Discover how used lenses are professionally tested and graded before resale. Learn the step-by-step process that ensures optical quality, mechanical precision, and buyer confidence in every purchase.

Behind the Scenes: How We Test and Grade Our Used Lenses

In the ever-evolving world of photography, used camera gear has become an essential resource for enthusiasts and professionals alike. Buying pre-owned lenses is a smart way to expand your creative toolkit while saving money. However, not all used lenses are created equal. Hidden scratches, mechanical wear, or optical issues can turn a seemingly good deal into a frustrating experience. That’s why trusted camera stores and dealers follow strict procedures to test and grade used lenses before offering them for sale.

But have you ever wondered how lenses are actually tested and graded? What steps are involved to ensure a lens meets quality standards? In this article, we’ll take you behind the scenes and reveal the comprehensive process of inspecting, testing, and grading used lenses, giving you confidence in every purchase.

---

Step 1: Visual Exterior Inspection

The first thing technicians do when a used lens arrives is perform a thorough visual inspection of the exterior. This step helps determine the cosmetic condition and detect any signs of impact damage or excessive wear.

Key aspects checked:

• Lens Barrel Condition: Scratches, dents, scuffs, or worn-out paint are noted.
• Mount Integrity: The lens mount is examined for scratches, deformations, or loose fittings that could affect attachment to a camera.
• Switches & Buttons: All external switches (AF/MF, IS/VR toggles, aperture rings) are tested for proper movement and responsiveness.
• Filter Threads: Damaged or stripped filter threads are red flags, as they may prevent the use of filters.

Lenses with cosmetic flaws are documented carefully. Minor scratches may only affect the lens’s appearance, but deeper dents could indicate internal misalignment.

---

Step 2: Optical Glass Examination

Next, technicians examine the front and rear glass elements for imperfections that could impact image quality.

Inspections include:

• Surface Scratches: Light cleaning marks are normal, but deep scratches—especially on the rear element—can affect sharpness and flare performance.
• Coating Condition: Special attention is paid to the integrity of anti-reflective coatings, as worn coatings can degrade contrast.
• Fungus Detection: Lenses are checked under bright light for web-like patterns that indicate fungus growth, which can spread if untreated.
• Haze or Fogging: Internal haze is caused by moisture exposure and can scatter light, reducing image clarity.
• Separation Issues: Also known as “balsam separation,” this defect shows as rainbow-like patterns due to separation between cemented elements.

Technicians use specialized LED lights and magnifying loupes to catch defects invisible under normal lighting conditions.

---

Step 3: Internal Dust & Debris Assessment

Virtually all lenses accumulate some dust inside over time. However, the amount and size of internal dust are important factors in grading.

• Minor Dust: Common and typically does not impact image quality.
• Heavy Dust or Debris: Excessive particles can reduce contrast or indicate improper storage conditions.
• Hair or Large Particles: Suggests previous disassembly or poor maintenance.

If internal dust is accessible, the lens may undergo light cleaning. For sealed lenses, a high dust level might result in a lower grading even if image quality remains unaffected.

---

Step 4: Mechanical Function Testing

For manual focus lenses:

• Focus Ring Smoothness: The ring should turn smoothly across its entire range without grinding, stiffness, or loose play.
• Aperture Ring Functionality: Click stops should be firm and precise; aperture blades must open and close consistently.

For autofocus lenses:

• Autofocus Motor Test: The lens is mounted on a compatible camera to test AF speed, accuracy, and noise level.
• Stabilization System Check: Lenses with built-in image stabilization (IS/VR/OS) are checked for proper activation and effective performance.

Any mechanical stiffness, looseness, or malfunctioning parts are documented and affect the lens’s grade.

---

Step 5: Functional Mounting Test

The lens is mounted on an appropriate camera body to verify:

• Mounting Fit: Ensures a secure and snug connection with no wobble.
• Communication Protocols: Electronic lenses are tested to see if aperture, focus, and EXIF data are correctly transmitted to the camera.
• Infinity Focus: Technicians verify that the lens can accurately focus to infinity, which can reveal misaligned optics.

---

Step 6: Optical Performance Testing

Beyond physical checks, real-world image testing is crucial to determine a lens’s optical performance.

