Amateur’s Food Photography – Choosing a Focal Length

by Jenn on September 14, 2012

in Photography

Cherries

What’s the best lens for food photography?

I often get this question, and I’m always hesitant to give anyone a concrete answer.  I usually reply with something vague that probably is not what the person wanted to hear, such as “it depends”, simply because going into all the considerations of choosing lenses could take up far more time than one might initially expect.  Heck I’m just an amateur, I’m sure I don’t even know all the ins and outs of lens choices myself.

I’m not going to get into a heavy gear discussion on which brands, models, are better yada yada yada.  Everyone has their favorites for various emotional and technical reasons, and I’ll leave it at that.

What I am going to talk about, however, are just a couple things to consider when choosing a lens length.  On a point & shoot camera, there is no lens length to choose, other than pushing the zoom button in or out to alter our field of view. On an SLR, different lenses come in different lengths – longer lengths offer a more zoomed in view, and shorter lengths offer a more zoomed out view.

Let’s start with 50 mm.  A 50 mm lens is just that – 50mm long.  This is a length that lets the camera pretty much see what the eye sees – there is no “zoomed in” or “zoomed out” when you look through the camera, and because of that it is often suggested as a great length for beginners. What you see with your eye is what the camera sees too.    That and most major brands make an extremely affordable 50mm lens, and I like to use its popular nickname, the “thrifty fifty”.

So if we are using a 50mm lens, how do we zoom in or zoom out to get more or less of the scene in our image? We “zoom with our feet” – by moving closer or farther from the subject we can adjust how much of the scene ends up in the frame.

But what if you can’t move forwards or backwards so much?  Then we have to use other focal lengths in order to change what fits into our field of vision.  Shorter lens lengths are called “wide” lenses because they do just that – they let the camera see a wider range of view.  And longer lenses do the opposite, giving a narrower range of view.  Zoom lenses allow you to set a variety of different focal lengths all in the same lens.  When we “zoom in”, we are using a longer focal length and when we “zoom out” we are using a shorter focal length.

I know what you’re thinking, “Yeah yeah, I know how to push the zoom button on my camera or turn my lens on my SLR to zoom in/out, how does this help with food photography?”

Because the focal length – the length of the lens – affects more than just how much of the image you can see.

focal lengths

In the series of images above, I kept the camera setup the same  – and merely changed the focal length on my zoom lens (yes, oftentimes my setup really is this crude):

Pullback

If you look carefully at the series above, you will notice that more is going on than the cherries simply getting larger/smaller.  You can see much more of the surroundings in the zoomed out image at 24mm (which you probably expected) and a much narrower field of view in the zoomed in image at 70mm.  But something else is going on as well – if you look at each image carefully, you will see that as we change the focal length, the appearance of distance between objects changes as well.

Distortion and Compression

 Camera Focal Length from Wikimedia Commons – watch the perspective of the cube change as the gif steps from wide angle to normal focal lengths.

For focal lengths shorter than 50mm (often called “wide” lenses, especially, say 24mm and shorter), as we go to shorter and shorter lengths and thus become more “zoomed out”, we see more in our field of view, but perspective distortion comes into play. Perspective distortion is caused by relative differences in distances from the lens.  The distances between objects in the frame become exaggerated, often due to the fact that with a wide angle lens, one ends up getting much closer to the food for the subject to fill an adequate part of the frame.  It also means that closer objects look bigger, and farther objects look much smaller.  Going back to my image above comparing different focal lengths – see how at 24mm the table appears to be stretched out and the peaches look so far away from the cherries? That’s perspective distortion.

For focal lengths longer than 50mm (getting into a range called “telephoto” lenses), as we go to longer and longer lengths and thus become more “zoomed in”, we see less in our field of view, but the background’s appearance changes.  Notice how much larger and closer the peaches look when I go from 50mm to 105mm:

compression

This is called compression – as we go to longer lenses, we back away from the subject to get the same image in the frame.  We change the relative distances between the subject and the background, and the result is that the background becomes compressed, appearing closer and larger relative to the subject.

In food photography I think it’s important to be aware of these things, because we are often photographing our subjects at rather close distances.  I often find myself putting the camera as close as I can that will still allow it to focus on the subject.  Thus, since our distance to the main subject tends to be on the shorter side, relative distances from the foreground to the background make a big difference and we can easily see the perspective effects of the length of lens that we choose.

With my style of photography, I like to choose the longest lens I can get away with.  I like the compression of the background that a longer length brings, and I think it lends itself nicely to rich creamy bokeh (bokeh = that blurry background).  But a longer lens means you need to have the room to be able to stand farther away from the subject.

If you don’t have a DSLR you may be wondering how this is at all useful to you – but if your point & shoot camera has optical zoom, then zooming in/out will also affect the perspective and how objects appear in relation to each other.  Depending on how much optical zoom capability your point & shoot has, the effect may be more or less dramatic, but it will still be there.

Other useful links:

Want to read more in my Amateur’s Food Photography Series? Check out my previous posts:
Look at photos with a critical eye (and making fun of one of my early ones!)
Food photography is about celebrating light
Take your time and find your “zen place”
Angles of Light
Pay Attention to Props
The Histogram
It’s Not the Camera, It’s the Lighting
Exploring New Directions
Plate to Page Workshop Summary
Building an Image
Shades of Gray
White Bean and Ricotta Salad
Apple & Caramel Dumplings
Prosciutto Corn Muffins and White Balance
Creamy Cauliflower Soup and effect of gobos
Bruschetta with Arugula Pesto – Styling challenges
3 Reasons Why I Love my Tripod

 And as always you can find links to several great food photography tutorials I have found across the web on my resources page – Food Photography Tutorials.