December 14, 2011

What Lens Should I Choose?

Confused by all those numbers? Not sure which lens best fits your needs? Here’s a breakdown of what all those numbers attached to an SLR lens mean. If you’re thinking of adding a new lens to your camera this year, this quick cheat sheet will help you pick the right lens for your needs.

18-55mm f/3.5-5.6

Here’s a standard lens we can use as an example. This is the kit lens that comes with the Canon Rebel T3i. If you’re not sure what you’re looking at, this might as well be written in a foreign language! First of all, here’s how you say it: 18 to 55 millimeter F 3.5 to 5.6. Now let’s break it down.


This is your Focal Length. Focal Length is how far your camera will zoom in and out. The lower the number, the more you can fit in the photo. In other words, this is how much you can zoom out. The higher the number, the more it zooms in. The lens above will zoom from 18-55mm. 18-55 is a great focal length for an all purpose lens. My all purpose lens that hardly ever leaves my camera is 24-70mm. To give you a point of reference for what 18-55mm means, here are some examples of a few other focal lengths.


This is considered a Wide Angle lens. This lens will zoom out more than the 18-55mm lens. I use this lens when I want to fit a lot in the picture, but don’t have a lot of room to “back up” and fit everything in. A wide angle lens is great for traveling. I use mine to photograph hotel rooms, scenery, and city skylines. I can fit a whole lot in the photo without having to be too far away from my subject.


Lens 10-22mm f/3.5-4.5
Focal Length 10mm
Aperture f/3.5
Shutter Speed 1/15 sec


Lens 10-22mm f/3.5-4.5
Focal Length 10mm
Aperture f/8
Shutter Speed 1/15 sec


Lens 10-22mm f/3.5-4.5
Focal Length 10mm
Aperture f/5.6
Shutter Speed 15 seconds

However, due to distortion and lack of background blur, I would not recommend a wide angle lens for portrait or food photography.

70-200mm (and above)

This is considered a Telephoto lens. This lens zooms in more than the 18-55mm. I use this lens for outdoor action photography. Because it zooms so far in, I don’t know that I’ve ever used this lens indoors. With a 70-200mm lens, you would have to be pretty far away from your subject to fit it in the photo, which is why this lens is best for outdoors or indoor arenas with lots of room where you would want to zoom in. I use this lens for outdoor action shots of Miley and Howie.


Lens 70-200mm f/4L
Focal Length 104mm
Aperture f/4.5
Shutter Speed 1/1000 sec

A telephoto lens is great for outdoors, action, and candid portraits — any subject which you can be pretty far away from and still photograph. I do not recommend a telephoto lens for everyday indoor photography.


If a lens only has one number it’s called a Prime or Fixed lens. This means the lens does not zoom in and out at all. I could not comprehend this until I got my first fixed lens! I did not know how it could not zoom at all. But it doesn’t. Imagine a cellphone camera without a zoom. If you want to get further away from or closer to your subject, you’ll have to move with your feet.


Lens 50mm f/1.4
Focal Length 50mm
Aperture f/1.6
Shutter Speed 1/500 sec

Prime lenses are great for indoor, outdoor, portrait and food photography. Their only limitation is in their lack of zoom.

So that basically covers your focal length. If you already have a lens, look to see what the focal length is, and take note. Do you like the focal length? Do you wish you could zoom in more? Zoom out more? If you want to zoom in more, look for a lens with higher numbers than what you have. If you want to zoom out more, look for a lens with lower numbers. If you’re pretty happy with the focal length, look for a lens with similar numbers. If you don’t already have a lens and you’re not sure what focal length you need, I would consider a lens within the range of 17-100 to be a great focal length for an all purpose lens.

Now on to aperture.


Let’s go back to our example lens, the 18-55mm f/3.5-5.6. The aperture on this lens is f/3.5-5.6. Aperture controls the background blur, or bokeh, in your photos. The lower the number, the more background blur you can achieve. You’ll notice that this lens has two numbers, 3.5-5.6. That means that when the lens is zoomed all the way out (18mm), you can set your aperture as low as 3.5. But when you are zoomed all the way in (55mm), the lowest you can set your aperture is 5.6. If you have a lens with just one number here, for example, the 24-70mm f/2.8, that means you can set your aperture as low as 2.8 no matter how much you are zoomed in or out. Keep in mind that the aperture numbers on the lens are simply the lowest the aperture can be set. On both lenses your aperture can always be set higher, no matter what your focal length is.

