The Quark Chromosphere version shows both prominences and chromosphere detail and is the "go to" Hydrogen Alpha solar observing device with your refractor telescope. It's currently the most afforable way to get into solar Hydrogen Alpha observing or imaging!
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.
For best results we recommend a suitable ERF (Energy Rejection Filter) is used before the Quark filter. This keeps the bandwidth from drifting during a solar observing or imaging session. For scopes of 100mm aperture or less, this can be screwed into the front of the diagonal or extension tube. For scopes larger than 100mm we recommend putting the ERF on the front of the telescope for best results as it avoids heat turbulence inside the scope tube and protects the interior of your telescope from damage if the sun goes off-centre whilst you are aligning it. Please note the Quark is not suitable for for reflecting telescopes. Only refractors should be used.
Recommended refractors & ERF combinations: *
- Altair 60EDF F6 Triplet (can be used without an ERF, but better with 2" ERF on diagonal)
- Starwave 70mm ED Triplet (can be used without an ERF, but better with 2" ERF on diagonal)
- Altair 72EDF F6 Doublet (better with 2" ERF on diagonal)
- Starwave 80ED F7 Doublet (better with 2" ERF on diagonal)
- Altair 80mm ED Triplet APO (good with 2" ERF on diagonal, even better with front ERF)
- Starwave 102ED F7 Doublet (requires 2" ERF on diagonal, better with front ERF)
- Altair Wave Series 102mm ED Triplet APO (requires 2" ERF on diagonal, better with front ERF)
- Altair Wave Series 115mm ED Triplet APO (requires front mounted ERF to take best advantage of the optics, 2" ERF on diagonal is not considered safe and can overheat, contact us for custom ERF)
- Altair Wave Series 130mm ED Triplet APO (requires front mounted ERF for safety and best optical quality, contact us for custom ERF)
- Starwave 152mm Achromat (requires front mounted ERF for safety and best optical quality, contact us for custom ERF)
- 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.
Energy Rejection Filter Q&A:
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 EQ Mount or iOptron Minitower AZ, 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. The ERF should ideally have a surface flatness of 1/4 wave at the very least. 6-8th wave surface accuracy is better for fine detail. ERFs can be single band (Ha only) or dual-band (Ha and Calcium). We can provide high quality ERFs to suit our refractors from 115mm upwards.
Q: Why use a front mounted ERF?
A: There are 2 main reasons for using a front mounted ERF:
#1 Safety and longevity of your equipment. Internally DIY mounted ERF filters work by reflecting the unwanted radiation (in this case mainly heat) and they can reflect an intense focused 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 cigarette in front of the objective lens, with an internally mounted ERF set too close to the objective.
#2 Image quality. All ERF filters do absorb some energy, as no filter can be perfect, and the radiation of this heat occurs 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.
Q: I have read about hobbyists using a smaller "internally mounted" ERF of smaller aperture, part-way up the telescope tube to save money. Does this work, and what are the trade-offs?
A: An "internal" ERF works for smaller apertures up to about 4", but for larger apertures, the image quality cannot ever be as good as with a front mounted ERF which stops energy entering the telescope tube in the first place. 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. Refractors over 4" seem to be more affected by tube currents and by the time you get to 6" the image is noticeably degraded. Another reason to have a front ERF is a safety one. We have had customers with a burnt tube, melted UVIR cut filters, and also melted Narrowband Ha pre-filters. 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. The closer it is to the lens, the worse the degradation will be. 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 an "extra lens" is placed, the more alterations you are introducing into the optical system taking it further away from design parameters. Any flat lens placed inside a refractor light cone behind the pupil (front objective) will cause increased spherical aberration which reduces the ability of the telescope to resolve fine detail. The bottom line is that for scopes under 100mm you can use a good quality 2" ERF filter in front of the diagonal, but for best results with scopes larger than 100mm, a front ERF is recommended.