Focusing Tips

Focusing manually is something of an art.  Focusing is discussed in detail in several sections of this website including the Basics of CCD Imaging and Software Instructions sections.  The following section gives some helpful hints to make the process of focusing go smoother.

• Make sure the CCD camera is in low-resolution mode to begin with.  This will speed up the process by shortening the exposure time.
   

• Start by visually estimating focus.  Get close by making the star as small as possible.
   

• Once the focus is close, switch to high-resolution mode to get a better image of the star for a more accurate focus.
   

• Take 2 or 3 exposures between focus adjustments to allow any vibrations to settle out.
   

• Refocus during the night since temperature changes can cause a telescope to defocus.
   

• Try refocusing for each color filter if doing RGB imaging.  Sometimes there is a slight difference in focus between each filter.
   

• Be patient!  A little extra time spent focusing will make for much better images!

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