Whether you got your latest lens brand new or used, it’s a good idea to inspect it thoroughly before using it. Even new lenses can come with scratches, dust or blemishes. Finding out right away if the lens is defective will help ensure you don’t have any problems getting a quick replacement. Here’s everything I do when receiving a new lens.
Inspect the body
Depending on whether the lens you bought is used or new will change what you’re looking for slightly, but the process is still the same. If the lens you bought is new, make sure that it is, in fact, new and not used and repackaged.
Inspect the body of the lens for any scratches and blemishes and check to make sure that any switches on the side of the lens are intact. After looking at the body, take a small flashlight and shine it through the elements and make sure there are no large pieces of dust or other contaminants inside the lens. Even a brand new lens may have a few very small pieces of dust inside it, just make sure there is nothing else.
Clean the lens mount
Examine the lens mount and the connections on the back of the lens. A new lens should have no scratches or scuffs on the metal mount. If there are, it’s a sign that the lens may have been used.
Most new lenses have a small amount of grease on the mount and the rear lens cap. It’s not a bad thing, just part of the manufacturing process. Be sure to take a small cloth and wipe down the rear lens cap and lens mount thoroughly before mounting it on a camera. I forgot to do this with a 35mm lens I purchased last year, and I ended up with dust and dirt stuck onto my camera mount and several of my other lenses. I ended up doing a lot more work than had I just cleaned the lens properly from the start. The last thing you want is grease getting on your camera’s mount or inside the camera and attracting dust and dirt.
Inspect the elements
After you’ve inspected the rest of the lens, take a good look at the front and rear lens elements. If there was a lot of grease on the lens mount, be sure to check the rear element and make sure none got on the edges of it.
New lenses, particularly, shouldn’t have any scratches, nicks, or blemishes on the elements. If it does, send it back for a replacement right away. Even if it doesn’t noticeably affect image quality, it’s better to take care of it now while the lens is new than to wait till later.
If the lens is used or it just has some small oil or dust spots, clean the element thoroughly. For a step-by-step guide on how to clean your lenses, check out this article.
Take some test shots
Now that the lens has been thoroughly inspected and cleaned up, you can attach it to your camera and take some test shots with it. Depending on the type of lens you’re testing, you might find subjects inside the house or you may need to go for a short walk outside.
Try and find several different subjects and shoot from varying distances. Check to see that the lens acquires sharp focus at close distances as well as subjects that are further away. Make sure to listen to the autofocus motor and make sure it is working quickly and quietly with no abnormal sounds.
When you get back to your computer import the images into your software program and see how they turned out. Inspect each image to ensure that your lens acquired proper focus. Although it happens rarely, lenses can be defective. If most of the images you took are very out of focus, you may need to send the lens back for a replacement.
If you’re not sure how far the focus is off or you think it may just need to be adjusted, you can do a focus test to calibrate the lens yourself. This article has a very thorough tutorial and test chart for testing and calibrating your lens.
Most new lenses come with a manufacturer warranty. Nikon offers a 5 year warranty on their lenses and Canon offers a 1 year warranty. I know from experience with Nikon that they will still cover your lens under warranty even if you don’t register it. You will need to provide a receipt showing that you bought it from an authorized dealer. I haven’t bought many Canon lenses new, but I know from friends that own their lenses that even when the warranty has expired, Canon will likely still fix the lens for free (if you ask politely).
Even though registering your lens isn’t required, it’s still a good idea. I have registered all of my Nikon products on their website. When I log in there is a page with all of my warrantied products listed. That way, if I ever have a problem, I don’t need to dig for paperwork and receipts. The information is already saved. With any luck, you should hopefully never need to use the warranty, but it’s nice to know it’s available just in case.
Get a protective filter (optional)
I use filters on all of my lenses. It protects the lens and makes cleaning a breeze. I have lenses that are 20 years old and the front element looks just as good as the day I bought it.
Some photographers will argue that using filters degrade image quality and cause flares and ghosting. This is absolutely true if you buy cheap filters.
Using a high quality filter does not cause any loss of image quality or noticeable flare and ghosting problems. The filters I have been using for years and will continue using are made by B+W. They are the B+W UV MRC (010M) Filters. Depending on the size you need, they cost between $30 and $70, but they’re worth every penny. No matter which filter you go with, be sure to get one that is multi-coated. The extra coating eliminates flare and repels dust and water.