Test procedures include:

• Sharpness Test (Center & Edges): Images are taken at various apertures to evaluate sharpness performance.
• Bokeh Quality Assessment: Out-of-focus rendering is examined, especially for portrait lenses.
• Flare & Ghosting Test: Shots are taken against strong light sources to assess flare resistance.
• Chromatic Aberration Check: High-contrast edges are inspected for color fringing.
• Distortion Patterns: Wide-angle and zoom lenses are checked for barrel or pincushion distortion.

Test shots are reviewed on calibrated monitors to identify any optical flaws such as decentering or focus shift.

---

Step 7: Cleaning & Polishing

If a lens passes all functional tests, it undergoes a professional cleaning session:

• Exterior Wiping: Lens barrels, rings, and mounts are cleaned of smudges and dirt.
• Glass Polishing: Front and rear elements are gently cleaned with lens-safe solutions.
• Dust Blowout: Internal dust that is reachable without disassembly is removed using air blowers.

This step ensures the lens not only functions well but also looks as presentable as possible.

---

Step 8: Grading the Lens

Based on its condition and test results, the lens is assigned a grade or condition rating. Though grading systems may vary by retailer, common categories include:

1. Like New / Mint – Flawless, looks and performs as new.
2. Excellent – Minor cosmetic marks, but flawless functionality.
3. Very Good / Good – Noticeable cosmetic wear; fully functional.
4. Fair – Heavy wear, may have minor optical or mechanical imperfections.
5. As-Is / Parts – Defects present; sold at a discount without warranty.

Every grade comes with a detailed description highlighting specific cosmetic marks, functional quirks, or optical defects, if any.

---

Step 9: Documentation & Photography

Before listing the lens for sale, high-resolution product images are taken to accurately show its condition. Detailed descriptions are written to inform potential buyers of:

• Cosmetic wear.
• Functional performance.
• Any minor issues found during testing.
• Warranty and return policy.

Transparency at this stage is crucial to maintaining buyer trust and reducing post-sale disputes.

---

Step 10: Warranty & After-Sale Support

Reputable dealers often provide limited warranties on used lenses (30-180 days), covering unforeseen functional defects. This assurance gives buyers peace of mind, knowing they can return or exchange the product if it doesn’t perform as expected.

---

Why This Process Matters

When buying a used lens from a trusted retailer, you’re not just paying for the item itself. You’re investing in:

• Thorough inspection.
• Honest grading.
• Functional testing.
• Post-sale support and warranties.

This rigorous process ensures that buyers can shop for used lenses confidently, knowing they’re getting gear that’s been professionally vetted and accurately described.

---

Conclusion

Behind every “Used – Excellent Condition” listing lies a detailed and methodical inspection process. From the moment a used lens arrives, it undergoes a comprehensive series of tests—visual checks, mechanical assessments, optical performance evaluations—to ensure it meets strict quality standards.

Understanding how lenses are tested and graded helps buyers appreciate the value of buying from trusted sellers rather than taking risks in unverified marketplaces. When you buy a lens that’s been properly inspected, cleaned, and graded, you’re not just saving money—you’re making a reliable, informed investment in your photography gear.

About Us Welcome to our webshop! eFiver.uk is a small UK based online shop with competitive prices and a growing number of photography products. We have a people-centred approach, so our customers’ satisfaction is our highest priority.

 

About products

We mostly sell used items. Sometimes we also sell fully working used electronics below market price, mainly Canon cameras or Canon camera lenses.

Why eFiver?

One of the motto of our company was to sell affordable items for low prices. But later we started to focus on photography products. Yet, still one of our aim is to sell affordable cameras and lenses.

Money Back Guarantee

For most of our products, we offer you a money back guarantee if you return your order within 14 days.

UK Orders

Ordering has never been easier. Simply order your products through our website. We delivered straight to you, quickly and fast.

Dispatch time: 3-4 working days. We dispatch all your orders from Monday to Friday (from Norwich). Most orders will be sent by Royal Mail or Hermes class.

Cancellation

We can cancel your order free of charge before dispatch (see also the return options).

If you have any question contact us or send an email to office@efiver.uk.

Thank you for visiting our webshop!

