Handle Your Camera Like A Boss | Lesson 5 | Lens Basics

If you go on the Canon or Nikon websites and look up ‘lenses’ you will get a picture with a MILLION different lenses.  Numbers and letters, red rings, white boxes and red dots, zooms, primes, aargh!!!   What the what??  How do you know what lens you need?  Don’t panic--it’s really not that bad.  By the time you get to the end of this little tutorial you will know just about all you need to know (for now).

Let’s start with the basics.  

The first number you’ll see listed or printed on the lens is the focal length.

Focal length is a calculation of the distance from the point where light rays converge to form a sharp image of an object to the digital sensor or 35mm film at the focal plane in the camera.  So basically the distance from the lens to the sensor of the camera.   It’s not how long the lens actually is.  The focal length also tells us the “angle of view” --how much of the scene will be captured and also how magnified it will be.   The shorter the focal length, the wider the angle of view.    

If you’re at a party and you wanted a picture of the whole room, you’d use a shorter focal length lens, like a 24mm.   This would allow you to get more of the room in the shot.   If you used a longer focal length, like 100mm, you’d only get to see one corner of the room.    You know how when you look at real estate listings and the rooms look huge, but when you actually go to the house the rooms look much much smaller?   That’s a ‘wide angle’ or shorter focal length lens that was used for the picture, probably a 17 or 24mm.   

Annapolis family photography | Handle Your Camera Like a Boss | focal length


The second number to be concerned with is the aperture.  You already know what aperture is/means, but in case you need a refresher, click over here and then come back.  

One of my lenses says “50mm 1:1.4”   This means that 1) it’s a 50mm focal length, and 2) the maximum aperture that the lens will open to is f stop 1.4 (or f/1.4).  This lens will not open any larger than 1.4, but it will close all the way down to f/22 if I want it to.  

Sometimes, on a zoom lens, you will see a range of apertures like “1:2.8-4”.  This means that the maximum aperture on the lens is f/2.8.  But when you zoom the lens out to its maximum focal length, the aperture changes itself to f/4.   This is pretty common with “kit lenses” (the lenses that come with your camera when you buy it) and with lenses that have a large focal length range like 18-200mm.

Um wait, what’s a zoom lens??

That is the term given to a lens that allows the camera to change smoothly from a long shot to a close-up or vice versa by varying the focal length.   This means you can stand in one place and get a wide shot of the room and then  twist the lens ring and ‘zoom in’ to get a close up shot of your grandma.  You see lots of different focal lengths for zoom lenses.  A popular one is 24-70mm.  A common kit lens is the 17-55mm. (A kit lens is the lens that comes with your camera.  Really, really expensive pro cameras are sold most often without the lens--camera ‘body’ only.)   Another good one is the 70-200mm.

The other kind of lens you’ll hear about is a ‘prime lens’.  

This is a lens that doesn’t zoom.  What?  Why would you want that?   Prime lenses typically have larger apertures, which allows more light into the camera, which allows you to take pictures in lower light.  And you already know the larger apertures will give you that pretty blurry background (or bokeh as it’s called in the photography world).   Portrait photographers use prime lenses in their work almost exclusively.  You will only see one number on the focal length of that lens, ie: 50mm or 85mm or 100mm.  And you’ll only see one aperture listed too, ie: f/1.8 or f/2.8.  Remember, that’s the maximum opening, not the ONLY opening; they all will go higher.


So now that you know all that, you can study the different listings for the various lenses and figure out what each one does (or doesn’t) do.  Most cameras will come with a decent kit lens to get you started but as you get better and better you’ll most likely want to try out some different lenses to see what each one can do for you.  If you have a kit zoom lens and want to branch out a bit, I’d recommend a 50mm f/1.8 lens.  You might hear it called a “nifty fifty”.  I think both Canon and Nikon have versions starting at about $100.  You might not think so, but this is considered cheap.  

Unfortunately, as with most other things, the better the quality, the more expensive the lens.   One that’s been sitting on the the top of my ‘most wanted’ list is the Sigma brand “Art” 35mm f/1.4.  It’s currently priced at $899  This also is considered relatively inexpensive.  (The Canon version of the same lens is $1799.)    There are several companies who make lenses to fit different manufacturer’s camera bodies.  Sigma, Tamron and Tokina are the most popular and they make some really nice lenses.  Most of the time they’re less money than the Canon or Nikon versions and unless you’re like Super Pro Photography Guy, you’re not going to notice a big difference in the images each produces.   And if you don’t want to fork over your whole paycheck on a lens that you might not like, there are several different companies who will gladly rent you a lens (and lots of other photography equipment too).  BorrowLenses.com and Lensrentals.com are two of the more reputable ones.    They’re a great option if you need a particular lens for a shoot but don’t plan on using it very much in the future.


So there you have it!  You’re now armed with more technical camera knowledge than the average man on the street with a fancy pants DSLR.  So get out there and have some fun!