How to Test Your Lens


So, you just bought a shiny, new, and maybe expensive, lens for your camera, and being the savvy consumer, you did your homework. You pored over customer reviews on the B&H Photo website, read online reviews splattered all over the Internet, grabbed a copy of every photo magazine that reviewed the lens, bookmarked dozens of websites, and now have the lens’s MTF curve charts burned into your retinas.

Now, your lens is here and it is time to go out shooting. Honestly, not a problem. Your lens should be as good as it can be and, as photographers, we want to take photos. So, stop reading and go out and make some photographs!

Still here? OK, let me tell you why you might want to test that lens yourself. The main reason is that even with today's precision computer-controlled manufacturing techniques, there are variations in every lens that rolls off an assembly line. This means that some examples will be better than others. Some lenses will be outstanding and others will make you wonder if all of those glowing reviews you read online were completely bogus.

I once purchased a new 40mm lens that was advertised and reviewed to be, based on all reviews, incredibly sharp. The Internet is full of tests that show this is a superb lens. I spent some good money on this lens and hurried home to try it out. However, me being me, I took the new lens out for a shoot with my tried-and-true 50mm f/1.8 lens in the bag. I took the same photos with the two lenses, albeit at the slightly different focal lengths, and hurried home. After analyzing the images, I was left to speculate that, either the reviews are full of lies about this 40mm lens, that I got a bad example of this lens, that my 50mm f/1.8 is the most awesome lens ever made, or a combination of those possibilities.

"I like to test my lenses to determine where in their aperture range and focal range (if a zoom) they are performing at their best."

Had I not had a lens to which I could compare it, I might have been happy with the performance of the 40mm and not known the difference. But, because I did a quick test of my new lens, comparing it to a lens that I was familiar with, I was able to determine that it should be returned to the store and my money saved for something else.

Knowing that no two lenses are the same, as far as performance goes, why else would we want to test a lens? For most of my photography, I want to maximize the sharpness of an image. In order to do that, I like to test my lenses to determine where in their aperture range and focal range (if a zoom) they are performing at their best. A lens’s sharpness and degree of vignetting will change based on the aperture selected, as well as its focal length, if it is a zoom.

Before We Begin

The goal of this article is to give you some pointers on how you can do some basic lens testing at home. To do that, I will share with you techniques I have used to test my lenses. There are two parts to my lens-test goal:

  1. Evaluating the lens’s performance,
  2. Getting the testing out of the way so that I can go out and make photos.

There are a lot of people out there who go absolutely nuts with lens testing. So, if, after you read this, you find yourself building a dust-free clean room in your home, walking around in a lab coat, and trying to figure out ways to shoot laser beams through your lenses onto a computerized target sensor for dispersion analysis, you may want to consider a new career with some of the more well-known lens-testing websites and magazines.

Also, as anyone with an Internet search engine can attest, there are many different opinions and techniques regarding how to test lenses. I generally test my lenses for sharpness. However, you can test for vignetting, symmetry, distortion, focus, and other factors in the comfort of your own home without fancy gear. So, feel free to share your ideas and methods at the end of this article, but please know that what I am sharing here is, simply, my personal technique and I am not suggesting it is the only way, or best way, to test a lens.

Mental Prep

Before we get into the gear needed, you should, if you have it, turn on the part of your brain that may have been lying dormant since grade school science classes. The testing of your lens is an experiment and you need to have a basic scientific mindset to make sure you do not have to go back and repeat the tests over and over again. What do I mean? You need a plan in place before you get started. Have paper and a pencil handy to take notes and refer to the Lens-Test Checklist below. Photography can be done “from the hip,” but good lens testing needs a methodical approach. Don’t worry, we aren’t doing crazy stuff here, just know that a bit of pre-organization and a good plan will make it all go smoother.

Also note that there will not be a “control” for this experiment. If we all owned an optically perfect lens with which to test all others against, we would not have to test our lenses, right? So, your lenses, with their inherent flaws, will either be tested against themselves or other flawed lenses.

