solar filters:
Type 2 + Glass: Made with high quality hand selected 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 5.0). Great for both visual and photographic use. Solar image is yellow orange.
R-G Solar Film: Designed with quality and cost in mind, our R-G solar film provides a superior image of the sun that rivals our glass solar filters at a lower price. Unlike other solar filter, the R-G solar film will provide a more pleasing and natural Yellow- Orange image of the sun our customers have come to know and love through our Solar Glass Filter product line. The R-G film will also be available in sheets for those who like to make their own solar filters. Please click tabs on the right for Safety and other information.
Black Polymer: This material is used as a low cost alternative where only low magnification is used such as with binoculars, threaded camera filters, eclipse viewers and finder scopes. The advantages of this material is that it is stronger than Mylar and other thin film solar filters that are available currently. The actual filtering properties are protected within the substrate.
WHAT SIZE filter will fit my telescope?:
The application table 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. If you do not see your brand and model, simply choose the closest outer cell I.D. size larger than the outside diameter measurement from 4" to 4 3/16". Do not choose a size the same as your O.D. since this will be too tight and not allow room for felt lining. Ample felt is included for custom fitting.
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 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 10"+ is still preferred for better resolution, it can be stopped down using a simple mask as conditions dictate.
mounting:
The inside of the cell will be lined with felt or unlined depending on the telescope brand and aperture. If your filter is too loose, it can be custom fitted using felt or tape on inside of cell. The filter should not fit too tightly or the optical surface may be distorted due to stress on the cell. If you have purchased an un-mounted filter and will be mounting it in your own cell, be sure to mount it in such a way as to allow for thermal expansion and contraction. The glass should not be firmly cemented or clamped within the cell or holder.
Velcro is also provided to secure the Filter to the Telescope for added safety.
Pricing:
Click below for Pricing by selecting the Type of Filter, (Glass-Left Column or R-G Solar Film-Right Column) and the Telescope Manufacturer.
For pricing on Individual R-G Solar Film Sheets for those of you who want to make their own solar filter please CLICK HERE.
For Individual Black Polymer Sheets, please CLICK HERE.
For Telescopes not listed please contact Thousand Oaks Optical with Telescope Type and Outer Diameter of Tube (measured as accurately as possible) for correct size and pricing.
Please contact us for a Dealer nearest you!