To complement the other previous posts about photographic filters, here are few additional elements.
Is a UV filter harmful?
First, I would like to demonstrate once again the critical importance of having a very good quality filter rather than the usual plastic junk. Too often, we forget that the filter is degrading the image quality and that the better the lens, the worst the impact. To clearly show this impact, LensRentals tried to stack up to 50 filters on the same lens. the result is so immediately obvious that you don’t need to go pixel-peeping at 100% scale:
But even one filter will decrease image quality.
Of course, if you want to compare the impact of the impact difference between a pro filter and a cheap run-of-the-mill filter, you can stack just 5 pro UV filters and 5 cheap UV filters. Here again, you’ve got food for thought before you buy your next photo filter:
I insist! this last test does not use 50 filters, but only 5 UV filters and the result is immediately perceptible to the naked eye of the non-expert, even if you’re not looking for it. With only one filter, you can do the test by your own and decide that using filters is a matter of thoughtful choice.
How Polarizing Filters Work?
This is one of the best and simplest explanations and demonstrations of the operation of these basic filters: A Polarizing Filter on the left and the Neutral Grey Filter on the right.
Polarizing Filters for Photo and Video from Olivia Speranza on Vimeo