Gear Prep

The most crucial piece of gear you will need for a lens test is a tripod. If you do not have a tripod, you will not be able to perform an accurate lens test. Period. No one that I know can handhold a camera completely steadily. Going back to the scientific process mentioned above, we need to eliminate as many variables as possible when performing our tests. Movement is something we need to eliminate in our camera and target. I highly recommend using a remote shutter release (cable, electronic, or wireless), and if using an SLR camera, the mirror lock-up mode to reduce vibrations.

The Targets

I have been told that a famous photographer once said, "I do not photograph test targets.” Well, I do. But, I am not famous. Yet.

There are lots of things you can photograph to get a solid lens test. You can do it indoors or outdoors. You can create your own target, buy a target, or print one from the Internet. You can use what is around you. The possibilities are endless, as are the opinions about what works best.

Full-resolution image available by clicking on the illustration above

Test targets are versatile and can be used for a variety of tests. Some, like the ISO 12233 chart and USAF 1951 Resolution Test Chart, will come up on most web searches. Personally, I located the highest-resolution chart I could download and then I had it printed on photo paper at a big box store at 20 x 30" and dry-mounted on foam core. I was tempted to mat and frame it for permanent display, but all of the wall space in my home was already taken up by photos.

Is a printed test target a perfect target? No. If you want to get crazy, you can spend a lot of money on laser-etched glass targets that are used for calibrating things that are way more precise than your camera and lenses. A printed test target will be your least expensive option.

Some folks will make a homemade diorama with different objects (wine bottles, color charts, tourist trinkets) to photograph in one scene. This is fun and works well for the test, but the problem is, unless you have very understanding roommates or the only key to your photo cave, you will have to put all the objects away when you are finished and you might not be able to recreate it perfectly in the future. The two-dimensional test target gets put away into the closet when I am finished.

Do you need a dedicated target to perform a lens test? No. You can simply go outside and point your camera at something in “real life.”

I kind of cringe when I go to a camera/lens review test website and see photographs of trees as a test target. Why? Well, trees move when the wind blows. Remember what I said about eliminating variables? When I do a lens test outside, I look toward manmade structures (usually stuff that humans make has a ton of right angles and sharp edges) and I try to put lettering of some sort (street sign, license plates, storefront signage) in the center and corners of the image. Remember, you are testing your lens, not creating the greatest photograph on the planet, so don't worry about composition and all the other things that you might usually consider before taking a photo.

Also, you want the things you are going to study in the image to be as close to equidistant from you as possible. When shooting a target on a wall, level your camera and aim for a vertical wall. When outside, try to find a wall or scene in the distance that will have the center and edges of your frame about the same distance away.

I have found that a well-populated bookshelf is a great tool for lens testing. Remember what book you are targeting in the center of the frame and use the writing on the spines of the surrounding books to check your sharpness. Also, the shelves, if straight, can let you evaluate lens distortion.

Speaking of distortion, the “brick wall” is often mentioned in lens-testing circles. Not the worst idea, but I would hope to find one with some signage on it to give me some sharp edges and lines to look at in the images.

If you can do it, I recommend the test target for normal (around 50mm) and telephoto lenses (greater than 50mm) and a wall or bookshelf for wide-angle lenses.

The Plan

Many of us have a camera bag full of zoom lenses and prime lenses. If you have only one prime (fixed focal length lens) to test for sharpness, your mission is simple. If you have a quiver full of lenses and many of them are zooms, you will thank me later for that suggestion to get paper and pencil ready.

For a normal or telephoto prime lens, I simply set up the tripod and camera at the distance where the target fills the frame, and then I take photographs as I run through the aperture settings. When out doing non-lens-test photography, I adjust my aperture in full stops to simplify the exposure math for me. I do the same for lens testing. If you adjust your aperture in half stops or third stops, you will get two or three times the number of test images to sift through and that might be enough to make this process less fun.

For zoom lenses, I roll through each aperture setting (full stops again) at the focal lengths marked on the barrel, which usually correspond to popular prime lens focal lengths (85mm, 105mm, 135mm, etc.). Of course, I will always test the zoom at the widest angle and the greatest, as well, even if they do not correspond to popular fixed focal lengths.