To make things even more confusing, the amount of background blur created by the aperture is directly proportional to the focal length. The higher your focal length (the more zoomed in your are), the more background blur you will have. For example, a photo with an aperture of f/4 and a focal length of 18mm will not have much background blur. However a photo with the same aperture of f/4 and a focal length of 200mm will have a substantial amount of background blur. Notice the two photos below have the same aperture of f/4.

Tons of background blur here.

Lens 70-200mm f/4L
Focal Length 200mm
Aperture f/4
Shutter Speed 1/640 sec

No background blur.

Lens 10-22mm f/3.5-4.5
Focal Length 17mm
Aperture f/4
Shutter Speed 1/2000 sec

If you want deep, soft background blur at an all purpose focal length, I would not recommend getting a lens with anything higher than 2.8. One other important thing to note: If you want any type of background blur, I would not, under any circumstances, recommend a lens with more than one number in the aperture value. Take our example lens above, with an aperture value of 3.5-5.6. At 18mm, f/3.5 just isn’t a low enough aperture to give you background blur. Likewise, at 55mm, f/5.6 isn’t low enough to produce a soft background either. However, if you could set your aperture as low as f/2.8, you could generate plenty of background blur at a focal length of 18 or 55.


Lens 24-70mm f/2.8L
Focal Length 24mm
Aperture f/2.8
Shutter Speed 1/30 sec

Lens 50mm f/1.8
Focal Length 50mm
Aperture f/1.8
Shutter Speed 1/2500 sec

Look for a lens with a versatile focal length with only one number in the Aperture area.


One other lens to note is a macro lens. If you find yourself constantly wanting to get up close and personal with your subjects, wishing you could zoom in closer for details, or cropping your photos closely once you get them on the computer, you may want to consider a macro lens. A macro lens lets you zoom in close to your subject and focus on the details so you don’t have to crop your photos or zoom in on the computer. Cropping on the computer only degrades the quality of the photo. Macro lenses are also great for portraits, and depending on the focal length you chose, a general all purpose lens.


Lens 100mm f/2.8 Macro
Focal Length 100mm
Aperture f/2.8
Shutter Speed 1/160 sec

What I’m Using

Here’s a breakdown of the lenses in my arsenal, along with how I use each one.

24-70 f/2.8 L

You’ll notice this falls in the all purpose focal length, with a nice, low, and singular aperture number. This is my default lens. I use it for travel, portraits, and food photography. A great alternative to this lens to consider is the Tamron 17-50mm F/2.8. That’s the lens I used for years before upgrading to the Canon 24-70 lens. The photo below was taken in 2006 with a Canon XTi with the Tamron 17-50mm F/2.8 and is SOOC — no editing. At just over $400, this lens is a great deal.

Lens Tamron 17-50mm F/2.8
Focal Length 50mm
Aperture f/2.8

10-22 f/3.5-4.5

This is a wide angle focal length, and since background blur is pretty much nonexistent at such a wide angle, I don’t care about the aperture number here. I use this lens for travel, scenery, city skylines, and hotel rooms.

50mm f/1.4

This is a fixed lens with a very low aperture. This lens produces excellent bokeh! I use this when I want a ton of bokeh, or in low light when I need to use a lower aperture in order to steadily hand hold the camera. I talk about this more in depth in my Quick Guide to Understanding Your DSLR post. Another lens to consider is the 50mm f/1.8. Super cheap and super fun. You’ll get great bokeh with either of these lenses. They’re perfect for portraits, food photography, and because of the middle-of-the-road focal length, even travel.

100mm f/2.8 Macro

This is another fixed lens with a great low aperture. It’s a macro lens, and the background blur is excellent. This lens is fun for portraits and food photography. I use it when I want to zoom in super close on the details or get tons of background blur.

70-200 f/4 L

This is my telephoto lens, and I mostly use it outdoors to get action photos of Miley and Howie. The aperture is not super low, but since the focal length is higher, I’m still able to get great background blur.

