Observe and photograph sunspots using your instrument equipped with this SolarLite ND 5 front filter with a metal frame. For an outer diameter of the tube or dew shield ranging from 80 to 89 mm; ensure the filter is securely attached and check it before each observation session.
Available by special order — 2-week lead time
CHF 95.18incl. Swiss VAT
Part Number WLF90
Will be ordered for you
Timeframe: 10 days to 3 weeks
Estimated shipping: Between November 20 and 25, 2026
The DayStar WLF90 is a full-aperture solar filter that combines a film SolarLite of Thousand Oaks to a metal frame. It is attached to the front of the instrument and is suitable for tubes or anti-fog screens whose The outer diameter measures between 80 and 89 mm. This mounting size is the first thing to check before choosing a filter.
Designed for observing and imaging the Sun in white light, it renders the solar disk in an orange-yellow hue. Its ND 5 optical density filter blocks 99.999 % of the light, according to the manufacturer’s data. The rigid frame provides support for the film, while three knurled screws made of glass-fiber-reinforced nylon secure the assembly to the instrument.
The designation WLF90 refers to a filter with a 90 mm inner diameter; it does not mean that this filter is suitable for all telescopes with a 90 mm aperture. Measure the outer diameter of the tube, the dew shield, or the objective lens at the point where the filter will be installed. For this model, DayStar specifies a range of 80 to 89 mm.
The WLF90 allows you to begin solar observation using your existing equipment, provided you have a compatible and secure front mount. It is an affordable solution for tracking the evolution of sunspots and starting to photograph the solar disk.
To explore solar prominences and the chromosphere next, check out the Solar Scout SS60DS H-alpha, a pair of specialized solar viewing glasses. The two approaches reveal different phenomena and each requires its own filtration setup. To prepare for a club session or a supervised school activity, Contact Deep Space Astronomy.
Solar observation requires a secure setup. Before each use, check the condition of the filter and make sure it is securely attached. Do not use a torn or punctured filter, and never point an unprotected instrument toward the Sun. Follow the manufacturer’s safety instructions.
This white light filter does not replace an ERF energy rejection filter for a DayStar H-alpha system or a Quark. It also belongs to a different line than the DayStar ULF foldable filters: their dimensions and mounting are not interchangeable.
| Brand | DayStar Filters |
|---|---|
| Manufacturer reference | WLF90 |
| Type | White-light solar filter for the front |
| Filter material | Thousand Oaks SolarLite Polymer Film |
| Optical density | ND 5 |
| Announced Light Output | 99,999 % |
| Mount | Metal, nominal inside diameter of 90 mm |
| Compatible outer diameter | 80 to 89 mm |
| Mounting | Three knurled screws made of glass-fiber-reinforced nylon |
| Solar Image Tint | Orange-yellow |
A WLF90 solar filter with SolarLite film mounted in its metal housing and secured with three screws. Observation instrument not included.
Official promotional photo of the WLF line; the diameter shown may vary.
