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    Harpia 95 Depth Of Field At Full Zoom.

    Hi Dave, Any motion you see is air turbulence, which unfortunately obscures the patterns you want to see. Choosing a star close to the zenith and avoiding warm ground surfaces in front of the scope might help, but sometimes there is a layer of turbulence in the atmosphere that can't be...
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    Harpia 95 Depth Of Field At Full Zoom.

    One note of caution. The other scope really needs to be sensibly perfect for a useful comparison. It wouldn't be a big surprise if both scopes are suboptimal. The advantage of a star test is that it compares your scope to an absolute optical standard, not another scope of unknown quality, and...
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    Harpia 95 Depth Of Field At Full Zoom.

    To minimize the issue of unsteady air try using a resolution target at a relatively short distance, perhaps 10-30 meters, preferably over shaded grass. Henry
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    Harpia 95 Depth Of Field At Full Zoom.

    "Focus hunting" is a possible sign of excessive aberrations, typically spherical aberration or astigmatism. No scope brand or model is immune. You may have noticed the mention of "star-testing" as a way to diagnose the problem or problems that cause observations like yours. Id start with reading...
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