Final Notes

The full name of our lens above is actually EF-S 18-55mm f/3.5-5.6 IS. The focal length and aperture numbers described above are the most important factors when choosing a lens, but just in case, here’s what those other numbers and letters mean.

EF or EF-S. This refers to the lens mount. EF is the standard lens mount on Canon EOS DSLR cameras. This is indicated by a red dot on the lens that corresponds to the red dot on the camera where you attach the lens. If your camera also as a white square, you can also accept lenses with an EF-S lens mount.

L. This indicates the lens is a top-of-the-line lens from Canon, also known as a “Luxury” lens.

IS. IS stands for Image Stabilization. Many of the available lenses will come both with and without an IS option. I always opt for the cheaper, non-IS version because I have a pretty steady hand. However, if you have a shaky hand, this might be an option to consider.

With this information you are now armed with the knowledge to confidently purchase a new lens for your camera! If you have any questions, I’ll be happy to answer as best I can. Just leave me a comment below. Happy shopping!

See More Posts About: Photography Tutorials


Zina November 28, 2012 at 4:27 pm

This is probably the BEST lens guide I’ve seen! Nope….definitely. :D I appreciate it and I have a lot to think about! I thought surely I would add the 100mm to my gear (as I have a 50mm f 1.4 and 1.8), because I thought I could kill 2 birds with it- food and portraits. But I also need to be able to photograph the kids in a pic together at least once before they get old. lol Now, because of your beautiful shots and in-depth advice, I am leaning toward the Tamron 17-50 and the Canon 10-22mm together instead of the 100mm. Does that make sense? Or am I missing any key factors based on my needs? I have a bday coming up in 2 weeks so I need to be ready when the hubby asks… lol

Thank you again! Be Blessed!



Jay January 16, 2013 at 11:58 pm

Have to agree with so many previous posts. Great concise, manageable summary of lenses and what to look for. I’m shooting a Canon 600D with the 18-55 and 55-250 kit lenses. I also have the 50mm 1.8 and love it. I take everything from inside portraits to outdoors and backyard birding shots. Have an upcoming trip to Jackson Hole and am looking to add to my collection before my trip. I am willing to pay for good glass although can probably only afford one more lens at this point. After reading your article, I’m trying to decide between the Canon 17-55mm 2.8, the Canon 10-22mm, or the Canon 100-400mm 4.5-5.6L. Originally I was looking for additional focal lengths to what I currently own, but perhaps I should upgrade quality instead. Any thoughts would be great.


jane February 14, 2013 at 12:12 pm

can you tell me how i find the size off lens to fit my sony a57 thanks jane


Sally February 20, 2013 at 12:15 pm

I have been looking for a break down that I could understand. Thank you for taking time to do this. It helped me a ton!!


Pam February 24, 2013 at 10:21 am

Thanks for this detail post Amanda!!
I’ve a question- are all your recommendations on a crop sensor camera or full frame? What camera body do you own?


Jeanette Branham February 27, 2013 at 3:58 pm

Thank you for such an educational website. I just upgraded from a 6 year old Canon Rebel (that still works btw) to a new Canon 60D and am very intimidated but determined to learn how to use it. This site is just what I needed to do just that. Again thank you so much :)


Meaghan Murphy March 4, 2013 at 3:59 pm

Hi Amanda! Such a helpful post. I am interested in the 17-100mm you were talking about. Do you have any specific recommendations or even links? I can’t seem to find it online. Thanks!


Marla Freeman April 3, 2013 at 1:31 pm

I have Cannon 2si. I use kit lens primarily. Would a Tameron 10-24 give me a better landscape picture. Is it worth the $500? Is it a good lens for the money?


Gerrie April 29, 2013 at 4:45 pm

I am a novice and I was given this lens. When would you use this lens: Sigma DG 70-300mm 1:4-5.6. Thanks!


Gerrie April 29, 2013 at 4:48 pm

Haha! Nevermind. I just read about it in your tutorial. Thanks!


