This lens is optimal for astronomy, observation, and digiscoping!

Askar has been making high quality telescopes. One of their newest items is the 71f Apochromatic (APO) Quadruplet lens, which can be used for terrestrial viewing also. An APO lens is a type of lens that can focus all colors of light into a single point, meaning that there’s little to no chromatic aberration (color fringing, especially at edges of high contrast), creating a view that’s sharper than a standard lens. Quadruplet APO lenses are known to be better than standard APO lenses, because they have some more APO optical components to correct for Chromatic Aberration even more. Although there are various levels of correction of lenses that are APO lenses, this would be the third level, after Doublet APO lenses. The price for this item is relatively low, however, and the focal length is relatively versatile (490mm)!

https://www.highpointscientific.com/askar-71f-flat-field-refractor?utm_source=bing&utm_medium=cse&utm_term=ASK-71F&utm_source=bing&utm_medium=cpc&utm_campaign=432151742&utm_content=1232552799287015&utm_term=&msclkid=5557161d8460132fe79d703d933ed56d