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Whenworking with any optical instrument, there are a few things to remember to ensure you get the best possible image.
• Neverlook through window glass. Glassfound in household windows is optically imperfect, and as a result, may vary in
thicknessfrom one part of a window to the next. Thisinconsistency can and will affect the ability to focus your telescope.
Inmost cases you will not be able to achieve a truly sharp image, while in some cases, you mayactually see a double image.
• Neverlook across or over objects that are producing heat waves. Thisincludesasphalt parking lots on hot summer days or
buildingrooftops.
• Hazy skies, fog,and mist can also make it difficult to focus when viewing terrestrially. Theamount of detail seen under
these conditionsis greatly reduced. Also,when photographing under these conditions, the processedfilm may come out a
littlegrainier than normal with lower contrast and underexposed.
• If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece
attachedto the telescope. Whenusing a camera, however, you should always wearcorrective lenses to ensure the sharpest
possiblefocus. Ifyouhave astigmatism, corrective lenses must be worn at all times.