Among the most essential part of a digital SLR is the lens- or, more properly, lenses, because, unlike other types of digital cameras, which might utilize add-on lens adapters, the lens of a DSLR is totally interchangeable. I’m not going to inform you much about how lenses work. The majority of the rest of this area will handle useful matters connecting to interchangeable lenses on a DSLR. The only things you truly need to understand about lenses are these:

■ Lenses consist of precision-crafted pieces of optical glass (or plastic or ceramic product) called aspects, organized into groups that are moved together to alter the magnification or focus. The components may be based upon pieces of spheres, or not (in which case they are aspherical), and provided special finishes to decrease or get rid of undesirable reflections.

■ Lenses include an iris-like opening called a diaphragm that can be changed in size to admit basically light to the sensing unit. In addition to adjusting the amount of light that passes through the lens, the diaphragm and its shape impact things like relative overall sharpness of an image, the amount of an image that remains in focus, the brightness of your view through the viewfinder, and even the shape and qualities of out-of-focus highlights in your image. I’ll describe these elements in more information as they show up.

■ Lenses are installed in a real estate that keeps the aspects from rattling around and supplies a method to move them to change focus and magnification. The lens housing can include a microprocessor, a small motor for changing the focus (and, in non-DSLR electronic cameras, for zooming), and maybe a mechanism for reducing the effects of cam shake (called vibration reduction). Included are threads or a bayonet mount for attaching filters, a fitting that connects to your electronic camera, and different levers and electronic contacts for interacting with the cam body. You might find a switch or two for changing from autofocus to manual focus, locking a zoom lens so it doesn’t extend mistakenly while the cam is being carried, and a macro, lock/lockout button to restrict the looking for range of your autofocus mechanism so your lens won’t seek focus from infinity to a few inches away whenever you partly depress the shutter release. Everything else is details, and we’ll take a look at them in this and later chapters of this book. Lens Interchangeability The ability to remove a lens and swap it for another is one of the crucial advantages of the digital SLR. Interchangeable lenses make a very cool tool because they broaden the professional photographer’s flexibility in several ways:

■ Swapping lenses lets you alter the “reach” of a lens, from wide-angle to medium telephoto to long telephoto. The zoom lenses on non-SLR cameras offer some of this flexibility, but they can’t provide the zoom of the longest telephotos and telephoto zooms, nor the wide-angle point of view of the quickest focal lengths discovered in some interchangeable lenses and zooms

■ Interchangeable lenses let you pick a lens optimized for a particular function. Do everything zooms are necessarily a compromise that might perform fairly well in a broad series of applications, however excel at none of them. Using an SLR lets you select a lens, whether it’s a zoom or a repaired focal length lens (called a prime lens) that does a specific thing effectively undoubtedly. A lens with a zoom variety, extending from wide-angle to long telephoto might be plagued with distortion at one end of the variety or another (or both!). A multi-purpose lens is most likely much slower than an enhanced optic, perhaps with an f/4.5 or f/5.6 optimum aperture. With the schedule of interchangeable lenses, you can select a really quickly, f/1.4 lens when you need one, or select a lens that’s particularly excellent in a provided zoom range (say, 12-24mm). Select another lens for its splendid sharpness, or since it provides a dreamy blurred effect that’s perfect for portraiture. Use zooms when you need them and prime lenses when they are better fit for a task.

■ Lens swaps make it simple for those with extra-special requirements to discover some glass that fits their specific requirements. Fisheye lenses, those with a point of view control shifts, macro lenses for a bug’s eye view of that prize flower, or hyper-expensive super-long telephoto optics with built-in correction for electronic camera shake are offered to anyone who can afford them. As you know, however, lenses aren’t definitely interchangeable. Lenses designed to fit on one specific supplier’s brand name of video camera probably won’t fit on another supplier’s cam (although there are exceptions), and it’s highly most likely that you’ll discover that many lenses produced by the manufacturer of your digital SLR can’t be used with present cam designs. I can’t provide a thorough lens compatibility chart here, because there are hundreds of various lenses readily available, however you might discover some of the guidelines in this section helpful. The first thing to understand is that lens compatibility isn’t even a problem unless you have older lenses that you wish to use with your current digital camera. If you have no lenses to move to your new camera body, it makes no distinction, from a lens perspective, whether you choose a Nikon, Canon, Sony, Olympus, Pentax, or another DSLR. You’ll want to purchase existing lenses produced your video camera by the vendor, or by 3rd parties such as Tokina, Sigma, or Tamron, to fit your electronic camera. One exception might be if you had a hankering for an older lens that you might acquire used at an attractive cost. In that case, you’ll have an interest in whether that older lens will fit your new camera. You likewise might be thinking about backwards compatibility if you own a lot of costly optics that you want to use with your brand-new electronic camera. That compatibility depends a lot on the style approach of the video camera vendor. It’s easier to create an entire brand-new line of lenses for a new camera system than to find out how to utilize older lenses on the current devices. Some vendors opt for bleeding-edge innovation at the expenditure of compatibility with earlier lenses. Others bend over backwards compatibility.

