Thousand Oaks Optical - Full Aperture Glass Solar Filter TYPE 3+

for Meade DS-16

 Lighter density, 1/100th of 1% (Optical Density 4) for maintaining fast
shutter speeds when using "slow" fine grain films. For photographic use only.
(Visual focusing through the camera viewfinder is safe) Solar image is
yellow-orange. Guaranteed fifteen years.

Frequently Asked Questions

WHICH FILTER IS THE SAFEST? All our filters, except for the lighter density photographic
version, 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 MY 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 visual light transmitted through the filter.

WHAT DETAIL CAN I SEE? Sunspots and surface granulation are the two main features. The
only detail that cannot be seen with a standard filter are prominence and flares which require our
highly specialized H-Alpha filter.

IS FULL APERTURE BETTER THAN OFF-AXIS (REDUCED APERTURE)? For telescopes up to 5"
aperture, off-axis is not an advantage. However, 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 increases the focal length and reduces the turbulent
effects. As a rule of thumb, order off-axis if your telescope has a focal ratio f/7 or lower in
the 6" to 8" aperture range, or if it's larger than 8" aperture. 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. Reduced center
aperture is used for refractors. If full aperture is still preferred, it can be stopped down using
a simple mask as conditions dictate.