Apochromatic vs Achromatic Refractors Explained

Achromatic Vs Apochromatic Refractors

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