User manual ORION TELESCOPES & BINOCULARS SLRFILTERS

[. . . ] Aim the telescope at the Sun by moving your tube assembly until the smallest shadow is cast on the ground. Allow the telescope and filter to equalize to outside temperature for at least 15 minutes. Direct sunlight may warm the tube assembly enough to cause internal heat currents that can degrade image quality, especially on dark-colored telescopes. [. . . ] Loose dust on the inside surface can be blown off or lightly dusted with dry cotton. Inspection & Maintenance Pinholes and scratches are common in all glass solar filters. Microscopic particles on the glass can not be completely eliminated in the coating process, and a minute amount of light transmitted through the resulting "pinholes" will be visible. Normal usage of the filter will reveal new pinholes and may also introduce small scratches. Every effort is made to minimize pinholes in the manufacturing process. The glass is cleaned and coated three times in the coating process, meaning that the coating is even across the entire aperture and most pinholes will not be entirely transparent. A few minutes spent occasionally touching up any brighter pinholes will prevent any possible "ghosting" due to scattered light. Opaquing of the pinholes should be done on the inside coated surface with a fine-point "permanent" felt marker. Although it would never be necessary with our filters, as many as 20 touch-ups per inch of aperture could be done without loss of resolution or significant loss of brightness. There is no Mounting the Solar Filter The inside of the filter cell will be either lined with foam tape or unlined, depending on the telescope. The filter should fit just tight enough to keep from slipping off when the telescope is pointed down. If your filter is too loose, it can be custom fitted by applying the supplied foam tape inserts on the inside rim of the cell. The filter should not fit too tightly or the optical surfaces may be distorted due to stress on the cell. The view through your telescope should be comfortable and not appear excessively bright. Keep the front of any finder scope covered if it is not equipped with a solar filter. Even if you do not look through it, unfiltered sunlight may melt internal parts of a finder scope. IN 025 Rev. [. . . ] The Sun is very difficult to photograph because of poorer "seeing" conditions caused by unavoidable heat currents associated with daytime viewing. The highest possible resolution for any land-based telescope, regardless of location, is about 1 arc second. Ideal seeing for any location will be available less than 5% of the time. [. . . ]