As much as I try to keep my gear in good shape, things just happen. Lenses get dropped, soaked and cooked (in back of the car in Baja). The first sign that you are really using your gear a lot is when the rubber grip starts to peel away, or gets loose on your lens. Next is the wear marks that rub off the gold letters. And finally the dreaded….’scratch on the front element.’ Disaster! Or is it really?
I have 3 lenses that have scratch marks on the front element, but I am not too worried. These tiny scratches are not going to show up in the final image unless I am pointing my lenses directly at the sun. Lens scratches will produce a flare mark when you are shooting sun stars. And occasionally when you are shooting a backlit scene depending on your angle to the sun. But for most of your shooting, you probably won’t see any difference. My 24-120mm, which I use to shoot rock climbing while hanging on a rope, has lots of scratches. I used this lens for years without a problem. But finally the rubber grip starting coming off, so I sent it into Nikon. For a modest fee Nikon replaced the grip and replaced the front element. When my lens came back it looked like new. If you have a heavily scratched front element, a service center can replace the front element. The price will depend on the lens and how big the front glass is….I’ve heard of sports photographers replacing the front element of a 600mm F4.
How do you avoid scratching the front element in the first place? First, use a lens hood. These add a buffer to the element from bumps and impacts. Next, put the lens cap on when you are not using the lens. I think a lot of scratches occur when the lens get put in your pack without a cap, and bumps up against other lenses and camera bodies. Another option it to use a front clear filter. I normally don’t use a front filter unless the conditions are really bad like blowing sand or salt water. Adding more glass to the front of my lens adds more chance of flare and other issues like Newton Rings when you photograph the Aurora. But if you are really worried, then add a very high quality filter to protect your lens.
Don’t loose sleep if you get a tiny scratch on your front lens element. These elements are treated to minimize imperfections on the front glass. Better to focus on your image, and get the shot.