refractors

Apochromatic vs Achromatic Refractors Explained

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If you’re new to astronomy, you might be wondering about the difference between apochromatic and achromatic refractors. Don’t worry. The lingo about ‘APO’ and then doublet vs triplet confused me too. What did it all mean? So I did some research and put this together. Achromatic refractors are generally more affordable and for that reason … Read more

Refractor Telescope Distorted Image Problem: Astigmatism

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Having a refractor telescope distorted image problem? It could be due to an aberration called astigmatism. Here’s what to know. When we look through a telescope, we want the image to be clear and sharp. Astigmatism is a type of off-axis aberration that interferes with this. Astigmatism in refractor telescopes and its effect on image … Read more