Thousand Oaks Optical TO TYPE II SOLAR FILTER 17.62" ID OFF-AXIS 17625A
Item No. 722-17625
Eligible for Scope City Rewards at Check-out
Manuf. No. TO Optical 17625A
Note: The size description is the INSIDE diameter of the solar filter. The OUTSIDE diameter of your scope must be smaller than this size for the filter to fit. If the size description is a range of sizes, the OUTSIDE diameter of your scope must be smaller than the largest size listed in the range.
Solar Filters GLASS SOLAR FILTERS
- CLEAR APERTURE: 152mm6.00"
- OUTER CELL I.D.: 447mm17.62"
- OFF-AXIS 2+: Meade 16 S/C
- PART #: 17625A
TYPE 2 PLUS: Made with high quality hand select glass coated with our exclusive Solar II Plus. The most durable glass filter on the market. Transmission is 1/1,000th of 1% (Optical Density 5). Great for both visual and photographic use. Solar image is yellow-orange. Guaranteed fifteen years.
ARE THE FILTERS COMPLETELY SAFE?
All of our Glass 2+, RG-Solar Film & Black Polymer filters are completely safe for unlimited visual use. If handled with care and common sense, all will last a minimum of 20 years to life.
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.
FULL APERTURE VERSUS OFF-AXIS (REDUCED APERTURE)?
For telescopes up to 5" aperture, off-axis is not an advantage. Larger apertures suffer more from daytime atmospheric turbulence. This turbulence is magnified by the aperture. Perfect daytime "seeing" only occurs about 1% of the time. Off-axis reduces the aperture and increases the focal length thus reducing the turbulent effects. We recommend and only offer off-axis for 10" and larger telescopes. The solar image is not darker with reduced aperture as we allow for this in the coating density. When viewing through the eyepiece, the field of view is not reduced; it looks the same as full aperture. If full aperture for 6" to 8" is still preferred, it can be stopped down using a simple mask as conditions dictate.