A Guide To Buying A Used Lens :: Digital Photo Secrets

A Guide To Buying A Used Lens

by David Peterson 5 comments

Thinking about purchasing a used lens for your digital SLR? It can be a risky game. Sure, the price is lower than retail, but you also have to deal with the wear and tear the previous owner put the lens through. Because none of has the time to test every little detail on a used lens, I’ve broken it down into an easy to follow guide. If you are looking to purchase a used lens, make sure you do these tests first.

Check for problems with images taken with the lens

This is the first thing I check. Sometimes the outside of a lens looks fine, but the optics inside have been damaged by a fall. The quickest way to test is to take a couple of test shots. It helps to take a photo of an object with a straight line (like a fence, or a wall). If the lens is slightly out of alignment, these straight lines may not be as straight on the image. Take these shots while directly in front of the the object to minimise any distortion that can come from a perspective shot.

Check for scratches or small dents on the outside of the lens

You first want to find out what kind of abuse this lens has been put through. Has it been dropped before? A scratch or small dent on the exterior is a good sign the lens has been dropped. If you notice either of these, ask the seller how the damage happened. Anything you can do to get more information will help you make a better purchasing decision.

Twist the lens and flip the switches on the sides

Check to see if the switches perform their functions, and make sure you do it using your own camera body. Twist the zoom and focus rings to see if there is any resistance. Sometimes sand gets caught in these parts of the lens, resulting in a slow kind of wear and tear on the internals. If you hear any weird noises, take note of them and ask the lens owner what may have caused them.

Test the front and back lens connectors

Take the lens off of the camera it is mounted to, and look for any scratches on the underside where it connects to the camera body. Also take a close peek at the gaskets and note any rust or corrosion present. Sometimes water gets into these connections, and it’s all downhill from there. Make sure you bring a U.V. filter with you so you can test the threads on the front of the lens. If it’s relatively easy to attach filters, that’s a sign that the lens is still in good condition (i.e. it wasn’t dropped, causing dents on the threads).

Mount the lens to your camera

I always make sure I mount and unmount the lens to my camera. I do this a few times, checking the strength of the connection while listening for any sounds that might be out of the ordinary. A good lens produces a noticeably audible “click” sound when it is attached to the camera body.

Check the focus/autofocus capability

Mount the lens to your own digital SLR, and play around with the autofocus. Note how quickly it responds, and whether there are any strange noises (noticing a theme here?). Autofocus should make a slight noise, but once it becomes long a drawling hissy sort of noise, there’s likely an issue with the AF mechanism. Compare the noise to your other lenses if you need a reference.

At this point, you will also want to test the accuracy of your autofocusing system. Find any object with protruding text, and focus on that (your lens cap is a good one as you always have it on you). Next, focus on a letter and take a picture. Look at it closely in review mode to see if there are any strange looking color bands (a.k.a. chromatic aberration) or other oddities like bent areas. Each of these reduces the value of the lens.

Check the aperture settings

This one is a little challenging, especially if you don’t know what you’re looking for. The electronic aperture on a lens is the little hole that light travels through to make an image on the sensor. Every time you adjust the aperture up or down, this hole shrinks and grows. To see if it’s working properly, you need to switch over to your camera’s “depth of field preview” mode and then watch as your aperture adjusts itself for each setting (not all camera models have a depth of field preview mode. Consult your camera owners manual or online documentation to find out if yours does).

Those of you looking to purchase a strictly manual lens will have a much easier time. You only need to look at the aperture while adjusting the settings on the lens itself.

Lastly, when you purchase used lenses, understand that there’s really no need to be paranoid about every detail. If you’re getting a bargain on something that would have otherwise cost you a fortune brand new, just go for it! There is such a thing as “good enough,” even when you make your living as a photographer.

Most people think this post is Awesome. What do you think?

Comments

  1. Clive Brodie says:

    Thank you very much for the;Guide to buying a used lens.Very informative.One takes certain things for granted when buying a seond hand lens.

  2. Pat Cove says:

    Please don't forget to look for mould on the inside of the lens! You can tell the best way to look for this, but I just hold the lens in front of a light source like a window and move it around. It will be quite obvious if there is any, like a sort of spider web.
    P.

  3. Shashikant says:

    Hi David please allow me to add that even a brand new lens if not used or used after a long gap also behaves sluggish and erratically. while the lens/es which are used regularly do not face such problems. I faced this problem with my lenses (all Nikon). My 18mm - 135 mm and 70mm - 300mm lenses worked very well in my trip to Himalayas at -10 degrees centigrade at 18500 feet altitude but 105mm ID AF ED VR macro lens was behaving funny because I tried to use it after long storage after 6 months. This lens became ok after repeating several operations in the camera.

  4. Nick says:

    What are your thoughts about mirror lenses.

  5. Basil Rohald says:

    I recently bought a 100mm Macro 2.8 Canon lens and a 28-135 SIGMA lens for my Canon camera from

    what I thought was a respected dealer.

    Before purchasing I tried both lenses out on my camera and they seemed to work O.K.

    However after a few weeks both lenses kept on giving me blurd pictures and auto focus on both

    would not work properly.

    Wish I had read such an article as the one you have written earlier.

    I call it a case of penny-wise and pound-foolish.

    A bad move on my part.

Leave a Comment

Your email address will not be published. Required fields are marked *

Difficulty:
Beginner
Length:
6 minutes
About David Peterson
David Peterson is the creator of Digital Photo Secrets, and the Photography Dash and loves teaching photography to fellow photographers all around the world. You can follow him on Twitter at @dphotosecrets or on Google+.