Full Aperture (SolarLite) Film Slip-On Solar Filter

$ 69.99

View sunspots and granulation of the surface of the Sun, while protecting both your telescope optics and your eyes with Thousand Oaks full spectrum (white light) SOLAR Filters.

Each filter (whether glass or film) is mounted in a polished friction-fit aluminum cell with a lip that slips over the objective end of the telescope. This prevents the Sun’s heat from building up inside the telescope and possibly damaging the components inside. The filter cell is held snugly in place by 1/32” thick felt strips glued to the inside of the cell lip.

The filters below list the inside diameter (I.D.) of their cell’s lip. They are designed to fit telescopes with an outer diameter no larger than 1/16” smaller than the cell size. (The 1/16” difference is the total thickness of the felt holding the filter cell in place.) If you do not see your brand of telescope and model listed, simply choose the closest filter cell I.D. size that is larger than the outside diameter measurement of your telescope. For example, a 4.25” I.D. filter would fit telescope diameters from 4” to 4-3/16”. Do not choose an I.D. size the same as your telescope outer diameter, since it will be too tight and will not allow room for the felt lining. Ample extra self-adhesive felt is included so you can double or triple the layers of felt for a custom fit.

The SolarLite filters have a 15-year manufacturer’s warranty against flaws in materials and workmanship. If handled with care and common sense, all types can last 20 years to life.

The Sun appears yellow-orange through a Thousand Oaks filter, standing out briskly against a black sky. The filter can be used for both visual and photographic observation, using a camera ISO setting of 100 or higher. Thousand Oaks white light solar filters show only sunspots and convection-cell granulation of the Sun’s surface. A much higher cost hydrogen-alpha line band filter is needed to see flares, spicules, and solar prominences.

Full aperture solar filters use a filter element with a diameter close to or equal to that of the aperture of your telescope itself. The resolution of the filtered image is thereby equal to that of your telescope, showing the most amount of solar detail.

Always remember to install the solar filter before pointing your telescope at the Sun to avoid instant and irreversible damage to your eyesight. Remove or cover the finderscope of your telescope as well, to avoid burning up its crosshair reticle, as well as to prevent accidental eyesight damage.

WHAT SIZE DO I ORDER? The application guide below lists sizes by clear aperture (filter size) and outer cell wall inside diameter (I.D.) The I.D. of the cell slips over and around the O.D. of the telescope tube or lens holder. Please note that the brands and sizes listed are only a guide. Telescope manufacturers sometimes make changes so we strongly recommend the outside diameter of the tube be measured to be sure the correct part number is chosen. Choose the closest outer cell I.D. size larger than the outside diameter measurement of your instrument. Example: part # 4250 (4 1/4") would fit O.D. measurements from 4" to 4 3/16". Do not choose a size the same as your O.D. since it will be too tight and not allow room for a felt lining. Ample felt is included for custom fitting.

ARE THE FILTERS COMPLETELY SAFE? SolarLite filters are completely safe for unlimited visual use. If handled with care all will last a minimum of 20 years to life.

DO THE ALUMINUM CELLS COME WITH THUMB SCREWS? Thumb screws may seem like a good idea, however, our extensive testing found that in most cases it's actually less secure than a felt lining which covers a lot more surface area for a secure friction fit. If the tolerance is within a few thousands of an inch such as with eyepiece holders, it would be fine, but this is rarely the case. Thumb screws can also dent and scratch the tube and put strain on the filter glass. Thumb screws are simply a "one size fits many" manufacturing shortcut and provide a false security.

CAN THE TELESCOPE OPTICS GET HOT OR DAMAGED? No, all the heat and intense light is blocked before it can enter the telescope. Your telescope may get warm from sunlight shining on it, not from the small amount of visible light transmitted through the filter.

WHAT DETAIL IS VISIBLE? Sunspots and surface granulation are the two main features. The only detail that cannot be seen with a standard filter (commonly called white light filter) are prominence and flares which require our highly specialized H-Alpha filter system.

The illustrations shown below are typical of Thousand Oaks filters and do not necessarily show the specific filters described. 1/1,000th of 1% (Optical Density 5). Great for both visual and photographic use.

CLEAR APERTURE

CELL OD

PART #

40mm\1.50″

50mm\2.00″

S-2000

45mm\1.75″

60mm\2.32″

S-2325

50mm\2.00″

70mm\2.75″

S-2750

60mm\2.37″

76mm\3.00″

S-3000

60mm\2.37″

82mm\3.25

S-3250

80mm\3.15″

90mm\3.50″

S-3500

80mm\3.15″

95mm\3.75″

S-3750

80mm\3.15″

101mm\4.00″

S-4000

90mm\3.50″

108mm\4.25″

S-4250

101mm\4.00″

114mm\4.50″

S-4500

101mm\4.00″

120mm\4.75″

S-4750

101mm\4.00″

127mm\5.00″

S-5000

101mm\4.00″

133mm\5.25″

S-5250

114mm\4.50″

139mm\5.50″

S-5500

127mm\5.00″

146mm\5.75″

S-5750

127mm\5.00″

152mm\6.00″

S-6000

127mm\5.00″

158mm\6.25″

S-6250

127mm\5.00″

165mm\6.50″

S-6500

152mm\6.00″

181mm\7.12″

S-7125

152mm\6.00″

190mm\7.50″

S-7500

152mm\6.00″

203mm\8.00″

S-8000

177mm\7.00″

212mm\8.37″

S-8375

177mm\7.00″

222mm\8.75″

S-8750

203mm\8.00″

236mm\9.312″

S-9187

203mm\8.00″

241mm\9.50″

S-9500

203mm\8.00″

247mm\9.75″

S-9750

203mm\8.00″

254mm\10.00″

S-10000

203mm\8.00″

266mm\10.50″

S-10500

228mm\9.00″

273mm\10.75″

S-10750

254mm\10.00″

292mm\11.50″

S-11500

254mm\10.00″

305mm\12.00″

S-12000

254mm\10.00″

311mm\12.25″

S-12225

279mm\11.00″

317mm\12.50″

S-12500

254mm\10.00″

330mm\13.00″

S-13000

304mm\12.00″

349mm\13.75″

S-13750

317mm\12.50″

387mm\15.25″

S-15250

355mm\14.00″

406mm\16.00″

S-16000

355mm\14.00″

432mm\17.00″

S-17000

355mm\14.00″

447mm\17.625″

S-17625