This is where a little planning helps. Say you are evaluating an 85mm f/1.8 prime lens, an 85mm f/1.4 prime lens, and a 70-200mm f/2.8 zoom lens. You can mount each 85mm lens and roll through the apertures, but, before you move your tripod you might want to grab the 70-200mm lens, set it to 85mm, and test at that focal length. Take notes. The image metadata will help remind you what you were doing later, but it is good to have a check-off sheet tracking your progress, so you do not waste time by repeating tests.

Also, if you are testing older, manual focus, pre-electronics lenses, your notes will help you when and if the metadata do not recognize the lens or aperture setting. When I test my manual focus lenses, I try to set up the test so that the targets fill the frame, while allowing me to focus the lens at infinity in an attempt to eliminate focus errors.


Well, you just took several dozen pictures of a test target, bookshelf, wall, or city scene. Now you get to spend some time in front of the computer analyzing the data. I start by renaming the files with the focal length of the actual shot, and the aperture plus the name of the lens. Example: 105mm f8 - Nikkor 70-200 f2.8 AF.jpg. Then, when finished, I can easily compare the shots from a certain lens or a certain focal length by opening just those images on my screen.

Still got your paper and pencil handy? Open a series of images (single lens or single focal length) and start comparing the visual sharpness of the center of the images and the corners. Take some notes. You can also evaluate the images for vignetting and symmetry, as well. For symmetry, verify that the lack of sharpness in the corners is the same for each side of the lens. For vignetting, you can push the contrast and levels sliders to see if the corners darken.

When I compile my notes, I type them up and send the file to myself in an email, saving the notes on my smartphone. Now, when I am out shooting, I can quickly remind myself that my 50mm f/1.8 is slightly sharper in the corners at f/5.6 than at f/8 and that when I go below f/2.8 I start to lose sharpness noticeably.

Mission accomplished. Let us know in the Comments section, below, if you have different proven techniques or questions. Thanks for reading and good luck with your do-it-yourself lens tests!


I found this article while researching "decentered lenses".  I have come to this conclusion: lens manufacturers need to step up their game.  While I understand there will be some variation, I see no reason the consumer should receive a "bad copy" if the manufacturers are indeed using "precision computer-controlled manufacturing techniques".

How is the test different for a video camera? I am checking some lenses on my BMPCC4K. 

Hi Jacquie,

I am not a videographer, so you might want to do some web sleuthing to see if there are specific tests, but you can certainly use my test for your video lenses if you capture still images.

Are you looking to just check the optics or other aspects of video recording?




Nice article, I'm planning to use it to buy a used 18-300 (I hope the owner is patient enough), but it would be nice if you could post an scalable version (PDF, SVG, etc) so we can print it as big (or small) as we can/need.

Hi Juan,

If you click on the test target in the article above, you will be able to download a full-resolution file of that image.

Good luck testing your soon-to-be-purchased 18-300!

Thanks for reading!



I sometimes buy multiple copies of the same lens to test before returning the less-sharp copies.  When shooting the test charts I make a set of Post-It notes, one for each value of each relevant test parameter - which lens copy, aperture, focal length, ISO setting - and swap Post-Its onto a corner of the chart for each test image so that the metadata record becomes part of image itself.  Makes it a little easier to disambiguate bunches of very similar images without the necessity of always consulting the metadata window.

Hey Steve,

I may or may not have done the same thing with multiple copies of the same lens! Don't tell anyone!

Also, the note idea is great. I have used it myself—especially important when testing manual focus vintage lenses that do not register metadata!

Thanks for the tips and thanks for reading!



Do you have a vector version of your BH Test Target? I would scale it up a bit before printing and also used a higher resolution to get sharp edges.

Hi Piotr,

Unfortunately, we do not have a vector version of that target.

I personally downloaded the highest resolution chart I could find online and then modified it in Photoshop with my logo and website to make it my own...if you want to try that!

Thanks for reading!



Nice article. Now, if you please, let's turn the horse and cart around?

