Скачать или смотреть Why is Infinity Focus Not ACTUALLY Infinity?

When I first started shooting, I always thought that dialing the focus ring to the very end (infinity) would provide perfectly sharp stars. After all, you can't really photograph anything further away than the galaxies... But I still have yet to see a single lens that is in focus on the stars at the end of the focus ring.

This is due to a couple of factors. Temperature can cause the elements within the lens to expand or contract, which changes the true focal point. Additionally, each lens is uniquely designed, meaning the true infinity point on two lenses may be slightly different.

I always test with my lenses so I know where the true infinity point is. That way, I don't have to struggle to find focus in the dark. Some people even mark the lens barrel to help them focus in the dark. Make sure to test your own lenses, as your results may vary!