at the smaller aperture. For example, we have an existing customer who bought and tried an 100mm internally mounted ERF with their 6" refractor, and who, when placing it at the front of the same telescope, experienced an immediate improvement in contrast and sharpness. That is why an internally mounted ERF with a larger aperture of 115mm plus could be a false economy. To put it another way, would you make your nice ED doublet or achromat into an "instant triplet" by adding a flat piece of glass into the optical system?
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