Blondebimbo April 30, 2013 at 1:24 pm

Hi, Amanda

As the name implies, I know nothing, and would love to take up photography. I am going to Vietnam and Cambodia, later this year, and am looking fo a lens to encapsulate places like Halong Bay.
I have a Nikon D3100 camera, and would much appreciate some help.


Blondebimbo April 30, 2013 at 1:25 pm

Sorry, forgot to say I am looking for a lens, I already have 18-55m Thanks

Kelley May 7, 2013 at 2:14 pm

Hi there! I am about to take some photos for a friends. Outdoors with solid White barn backdrop. What lens do you recommend I use? This will be for marketing in her salon. I have a Nikon D3100. was thinking about renting Nikon 70-300mm f/4.5-5.6G AF-S IF-ED VR


Simone May 7, 2013 at 5:12 pm



Shundara@ SavyNaturalista May 14, 2013 at 11:55 am

Great post! I am looking to buy a lens and had know clue what I was buying but you just made id so simple thanks!


Sharin Shank May 21, 2013 at 7:17 pm

Hi! I see that you have a Canon 70-200 4L. There isn’t IS on this lens. How do you do with it? I am a portrait and wedding photographer and am saving to buy the 70-200 lens. I just don’t know which one! It is a big investment. If I could get away with getting the 4L, I would totally buy it today!!!

Please share your thoughts. Thanks so much!!

Sharin Shank


Sharin Shank May 21, 2013 at 7:17 pm

Hi! I see that you have a Canon 70-200 4L. There isn’t IS on this lens. How do you do with it? I am a portrait and wedding photographer and am saving to buy the 70-200 lens. I just don’t know which one! It is a big investment. If I could get away with getting the 4L, I would totally buy it today!!!

Please share your thoughts. Thanks so much!!

Sharin Shank


Amanda May 22, 2013 at 12:40 pm

Hi Sharin!

Can you rent them both and see which one you prefer? Since it is your business, I would definitely recommend getting the best glass you feel comfortable investing in. :) To be honest, I have never used an IS lens, but I do most of my shooting outdoors in full light, so I have never missed it. If you are shooting indoors or in low-light situation, an IS lens might be worth the investment! :) Hope this helps! :)

Danica May 30, 2013 at 5:16 am

Wow, this is the best article on lenses I have ever read! Very to the point, but with just enough information. Thanks!


Oriee June 12, 2013 at 4:02 pm

Wow wow wow, Oh my Godness!!
This is such an amazing article! I’m so grateful for you.
Finally I’m able to understand exactly the meaning of the information on lens barrel (especially the fixed F number)…

One question please, do you have any idea about Sigma 24-70mm f/2.8 IF EX DG HSM whether it’s a good deal or not, or may be Tamron is better?

Thanks again.


Erin @ Texanerin Baking July 14, 2013 at 3:31 pm

I’ve already bought the Tamron 17-50mm F/2.8 and 100mm f/2.8 Macro based off of this page and I’m about to buy a third lens on here (the 50mm 1.4 because I just broke the 1.8)

Too bad I couldn’t buy any of these lenses in the US. You’d have made quite a bit of money off of me. :D


Aanand August 3, 2013 at 2:51 pm

Hello Amanda,
Your article is awesome and you made it so easy to understand. Especially with the pictures.
Could you please explain ‘Shutter Speed’ .


Suman September 7, 2013 at 12:19 am

Hi. This is a really good article. Really simplifies all the details about lenses. Thank you so much. I had a question though.
I am pretty new to photography and I have the basic nikon 18 to 55mm lens and managed to pick up a 50mm f/1.8 manual focus lens. I am not a photographer but for general portrait would you recommend me to buy a 85mm f/1.4 if I am getting it cheap? Would it make much of a difference from the other prime lens that I have?


Anne October 16, 2013 at 7:05 pm

Love this post! So if you could only have one new lens (I already have a 50mm 1.8) would it be the 50mm 1.4, 85mm 1.8 or 100mm 2.8?


