Tips on How to Choose Your Next Lens for Photography

Tips on How to Choose Your Next Lens for Photography

One of the questions that crops up often on photography forums, sites, and even in photography conversations over a pint is "which lens should I buy next?" It is said with such sincerity and met with so many recommendations that are, in the end, mostly meaningless. It even rears its ugly head in the form of "What is the best lens for 'X' photography?", as though somehow, another person's answer will guide the asker to greatness.

In order to truly ask the right questions about the lenses we need or desire, we must understand what makes them different from each other. There are optical differences between lenses that cause different focal lengths to render scenes differently. For the sake of simplicity, all focal lengths in this article will be talked about in 35mm "full frame" terms.

Field of View

Let's first consider two lenses, one 24mm and one 85mm. These two lenses differ in their field of view quite significantly. The 24mm "sees" approximately 84 degrees, whereas the 85mm sees around 29 degrees. In practical terms, this means a 24mm will "include" more of a scene or background than an 85mm. When photographing a person, for example, and keeping them the same size in the frame, a 24mm lens will see a lot more of the background.

Perspective Distortion

Again, looking at the two lenses of 24mm and 85mm, we can see a significant difference in perspective distortion. With the 24mm lens, objects, or parts of objects closer to the lens appear larger than those farther away. The distance between objects can also be greatly exaggerated with wider lenses. This might be useful for showing how large and powerful a boxer's fists are in a portrait, or for creating the "converging lines" effect with railway tracks. Tilting wide lenses up or down will also have a much greater effect on the vertical lines in your image than with a longer lens.

Converging lines here are caused by using a 16-35mm lens at 19mm.

With the 85mm, almost none of this effect will be seen. Longer lenses will do the opposite, drawing farther objects "closer". This is great for rendering far away backgrounds effectively closer to your subject in a portrait, for example.

This is the same scene on the Han River in Seoul. The left image was shot on a 35mm lens, and the right image on an 85mm lens. Note how close the buildings appear in the right image.

Depth of Field

Although depth of field is a function of many variables, including aperture (larger aperture means less depth of field) and focus distance (closer focus distance means less depth of field), it is also greatly influenced by focal length. An 85mm lens, for example, has an inherently narrower depth of field than a 24mm lens. If you're looking to send your backgrounds into buttery oblivion, a longer lens may be the ticket. An 85mm lens at f/2.8 will have a shallower depth of field than a 24mm lens at f/2.8, given the same focus distance.

Both shot at f/2.8. Although the focus distance changed slightly, we are still able to see the extreme difference in depth of field between the 35mm (left) and 85mm (right).

My Lens May Not Work for You

The initial question is not a bad one in and of itself, but it's the wrong question to ask most of the time, and asked of the wrong people. The way I use a 24mm lens may differ from the way you do. You might be asking for a recommendation for a portrait lens and I would certainly recommend my 24mm for portraits, whereas a beauty photographer will most likely tell you to stay away from a 24mm lens and go for something closer to 85mm. This lies in our differing intentions when photographing portraits. I like to be physically close to my subjects and am first and foremost looking for a genuine moment, not necessarily a flattering portrait. Thus, a more beneficial question would be: "what lens would achieve the aesthetic I want?"

Your Way of Seeing Is What's Important

So, when looking for a new piece of equipment, or even simply taking a lens out of your bag to shoot with, consider the aesthetic before anything else. Consider what you want to achieve. After all, we are visual artists. We need to understand which tools to use so that we can create the image we want. This is what will make great images, not the lens that another photographer thinks we should have.

Dylan Goldby's picture

Dylan Goldby is an Aussie photographer living and working in South Korea. He shoots a mix of families, especially the adoptive community, and pre-weddings. His passions include travel, good food and drink, and time away from all things electronic.

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i agree 100%. it's just as bad with cameras. as if someone would make a huge purchase because i said it was nice. sadly i think some people do. i may not like a 85m but some can't live without it. i can't do without my 70-200 2.8 but i see them for sale every day. i would never trade my Nikon D3 but for many it's too big and heavy. i don't need a billion mp in my cameras so i'm not caught up in that. i need a high frame rate so the D3 works for me. i don't really care that it's FX, my D3x is not and i still crank that. the main reason i went to the D3 was the better low light (a lot better) than the D2x was. i also do not shoot video so i don't care about that function either.
basically what works for me is me. if you will buy something that someone online says you need is just foolish and you should first do your homework and see what you actually need as opposed to want. many lens fit into that. i don't own a 24mm lens but i do own a 85mm but it's old and manual focus but works for me. i don't need the best out there.

Great examples Dylan. I think that if someone asks what lens they should get next, chances are they shouldn't get any lens at all. When you need a new lens, you know exactly what it is you need. (Of course, things like asking whether the Nikon 105mm is better than the Tamron 90mm are a different story.)

you should do the same article about cameras +) cheers!

The two photos in the 'Depth of Field" section had to have been shot at rather disparate distances to make the subject the same height when the first was shot at 35mm and the second was shot at 85mm!

@michael buehrle - You can say you don't care that the D3 is FX, but the reason it has superior low light performance is a direct result of the increased light gathering capability of the larger sensor.

Well, when i was about to buy the Canon EF 135 f/2 USM L lens, the preachers came to me. They told me that I should have bought the 85 1.8 instead and save money for a better camera. Back in the day I was shooting with the Canon EOS 500D/T1i.
Well, i've bought the EF 135, because i loved the way it displayed people's faces and still i never regret buying it. Now with the EOS 6D, yup, it became even better :)

So yeah, when you pick up a lens, make sure it pleases you. My next lens will be the Sigma 85 1.4. And then...i'll think about wide angle lenses, as they do not please me.