Buying a used camera lens on eBay is one of the best value propositions in photography. Used lenses hold their optical quality almost indefinitely — glass does not degrade with use the way mechanical and electronic components do. A well-maintained lens from the 1970s can outperform a new budget lens from 2026. But the used lens market also contains plenty of poorly maintained, misrepresented, or genuinely faulty glass. Knowing what to look for protects your investment and ensures you get a lens that performs as expected.
This guide covers every aspect of used lens inspection — what to check, what to ask the seller, what is acceptable, and what is not.
The Hierarchy of Lens Faults — What Matters Most
Not all lens faults are equal. Before going through individual checks, understand this hierarchy of severity:
- Fungus: Never acceptable. Avoid any lens with fungus.
- Severe haze/fogging: Significantly degrades image quality. Avoid unless heavily discounted.
- Oily aperture blades: Very common, affects shooting. Factor in CLA cost or avoid.
- AF failure or malfunction: Expensive to repair. Avoid unless heavily discounted.
- IS/VR failure: Critical for telephoto lenses. Expensive to repair. Verify carefully.
- Moderate internal haze: Reduces contrast. Acceptable at significant discount.
- Light cleaning marks on elements: Minimal optical impact. Generally acceptable.
- Cosmetic damage to barrel: No optical impact. Acceptable at moderate discount.
- Minor internal dust: No visible impact on images. Completely normal in used lenses.
Glass Elements — The Most Critical Check
The optical elements are the heart of a lens. Damage here directly affects image quality and is often expensive or impossible to repair cost-effectively. Ask the seller for photos of every element held at 45 degrees to a bright light source — this is the standard method for revealing internal issues that normal photos miss.
Fungus
Fungus appears as web-like or branching growth on or between optical elements. It develops in humid conditions when organic matter (dust, fingerprint oils) is present. Even minor fungus is a serious problem for several reasons: it reduces contrast and sharpness, it spreads over time (consuming the anti-reflection coatings on the glass), and it is expensive to remove — a fungus cleaning typically costs $80-$200 and may not be 100% effective.
Verdict: Never buy a lens with fungus unless it is essentially free and you have a specific artistic reason for wanting it.
Haze and Fogging
Haze appears as a milky, cloudy, or frosted appearance on or between elements. It can result from lubricant vaporisation (balsam separation in cemented elements), fungal etching after fungus removal, or chemical breakdown of coatings. Moderate to severe haze significantly reduces contrast, causing flat, washed-out images particularly in backlit conditions.
Minor haze — a very slight cloudiness visible only in direct raking light — has minimal practical impact and is acceptable in vintage lenses at appropriate prices. Anything more significant should be avoided or heavily discounted.
Scratches
Small cleaning marks on the front element — the fine circular scratches left by improper cleaning with rough material — have very little impact on image quality in most shooting situations. They can cause slightly increased flare in extreme backlit situations but are otherwise invisible in the final image. Cosmetically they are undesirable but functionally they are acceptable.
Deep scratches — gouges visible to the naked eye in normal light — are more concerning and can affect image quality, particularly on the rear element. The rear element has more direct impact on image quality than the front.
Internal Dust
Internal dust is virtually universal in lenses more than a few years old. A few visible dust particles inside a lens have no visible impact on images — the dust is too far from the focal plane to come into focus. Even significant internal dust typically causes no measurable reduction in image quality. Do not be put off by sellers who honestly disclose internal dust — it is normal and harmless.
Aperture Blades — The Most Common Fault
The aperture diaphragm consists of multiple thin metal blades that open and close to control the amount of light entering the lens. In older lenses, lubricant from the focus mechanism can migrate to the aperture mechanism over time, coating the blades with oil.
Oily aperture blades prevent the diaphragm from closing properly and cleanly. Instead of snapping to the selected aperture, oily blades move sluggishly, unevenly, or not at all. In practice, this means you may be shooting at a wider aperture than selected, with inconsistent exposure, and without the ability to stop down for depth of field control.
How to check: Ask the seller to set the lens to f/8 or f/11 and look through the rear of the lens while pressing the aperture stop-down lever or button. The blades should snap to a clean, even polygon immediately. On auto-aperture lenses, the blades should open fully when the lever is released and stop down cleanly when pressed. Any sluggishness, oil sheen on the blades visible in a raking light, or uneven closure indicates oily blades.
Cost to fix: A CLA (clean, lube, adjust) service from a reputable technician costs approximately $40-$80 for most vintage lenses. This resolves oily blades and also addresses stiff focus rings and other mechanical issues. Factor this cost into your offer price.
Autofocus — Testing and Verification
For modern autofocus lenses, AF performance is critical. AF faults are expensive to repair — often more than the lens is worth at lower price points.
Ask the seller to confirm: AF activates immediately when the shutter button is half-pressed (no delay), AF locks on static subjects accurately and consistently, AF does not hunt (repeatedly searching back and forth without locking), and AF works at all focal lengths (for zoom lenses).
On Sony E-mount, Canon RF, and Nikon Z bodies, you can also test AF in video mode — continuous AF should track smoothly without breathing or hunting. AF that works in single-shot mode but fails in continuous AF for video is a partial fault worth factoring into price negotiations.
Image Stabilisation — Essential for Telephoto Lenses
IS/VR (Image Stabilisation/Vibration Reduction) failure is unfortunately common in used telephoto lenses. The gyroscopic elements that detect camera movement are mechanically complex and subject to wear. Repair costs are high — typically $150-$350 — often making repair uneconomical for lenses at lower price points.
How to verify: Ask the seller to half-press the shutter button with the lens pointed at a scene and confirm: a slight mechanical thud or click is heard/felt as IS engages, the viewfinder image visibly stabilises rather than drifting, and IS disengages cleanly when the shutter button is released. A grinding or whirring noise from IS indicates impending or current failure. IS that engages but does not actually stabilise the image is also faulty.
Physical Condition — What Matters and What Does Not
Cosmetic wear on the barrel: Paint wear, small dents, and worn markings on the barrel have zero optical impact. A heavily worn lens that works perfectly is worth buying at the right price.
Focus ring stiffness: Stiff focus ring is usually dried lubricant — fixable in a CLA service. Very loose focus ring can indicate bearing wear or missing lubricant and is harder to fix.
Zoom ring condition: Zoom rings should rotate smoothly throughout the range. Stiffness at certain focal lengths can indicate moisture ingress or lubricant breakdown.
Mount condition: Inspect the lens mount (the rear metal ring that connects to the camera) carefully. Any dents, cracks, or damaged threads mean the lens may not mount securely. This is a serious fault — avoid.
Filter threads: Damaged front filter threads prevent UV filter attachment but have no optical impact. Minor thread damage is acceptable.
Verifying eBay Sellers
Seller reputation matters enormously for used lens purchases. Look for: 99%+ positive feedback overall, a track record of selling camera equipment specifically (check their completed listings), detailed listing descriptions that honestly disclose faults, multiple photos including element shots, and a clear return policy.
Top Rated sellers on eBay offer additional buyer protection beyond the standard eBay Money Back Guarantee. Read negative feedback carefully — patterns of "not as described" complaints, disputes about condition, or slow shipping are all warning signs. A seller with 100% feedback on 15 transactions is less reassuring than one with 99.2% across 800 transactions.