Mindy November 6, 2013 at 2:45 pm

Hey Amanda!
I’m not a professional photographer but I’ve been taking pictures for over two years now. I have a Nikon D5000 and use a 50mm 1.8 lens. I want to upgrade my camera and lens and would LOVE some suggestions! I only shoot outdoors right now. Mostly family, children, couples, seniors, etc. I would also like something (a new lens) for indoors for baby showers, birthdays, & holidays.
I’ve thought about getting a full frame camera as my upgrade. Any input would be greatly appreciated!! Hope to hear from you!
Thanks so much! :)


Kat November 16, 2013 at 8:50 am


I am just getting into blogging and photography. Although photography has been a passion of mine since I was a child, it’s just now that I’m getting into more detailed photography. This post and another one you did has made this so easy to explain. Thanks for that! Hopefully one day I can do as well as you!




Adelle November 25, 2013 at 3:23 pm

Thank you for this post, it has helped me understand the basics :)
So i am thinking of buying a new lens for my nikon d3100, amd am not exactly sure what i should buy, there are just way too many lenses out there :) so at the moment i was looking at the 50mm 1.8 or 1.4. My first question is, is it worth it to buy the 1.4 for double the price? The primary things i would like to photograph is close up nature and food, and possibly some portraits occasionally, but not too often. The second type of lens i am considering is a macro lens of some kind. I really do not want to spend too much, under 500 if possible, and would like something that does a little bit of everything with a nice bokeh. The current lenses i have are just basic kit lenses, a 18-55 and a 55-200. Thanks so much :)


sareena November 28, 2013 at 1:09 pm

Wow your tips are amazingly detailed and helpful.
I have a Nikon J1 camera. Which lens should I use for blur backgrounds?


Sean December 4, 2013 at 4:59 pm

Hi Amanda,

I’d like to start off by saying this is a great article and I will definitely be sharing it.

Apart of my blogs new projects is to interview unique people. I plan on recording the interviews with my Canon Rebel t3i. I have a standard lens (18-55) and have been advised I should look into something else.

We plan on interviewing indoors (a quiet room with lots of light). I am on a budget and prior was interested in getting something like a 70-200mm as it would serve all the practical needs (professional/personal) in the future, but I am told a 50mm would be better for the videography project as it’s a wide shot?

Please advise.


Chantel December 5, 2013 at 5:32 pm

Wow, this information was fabulous. I just purchased my first DSLR camera and I can honestly say before reading this, I didn’t have a clue about lenses and aperture. The explanations and examples you gave are terrific. I plan on taking a photography class in 2014 and I am taking this info with me to the class! Thanks for your post.


Gail February 28, 2014 at 4:49 pm

Thanks so much Amanda! I’ve read so much and couldn’t make sense of it, much clearer now. My question is, I will be shooting kitchens for a cabinet maker to put on his web site. What/how is the best way to shoot toward a window and get the real wood color and grain? I would like to get a low cost wide angle lens if you have suggestions for that also. Thanks Gail


Mikelle April 17, 2014 at 5:51 pm

Ok so where do you get all your lens hoods? Or what brand do you like the best?


Amanda April 20, 2014 at 2:34 pm

Hi Mikelle! They either come with the lens or I buy them at the same time where ever I buy the lens — Amazon, BH Photo, etc. Hope this helps!

Aiden May 3, 2014 at 9:50 pm

Dear Amanda,

I have recently been looking into buying a Canon Rebel Eos T3i. I am in to more of taking videos, and many people have recommended a Sigma 30mm 1.4 lens. Is that good for videos? And can you recommend a better one if there is? I want a clear video but with a light blur in the back round. Tell me what you think! And thanks for the help!

P.S: I usually take videos for Youtube.


Sonea May 15, 2014 at 11:47 am

Hi! I’ve been browsing lenses online and in photography books for couple of years and I just couldn’t get my head to remember these numbers. Now I feel like I finally understand what they mean and I can finally go find the lens I really need. Awesome, you’re super great! Thank you :D


Natalia May 16, 2014 at 1:24 am

Thank you so much for this!
It is very helpful and nicely described, just exactly what I was looking for.

Greetings from Switzerland!


