![Confused with scope focal length - what am I missing? - Beginners Forum (No Astrophotography) - Cloudy Nights Confused with scope focal length - what am I missing? - Beginners Forum (No Astrophotography) - Cloudy Nights](https://www.cloudynights.com/uploads/monthly_07_2016/post-29900-0-45377400-1469838557_thumb.jpg)
Confused with scope focal length - what am I missing? - Beginners Forum (No Astrophotography) - Cloudy Nights
When building a refracting telescope, does the diameter of the eyepiece matter? And why do we need to move the eyepiece (as in my textbook) if the image is always focused at
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