I have a shiny refurbished Nikon D500 and a shiny new Tamron 18-200mm lens. Both purchased from B & H. I also have a Nikon D7500 with a 18-140mm lens. I like the D500; however the pictures are not as sharp as with the D7500. I tried both lenses on each camera and the D7500 is the winner. The settings are exactly the same on each camera, and there are no swaying trees or dancing girls. 

By the way, an old term, I'm quite good at taking pictures of bumble bees while in motion. Pictures are not worth their salt, another old term, if they are out-of-focus. Tomorrow morning I plan to run more tests using a Tamron 100-400mm lens.

The fires in Oregon are providing a bit of smoke to you city folks and I apologize for that.

So, what say you?  Any words of wisdom?

Thank you

Hi Edward,

Thanks for the compliment on the article!

OK...turning the rig around 180 deg...

Based on the facts you have laid out, my hypothesis would be that the D500 needs a microfocus adjustment.

Let me know how my guess is sitting with you and, if you find that is the culprit.

It is nice to see another APS-C shooter out there that isn't falling for the full-frame propaganda. the D500 is an amazing machine...I hope it starts behaving better!

Thank you for shopping at B&H and thanks for reading!

Standing by for follow-ups/results.



Thanks for this article. I have a few Panasonic MFT lenses that I am going to try out on the top of the line Olympus MFT.

The GH-3 I bought them for is 12MP. The Olympus is 20MP. Not only that, I have been spoiled with some high quality Nikon glass over the intervening 8 years. These are not top quality lenses.

I just need to know if I can use them without feeling like I need to replace them immediately with better glass.

We'll see how it works out. 

Hi Steven,

You are welcome for the article!

In my experience, both Olympus and Panasonic make some exceptional glass for their Micro Four Thirds cameras. I am curious as to what you find in your tests!



I may never test a lens, but I loved reading this article. It was playful, fun, and very informative

Hi Abhinav,

Thank you, so much, for the kind words! I am glad you enjoyed the article!

By the way, testing lenses is more fun than reading articles about testing lenses! Give it a try!



Does B&H offer a checklist (as you stated) for camera testing? I have the new RF 100-500 and I have yet to get a sharp image on the R5. Going to try the Canon R with the lens today. 


Hey Martha,

I can add a checklist for my method...but give me a few days!

The article does go through the steps in a non-concise manner! :)



OMG I purchased TWO Canon  R5 bodies, tested both. I kept hearing how amazing they were. I got one & it sucked. So I sold it and got another thinking maybe I got a lemon. It sucked too so I returned it. I have owned Mark 4, 5 DSR, 1Dx II & been in business a decade all Canon products. The R5s that I got were terrible. Noisy, unimpressed with the sharpness. I heard all the rage about how good they were & I drank the kool aid - twice. They still have work to do on this camera. Glad to hear I’m not the only person underwhelmed by their performance. Could have just burned a pile of cash for all that waste.

Hi Carol,

Sorry to hear about your experiences with the R5. That is very interesting and I will keep that information in my head when talking to folks looking for a new camera.

I hope Canon is working on remedying this.

Thanks for reading!



I'm a firm believer in using a flash to make sure all movement is eliminated. I've done a video with details. [Link removed.]

Greetings, do you do these test shooting in RAW or JPEG?

Hi Scott,

Great question. You can use either raw or JPEG files for the tests. I have done both and, if I am thinking about it, I will switch to JPEG just to make the file sizes more manageable.

I am sure some will argue that JPEG compression will effect resolution, but you really have to be literally splitting pixels to see a difference and that is beyond what your eye will be seeing when comparing the sharpness of your lens(es) at different apertures.

Thanks for reading!




Actually, it's better to shoot RAW for these tests if you can. The reason is that your camera may apply lens correction routines for certain lenses when in JPEG mode, but not in RAW mode (except for the built-in JPEG preview possibly). For example, my Pentax K-1 II does this for most Pentax branded DA and D FA series lenses. You can also turn the lens correction off in the camera menus, though. The lens correction may make it more difficult for you to find out where your lens is actually problematic. It also makes it more difficult to compare different lenses at the same focal length, if one has lens correction applied and the other does not.


