OPTICAL FILM SOLAR FILTERS:

R-G SOLAR FILM: Designed with quality and cost in mind, our new R-G Solar Film provides a superior image of the sun that rivals our glass solar filters at a very economical price. Unlike other solar filters, the R-G Solar Film provides a more pleasing and natural Yellow-Orange image of the sun our customers have come to know and love through our Glass Solar Filter product line. The R-G Film is also available in sheets for those who like to make their own solar filters.

BLACK POLYMER: A lower cost alternative where only low magnification is used such as with binoculars, threaded camera filters and finder scopes. Stronger than Mylar with the filtering properties protected within the substrate. Guaranteed fifteen years.

FREQUENTLY ASKED QUESTIONS:

WHAT SIZE DO I ORDER? 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 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? 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.

WHY ARE THREADED CAMERA FILTERS ONLY AVAILABLE IN BLACK POLYMER? Glass filters have highly reflective coatings that can cause internal reflections between the filter and camera lens since the filter and lens are in close proximity. This problem is less likely to occur with telescopes, however, mounted telescope filters can be tilted slightly to move any internal reflections off the central axis and out of view.

FULL APERTURE