Leesha August 20, 2014 at 8:17 pm

Hi, I truly enjoyed this article. I still have so much to learn. I have checked out these lenses and they are just too expensive for me. I am mainly going to my camera to take pictures of grandchildren and then later for nature. I have been told to make sure the lens I get has IS, DO and USM. Although I actually only know what the IS stands for. I am looking to spend hopefully under $200. I am not picky if it is used or new as long as I don’t get took. I want to take pictures at games and first days of school and things like that. I like to take close ups when I can’t be close up. Can you suggest a lens within my price range? Is it true on a zoom lens that it takes longer for the picture to actually take? I have a Canon Rebel T3I camera and just have the lens that came with the camera. Thank you


Arun September 9, 2014 at 4:21 pm

What kind of lens would you recommend for my Canon EOS 4oD for shooting indoor school events?


Robin September 11, 2014 at 8:55 am

I love your photography related posts, I learn so much. You have a way of explaining things so they just make sense. I’m relatively new to photography and have a T3i with 2 kit lenses 18-55 and 75-300). I’ve also purchased a 55mm which I love. I’m now looking to get an everyday lens that I can take as my only lens to travel with. I’ve found a Tamron AF 18-250mm f/3.5-6.3 Di-II LD and wondering your thoughts on it. Do you think this is a good lens for my needs? Please do more photography posts.


Shirl September 14, 2014 at 12:15 am

Y’all are really great. I can’t believe how many photography tips and tricks you share – they’re awesome! You and your cute dogs remind me of our cute house rabbits. I love you guys. We’re from New Jersey, but my husband’s family is also from ‘ Bama! XO Thank you for sharing so much!


Crystal Kniffen October 3, 2014 at 9:05 pm

I am planning for an African Safari right now and I am wondering, If you could only take 1 lens what would it be? What else would you take? Keeping in mind, of course, that I will have a limited amount of space.

Thank you!


heather November 17, 2014 at 1:42 pm

Great post! Question – what kind if lens do you suggest for group shots? I love my 50 mm and the bokeh I get with it, but I feel like I need to sacrifice the bokeh for clarity on all the people. Is there a way to get the best of both worlds?


PB November 19, 2014 at 8:33 pm

Great post Amanda. I see you’ve recommended the Tamron 17-50 f/2.8 in your post, how do you think it fares against the Sigma variant?

Your valued opinion would be much appreciated. BTW, I am a Nikon user.



Amanda November 24, 2014 at 4:33 pm

I’ve never used a Sigma lens, but I was very happy with the Tamron I had on my Canon. Hope this helps! :)

Hollie December 1, 2014 at 2:11 pm


Great post, thanks for the helpful information. I was wondering if you could shine some light on the canon 24-70mm F4L lens..I am able to purchase on sale for $799.00 CDN which is about $600.00 off the regular price. Do you have any experience with this lens? In the past I’ve been using a 50mm for all my food photography (which I won’t have access to going forward) but I find that I can’t get close enough up. I really love the blurred background ability on the 50mm though. I’m hoping the 24-70mm lens will be a bit more versatile (I would like to have a good lens to take pictures of my kids as well) I was looking at the 100mm as well but I was worried it would only serve for extreme close up food.
What would you recommend as the number one lens for food photography from your experience? My lens budget is limited at this time so I can only purchase one lens. Thanks so much for your help!


Daniel January 6, 2015 at 9:42 pm


I have three Kids doing different sports, Like Cycling, Swimming and Soccer and I would like to keep those moments for life I’m trying to buy a Canon T5i but I’m not sure what deal to pick, meaning what lens will be better for long distance and indoors with low light and do not want to choose the wrong one, can you please give some advice

Thank you


Casey January 30, 2015 at 2:38 pm


I have a Canon Rebel T1i. I’d love to get the Canon EF 70-200mm f/4L USM Telephoto Zoom Lens but it’s a little too expensive for me at the moment. I am wanting to be able to take some good clear pics of my 6 year old when she plays soccer. I was looking at the Canon EF 75-300mm f/4-5.6 III USM Telephoto Zoom Lens. Would this lens be a good alternative to the 70-200mm lens? I only want to spend about $100-200 if possible. Thank you for this article! Any advice would be greatly appreciated!



vaughan Fernandes February 8, 2015 at 9:58 pm

Hey, can you tell me are the EF lenses compatible to a Canon rebel.? As am on a low budget. What would you suggest me with please email me.


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