Hey Julien,

Great point there! Now that I think about it (thanks!), you are correct. I did not consider the JPEG manipulation that happens in-camera as far as distortion and sharpening.

Thanks for reading Explora and helping make us better!



There's no guarantee that whatever application one uses to view raw files won't also apply automatic lens correction, though. You never really see "THE raw file" on your screen, you only see one of a near countless number of possible interpretations of it using whatever settings are current in the raw conversion application being used.

Hi Michael,

I won't disagree with you there and your point is probably more correct now than it was when I wrote this article and when I was doing tests with my Nikon D100 way back when! Many modern digital cameras are applying corrections that you 1) don't know about and, 2) cannot really take control of.

Will that affect a lens test? Yes, probably. Can you still learn from the tests and see variations in each image as far as sharpness and aberrations? I believe you can. Are we talking about super-scientific testing here? Nope.

Bottom line is that I think this is still a valid way to learn about the performance of your lens(es) and apply that knowledge to how you employ said lens(es).

Thanks for reading and commenting!



Any tips for a novice on testing for adjusting speedboosters for infinity focus???

To our knowledge, speed boosters do not affect infinity focus. If you're having a specific issue with a speed booster that you own, we invite you to contact us via Live Chat on our website until 8PM ET this evening so we can discuss the issue in further detail.

This is a great reference. Are there any good techniques for testing macro lenses?

You could apply the same method mentioned in the article to macro lenses as well.

This is a fine article.   I used it to test a Nikon 12-24  vs. a Ziess Distagon 18mm.  I set the 12-24 at 18mm.  I shot a rack of electronics at about 8ft in both Raw and JPEG.  I am wondering, due to a comment in one of your responses:  I shot all of the test at f8  on a tripod.  I shot landscapes always on a tripod and at f8 and up.

I really can't see a difference in sharpness when viewed on my monitor at 100%.  Is this because I shot at f8?  and if I always shot at f8 and higher will a lens make any difference?  I know the Nikon is a fine lens, but I expected the Ziess to be better (prime, and $$)


Thank you.


sorry  the word shot should be shoot in two instances here.

Hey Dale,

Thank you for the kind words about the article! I am glad you enjoyed it.

You hit the nail on the head here in many ways. At f/8 (or maybe f/5.6) the differences between a super-expensive premium lens and a kit zoom will be really only visible to pixel peepers or seen in gigantic prints viewed at close range (because that is how everyone looks at big prints!).

The Zeiss 18mm is likely sharper at wider apertures than the Nikon as prime lenses have that advantage over zooms. Also, you could see a difference in distortion and things like chromatic aberations as well, but sharpness at mid-apertures will always be close.

Beware the argument that says, "Well, if you zoom in to 200% you can see the difference." That is not a real-life comparison as no one views prints (or even photos on the web) at high magnification.

Let me know if you have follow-up questions and thanks for stopping by!

Great article. I have a Nikon D610, I bought a used Nikon AF 28-105mm 3.5-4.5 D lens. The lens is great optically, but I noticed the focal length information is not accurately displayed, it always reads 75mm. I was wondering if the lens is defective or if this information is not sent from this lens to the camera.  Your help would be appreciated. 

Hey Glenn,

Thanks for the question and kind words!

The short answer is, "I have no idea!"

I would speculate that there is an issue with the electronic connections between the lens and camera. Sometimes you can clean them up a bit with a pencil eraser or by using other means, but usually the connections work or they don't. This seems like a specific failure. Of course, other information might not be being passed between lens and camera, but it is not "visible" to you.

I would try to clean your contacts and then, if it bugs you a bunch, send it in for repair. If the lens is optically performing and the aperture and focus are all good, I would be tempted to ignore the metadata coming off the lens.

Good luck!

If a lens will not focus properly at the infinity marking, does this mean the lens doesn't fit far enough into the camera body or just the opposite?

Hi Sam,

Are you saying your lens will not reach infinity focus? Meaning, when focused at the infinity mark (or beyond), distant objects like stars and planets and mountain ranges are still blurry?