Fireworks are relatively easy to photograph. It should be clear that something like this cannot simply be photographed by hand. With a little luck you can even use compact cameras. If you want more, you should use a manually operated camera. Also recommend a safe stand with a tripod or center punch cushion. In the simplest case, the camera can also be positioned reasonably firmly on a “grain cushion”. The most important thing when photographing fireworks is that the camera is safely and securely installed throughout the exposure. Because the principle is as follows: The camera exposes for several seconds and captures everything that is going on in the sky. In other words, we’re doing a long exposure .

I always take such night shots with a stable tripod. However, simple tripods are also suitable for lighter cameras, especially if you only need something like this for New Year’s Eve. From around 10 € you can get a simple tripod. Another possibility is the so-called “grain pillow”. To do this, you simply fill z. B. rice or peas in a bag, closes this and thus receives an individual base on which you can align the camera firmly. Disadvantage: Of course, something like this only works on a raised surface such as a table. But if you want to photograph the fireworks outside on New Year’s Eve and not from the balcony, you cannot avoid a tripod.

What must be set on the camera for fireworks?

The very simple way: no manual mode available

I already mentioned it at the beginning: The best thing is that the camera has a manual mode (“M”). If you cannot take photos manually with your camera, you can try the following:

The camera sits firmly on a tripod or something similar. Set the camera’s programmer knob to either AV mode (for Nikon A) or TV mode (for Nikon “S”). Or you simply select the program mode “P”.
However, it must be possible to switch off the flash!
With such compact cameras, however, make sure that you actually only have the sky in the picture and not a brightly lit object or a house wall!

Press the camera’s shutter button. The autofocus won’t find anything (it’s all black) and will eventually adjust to “infinity” – just right for fireworks in the distance. Now the camera initially only sees black and exposed and exposed (hopefully long enough). During this time, however, the fireworks are ignited and wander through the image, so to speak, or leave information on the camera’s chip, which is shown as the tail that you know from other photos or that you want to photograph yourself.

At some point the exposure will end automatically. With luck, you will be as a sufficient number of “tails” of fireworks recorded have. If your camera breaks the exposure immediately after a second even in the dark, it is unfortunately not suitable for this technique. You can easily try it out in a dark room at first.

The camera has a manual mode “M”

Here it gets a lot more interesting. In manual mode, fireworks can be photographed much better at night! After the camera has been placed on the tripod, it starts:

Set the M mode and deactivate the built-in flash here (or leave it folded in).

First manually set the ISO value to 100, at least to the lowest number that is possible.

Set the aperture to 8 or 11.

Set an exposure time of approx. 30 seconds on the camera.

Set the white balance so that the camera yellow light which awaits: So you select “sun” or better yet “light bulb”. Otherwise the photo will be too yellowish.

Manually set the focus to infinity.

If possible, take photos in “RAW mode” so that you can process the images better later.

Wait for the fireworks to really go off and press the trigger!

I put my Nikon on my Triopo tripod and exposed the longest time I could set with the Nikon DSLR: 30 seconds. I continued to work with the settings above: ISO 100 and aperture 8. However, I made a mistake with the white balance: I chose neutral light or “flash”. The light of the fireworks is not white but already very yellowish to red. In addition, the fog scattered the yellowish-reddish light all around.

I used an old analog Nikon wide angle with manual focus, which can easily be connected to modern digital cameras . Due to the long exposure time, I was able to photograph several fireworks following one another on just one picture!

