Sigma

Sigma AFK9A0 105mm Protector Filter

Name: Sigma AFK9A0 105mm Protector Filter
Brand: Sigma
SKU: AFK9A0

★★★★★4.7 (252 reviews)

Shield your 105mm lens from dust, scratches, and accidents without sacrificing optical clarity.

$148.99*$162.00Save 8%

*Price sourced from Amazon.com. Last updated:Jul 14, 2026.Price and availability are subject to change.

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Overview

The Sigma AFK9A0 105mm Protector Filter is built for photographers who want to keep their high-end lenses safe without compromising image quality. At 105mm, this filter fits a select range of professional and specialty lenses — typically fast telephoto or wide-aperture zoom lenses that command a significant investment. A clear protector filter acts as a first line of defense, absorbing the bumps, dust exposure, and accidental contact that would otherwise land directly on your lens's front element.

Sigma positions this filter as part of their lineup designed to complement high optical performance, meaning it is engineered to be as transparent as possible in the image path. For daily use — event shooting, outdoor work, or travel — having this filter permanently mounted lets you worry less about handling and environmental hazards. Cleaning a flat filter surface is also simpler and lower-risk than wiping a coated front element directly. For anyone with a 105mm-threaded lens, this protector is a sensible insurance policy against costly repairs.

Key Features

Protector

New Concept Filters that suit the high optical performance

Protects the lens effectively

Specifications

Filter Type

Protector

Filter Size

105mm

Purpose

Lens protection from dust, scratches, and damage

Brand

Sigma

Model

AFK9A0

Pros & Cons

👍 Pros

Provides a physical barrier against dust, fingerprints, and front element scratches
Large 105mm size fits specialty and professional lenses that use this less common thread diameter
Allows additional filters to be stacked on top for flexible creative use
Easier and cheaper to replace than repairing a damaged front lens element

👎 Cons

105mm filters are significantly more expensive than smaller common sizes
Large diameter adds slight extra weight and bulk to the front of the lens
An additional glass element in the optical path can introduce flare in harsh lighting if not kept clean

Frequently Asked Questions

Will this protector filter affect image sharpness or introduce color shifts?

It is designed to maintain high optical performance, providing protection without noticeably degrading image quality when the glass is kept clean.

What thread size does this filter fit?

It fits lenses with a 105mm front filter thread. Confirm your lens's filter diameter before purchasing.

Can I stack other filters on top of this protector?

Yes, like most protector filters it has front threads that allow you to attach additional filters such as polarizers or ND filters on top.

Is this filter multi-coated to reduce flare and ghosting?

Sigma designs their protector filters to complement high-performance lenses, though you should verify the specific coating details for this model if flare control is a priority for your shooting conditions.