Many lenses focus past the infinity mark, so be sure you haven't passed infinity and started to defocus on the backside of that "distance."

If you cannot manually focus at all on very distant objects, regardless of the position of the focus ring, then there is an issue with the lens (most likely) and/or the camera mount (unlikely unless the camera was damaged) that will require testing and repair.

For more on infinity focus, check out this article:

Let me know what you discover or if you have amplifying information.

Good luck!

Todd:  Thanks for this great article.  I have a Nikon 16-35mm f4 VR lens with which I have noticed apparent asymmetric focusing; one side (not corner) consistently softer than the other.  I will take further test shots but if confirmed I am obviously concerned about malaligned optics.  If the latter is the case, may I assume that this problem can be corrected?  If so, is this best done by Nikon or are you aware of any companies that specialize in lens alignments.  Thanks again

Hi Aaron,

Thanks for the kind words!

That definitely doesn't sound like something you are going to be able to correct with contact lenses or split filters!

Your options are sending it back to Nikon or sending it to your local camera repair store (depending on where you live, there might be one). There are a few repair places in New York City and you can certainly call them and ask if they have the capability of fixing that repair.

Also, check your warranty paperwork from Nikon and give them a call to see if you are still covered.

Good luck and let me know if you have more questions! Thanks for stopping by!

Thanks. No major camera shop nearby.  Probably will need to send to Nikon.  Appreciate the help.

Hi Aaron,

You could contact repair centers in other towns to see if they work through the mail...depending on what Nikon says, you might want to investigate this to save some money.

Good luck!

Hi Todd: Thanks for a very helpful article. I have a question: after taking all the shots and comparing, how large of the image usually to magnify to view in Lightroom for sharpness?     1:1 or 2:1 or 3:1. Thanks.

Hey william,

First of all, thanks for the kind words! I am glad you enjoyed the article.

Secondly, great question! There is no right or wrong here, but I just checked my LR and I go to 1:1. I believe that is "100%" and that would be similar in Photoshop. You can get closer, but my feeling is that, if you zoom in more, you'll only be racking up credits for a graduate degree in Pixel Peeping and that degree gets you into even less doors than an MFA!

Todd, I am following your procedures to conduct an experiment.  I am trying to confirm that an APC lens (borrowed Canon EF-S 15-85 f3.5-5.6 IS) would have higher image quality than a Full Frame lens (Canon EF 24-70 f4.0) on my crop sensor (Canon 7D) body.

The plan is to shoot both lens over their similar focal lengths at the 24, 35, 50, and 70 for each f5.6, 8, and 11 appeture.

The question that remains is the focus method.  Do you rely on Auto focus? If so are the lens auto focus "fine tuned" using the custom function III-05: Fine tuning your Autofocus lens for each lens?

Do you manually focus on the chart?

Do you use "Live View" to achieve focus?

Thank you for any guidance that you could provide.

Nick Vitillo

Hey Nick,

Sorry for the delay in replying...I was out of town last week.

Great question(s)!

So, for auto focus lenses, I usually use the auto focus when doing the lens tests. If I get an un-sharp image at sweet spot apertures, then I would speculate that I had an AF error, or kicked the tripod.

My recommendation would be to test both lenses with auto focus on. If you don't get good results, try a round with manual focus and, yes, I would recommend Live View to assist with accuracy there as the days of awesome split prism focus screens are mostly gone.

My guess is that the 24-70 will be sharper around f/4...but at f/8, it will be harder to tell them apart regardless of the focal length.

Let us know what you found! Thanks for stopping by and, again, sorry for the delay in replying.

A whole shelf of books about Nixon ?  What's up with that ?


I'll have to ask my old is his bookshelf!


The target image is only 72dpi, if i would print this the quality in not very good. Is not possible upload a 300dpi version?


Hey Mick,

The original file is the same you have it at maximum resolution. It should be sufficient for testing.

The well known ISO 12233 charts can be found online and they are at similar resolution in .pdf form.

Sorry I am not more help, Mick!

Welcome! Good luck!

FYI, after I wrote this article I modified the ISO 12233 chart with my website and "company" logo...pretty fun to make your own test target!

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