Taking pictures in fog

Actually, I’m only semi-happy with my fireworks photos. For me they are far too red-tinged and not clear / brilliant enough. On the other hand, they are a good example of what fog can do and an incorrect white balance on the camera.
Due to the prevailing fog, all the lights of the city (all the street lighting and also a lot of fireworks that took place on the ground) were reflected and thus also visible in the sky. You have to imagine fog or haze as billions of tiny mirrors that “float” in the air and reflect (unfavorable) light towards the camera. That is simply unfavorable for brilliant images! It’s just like stargazing. The lights of the city are just as annoying there as they are in the haze in the sky.

I will also use a white balance on my camera next time, which corrects tones that are too yellow / too red. The white balance program “incandescent lamp” or “artificial light” would be ideal here. We don’t see it, because our brain automatically corrects something like this: The light from the incandescent lamp is similar to the yellow light from the street lighting, which is disturbing here. But the camera relentlessly reproduces something like that. Without white balance, the photos would get too strong a yellow cast, especially with such long exposure times.

“Catch” the fireworks even longer with long exposure

You don’t necessarily have to rely on e.g. B. Limit 30 seconds. If you have a remote release for your camera (unfortunately I don’t have something like this for my Nikon [yet “]), you can theoretically expose the whole night or capture the entire fireworks display in just one single picture.
The exposure time on the camera is set to “B”. “B” means bulb. This term comes from the old days of photography, in which a small balloon was screwed to the shutter release of the camera using a thin hose and an air pressure was generated by applying pressure, which activated the shutter release. With modern cameras this happens either via a cable or even via radio.
In any case, the camera now exposes exactly until you press the shutter release again. At 100 ISO and over 30 seconds, however, I would close the aperture of the lens further, otherwise the sky will be too bright: From 30 seconds I use aperture 11; from 60 seconds f-stop 16 and from 2 minutes fireworks f-stop 22.

If you want to expose even longer, we recommend using an ND filter . Then, however, it may be that the individual lights of the fireworks get too dark, because they only act on the camera’s chip for a few seconds. It may be possible to make them brighter again later in the image processing by changing the so-called “gradation curve” or by increasing the contrast.

A tip on composition

When photographing fireworks, I always make sure that not only sky + rockets are shown. Personally, that’s a bit too arbitrary for me. I always try to take pictures of other picture elements: trees, for example, or houses that are beautifully illuminated by the colorful fireworks.

If you want to be very colorful, in addition to the long exposure of the actual fireworks, you can manually flash the surrounding houses in the picture with a flash and a weak color filter in front of it during the long exposure. But don’t overdo it here. Because if you only flash very subtly, you will get the impression that this colored light is coming from the fireworks themselves! With such a trick you create an illusion or an even greater expressiveness of the image.

This tip does not always make sense, but it is definitely worth a try for motifs with nearby (up to approx. 20 meters) houses, walls, trees, etc.

Pay attention to the battery consumption

If you have installed your camera on a tripod outside (e.g. on a small hill) and are now waiting for the fireworks to be lit, you have a spare battery for the camera in your pocket as a precaution! The camera quickly drains the battery during long exposures! At least my Nikon DSLR does.

The trick with the black box

Finally, a tip that I already gave in my article about long exposure times: If you have longer exposure times, have a black box with you!
I swing the box in front of the lens in the empty phases, i.e. when a certain time elapses between the individual fireworks (of course so that I don’t touch it). With this shadowing I achieve the following:

The sky is not brightened unnecessarily and the contrast between the sky and the fireworks is increased significantly: the images become more brilliant!

In this way I prevent continuously illuminated elements in the picture from being unnecessarily overexposed (e.g. street lamps).

If someone walks through the picture with a sparkler, it leaves an unwanted tail. I quickly hold the box in front of the lens and then pull it away again just as quickly.

After the aforementioned empty phases, i.e. when new rockets are just rising up in the sky, I release the lens again. Curious looks are guaranteed when you use this technique to photograph the next fireworks display together with other photographers.

Or does your digital camera have a (as real as possible) multiple exposure function? Then you can record several sequences of the fireworks in one picture by double exposures and do not have to expose in a whole piece but several times (shorter) one after the other. Of course, a tripod is also essential here.