Photography Accessories / How to Choose Filter Protectors for Camera Telephoto and Wide-Angle Lenses?

Recently, J. LIN STUDIO purchased a Nikon telephoto zoom lens, the “Nikon AF-S NIKKOR 70-200mm f/2.8E FL ED VR,” commonly known among photography enthusiasts as the “Little Black Seven.” After several real-world shoots and rigorous testing, it must be said that this is a top-tier flagship lens that is nearly perfect in optical resolution, autofocus speed, and image stabilization performance.

However, whenever a photographer opens the packaging box of a new lens, two classic soul-searching questions always surface right on cue:

1. First question: Should I add a filter protector to this new lens?
2. Second question: If I decide to add one, how do the selection dimensions differ between telephoto lenses and wide-angle lenses? And how should one choose among the major brands on the market (B+W, Marumi, Kenko)?

This article will thoroughly analyze the philosophy of choosing a filter protector from the perspectives of optical principles, real-world risks, and equipment maintenance.

Should You Add a Filter Protector to Your Lens? The Real Trade-off Between Two Camps of Photographers

In photography circles, the debate over “whether to add a filter protector” has never stopped, and it can roughly be divided into two major camps: the “bare-lens pure image quality camp” and the “safety protection realist camp.”

1. The Bare-Lens Image Quality Camp: One Less Layer of Glass, One Less Optical Loss

From the perspective of optical engineering, L himself actually leans toward the camp of photographers who “do not use a filter protector.”

The internal optical structure of modern professional lenses is extremely precise, often composed of 15 to 20 or more high-grade aspherical lenses, ED low-dispersion lenses, and expensive Nano Crystal Coat. Optical engineers spent countless R&D budgets precisely to solve chromatic aberration, spherical aberration, and light refraction loss.

However, when you screw an extra flat piece of glass onto the very front of the lens, even if that filter claims a light transmittance of up to 99.5%, it still forcibly adds two air-contact surfaces to the entire optical system. This brings the following potential costs:

• Increased flare and ghosting: When shooting against the light, doing night street photography, or when the frame contains strong point light sources, secondary reflections easily occur between the back of the filter protector and the front element of the lens, causing light spots that cannot be erased.
• Degradation of corner resolution: For inexpensive filters or those with insufficient manufacturing precision, tiny flatness errors on the glass surface will directly undermine the corner sharpness that large-aperture lenses pride themselves on.

Therefore, for the author’s 105mm macro lens (Micro-Nikkor 105mm), travel lens (Nikon 24-120mm F4), and other fixed-focal working lenses under NT$10,000, he basically insists on “going bare” to enjoy the purest optical resolution and true colors.

2. The Safety Protection Camp: Facing Top-Tier Lenses Over NT$50,000, Reality Ultimately Requires Compromise

However, “theory is full, but reality is bony.” When a lens’s price exceeds NT$50,000 or NT$70,000 (such as the Nikon Little Black Seven or the Canon 70-200mm f/2.8L IS III), it becomes hard to maintain a completely carefree mindset.

In real outdoor shooting, the front element of the lens is exposed at all times to uncontrollable external environments:

• High-salinity saltwater mist drifting in the air during seaside work;
• Tiny sand and stones splashing at high speed under strong winds;
• Umbrella tips or children’s fingers suddenly poking over when photographing crowds at events.

If the front element is shattered by a physical impact, or its coating is corroded by acidic stains, the original manufacturer’s quote for replacing the entire front lens group is often over NT$10,000 to NT$20,000, and it may even need to be sent back to the overseas factory for optical axis recalibration. Therefore, adding a top-tier filter protector with excellent optical quality to a “high-priced lens” is essentially like buying an “accident insurance policy” for a valuable asset — in extreme conditions, sacrificing a NT$2,000 filter to preserve the expensive front element intact.

The Core Truth That Overturns Perception: The Lens Hood Is the First Line of Physical Defense!

Whether you are in the image quality camp that insists on not attaching a filter, or the safety camp that feels uneasy without a filter, there is one crucial concept you must always remember:

Compared with a filter protector, the accessory that truly provides the strongest physical protection for a lens is always the “lens hood”!

Many photography beginners, after buying a new lens, habitually reverse-mount the included lens hood onto the lens barrel, or even leave it in the dry cabinet and not bring it out, mistakenly believing that as long as a filter protector is screwed on, everything is safe. This is actually a serious case of putting the cart before the horse.

Although the lens hood was originally designed to block harmful oblique side light, prevent glare in the frame, and improve image contrast, its physical structure brings extremely strong defensive effects during daily carrying and shooting:

1. Preventing accidental contact by fingers and foreign objects: The deep barrel of the lens hood naturally blocks the chance of fingers inadvertently touching the front element.
2. Absorbing the kinetic energy of falls and impacts: When the camera is accidentally dropped or hits a hard object, the engineering plastic lens hood bears the impact first, absorbing most of the kinetic energy through the latch releasing or its own fracturing and deformation, protecting the lens body and the internal autofocus motor.
3. Avoiding secondary damage from broken glass: If the camera is dropped and only the filter protector is there to take the hit, the thin filter glass is extremely easy to shatter directly; under the impact of gravity, the sharp broken glass shards will ruthlessly scratch the expensive coating of the lens’s front element like emery. If…