A used lens camera can be a cost-effective way to add quality glass to your kit. Just be sure to inspect it carefully before making a purchase.
If you buy from a camera store or reputable online retailer you can return the lens if it doesn’t work for you. But if you buy from an individual on eBay or Craigslist your options are more limited.
Check the condition of the lens
The condition of a lens is an important factor to consider. Small scratches on the body aren’t much of a concern and shouldn’t impact image quality, but dings and dents are a red flag. Also, examine the screws and rubber pieces holding the lens together – any evidence of disassembly or reassembly could be an indicator that there have been mechanical problems in the past.중고렌즈
Shine a flashlight through the lens and look for fungus, dust particles, and scratches on both sides of the glass. Check the mount for signs of damage, and be sure all the electronic contacts are clean. These are responsible for the lens’ communication with the camera, and corroded pins can cause communication errors and aperture control issues. If the lens has a UV, clear, or protection filter attached, ask the seller to remove it. Removing it accomplishes three things: it gives you a better look at the lens, demonstrates that the threading is in good shape, and gets rid of an unnecessary filter.테크노마트카메라
Test the focus and zoom rings
If the lens is for a camera with a viewfinder, check that it zooms smoothly and the focus moves without a bump (listen and feel) and a noticeable resistance (the action should be damped). Look also for cracks in the filter ring (not crucial but damage can indicate rough usage).
Examine the rubber pieces that hold the lens together, especially around the mount. Marks here can indicate a lens has been taken apart and reassembled, which will reduce its resale value.
If the lens has image stabilization, test it by attempting to take several handheld photos with the feature enabled and then a few with it disabled. This feature can make a big difference in some circumstances, so it’s worth checking. Also check that the lens’s AF switch works and is not stuck.
Check the focus ring
On modern lenses there are electronic contact points at the back that facilitate communication with the camera for auto focus and aperture control. They’re usually gold and if they’re dirty or corroded it can prevent the lens from communicating correctly with the body and cause problems such as incorrect aperture settings and no auto focus.
Examine the lens for signs of coating wear, which looks like oval-shaped scratches about a finger’s width from the edge of the glass. Also look for any evidence of lens element separation, which is hard to fix and can ruin the image quality of the entire lens. Buying from a reputable camera store or lens dealer is best since they’ll thoroughly inspect and test the equipment before selling it.
Check the focusing ring’s smoothness
The focusing ring on the lens (and zoom and aperture rings, if present) should be smooth to move and feel dampened to your touch. If they are stiff or make rattling noises, it may be time to pass on this lens.
If possible, have the seller let you mount their lens on your camera and test it out. This way you can see how the lens feels and if it will perform properly with your system.
Look closely at any photos the seller has of the lens. Make sure the glass is clean and doesn’t show signs of fungus, haze or mold. Shine a not-too-bright flashlight through the lens to check the front and rear elements for any scratches. Scratches on the front element are more likely to affect image quality than those on the rear.
Check the glass
Especially on older lenses, examine the glass for blemishes and scratches. Even a few minor scratches can affect the quality of a lens dramatically. Look at the front and back elements from an oblique angle.
Fungus and water spots are another common problem with used lenses. If you find them, avoid purchasing the lens and instead seek a replacement.
The electronic contact pins found on the back of modern lenses facilitate communication with the camera. Make sure they are clean and don’t exhibit signs of corrosion. If they are corroded, it’s likely that they will eventually wear down the thin gold-plating and cause problems with aperture control, autofocus, image stabilization, and other lens-related data. If the pins are corroded, they may need to be replaced.