Beware Newton’s Rings

Aurora photographers can have a rude surprise in store if they use a protective lens filter

And you thought the most expensive part of photography was the camera.

Just wait till you start buying lenses that really perform well in low light for the aurora — wide viewing angles and fast apertures all mean more glass, and more money — in the same ballpark as your camera.

Protection for an optical price

The conventional wisdom is to protect this investment — one scratch on the large exposed…