One of my favourite lenses for macro food photography is the Nikkor 105mm macro. I remember back when I first started in food photography. I was looking to take my work to the next level and discovered that a lot of the shots I wanted to take required this type of narrow macro.
From the get-go, I loved working with this lens. But sadly, I hear from so many other photographers that they don’t share my love for this lens.
The most common thing I hear is that they aren’t able to get in focus shots. After talking to many other photographers about their focus issues with macros, it became clear there was a lack of understanding about the plane of focus.
Many aren’t aware of what it is and how it affects macro photography. So I’d love to change that with this post.
Let’s chat plane of focus for macro food photography. Read on friends!
What is The Plane of Focus
The plane of focus is a two-dimensional ‘plane’ in front of the camera at the point of focus. This plane will give you the sharpest focus at a particular depth of field.
Just re-read that for a sec. Let it sink in.
This is an imaginary plane and lies parallel to the camera sensor, (unless using a something like a tilt-shift lens. It doesn’t follow these rules). When you change the position or angle of your camera, the plane of focus remains relative to the sensor.
That means the plane of focus changes as the angle changes, (but it always remains parallel to the sensor).
The plane of focus is relevant for not just a macro lens, but photography in general. So whether you are using a macro lens or not, for tack sharp focus, the plane of focus is something you want to familiarise yourself with.
Here it is visually. At the point in which you focus on, that is where the plane of focus will be.
Now the Depth of Field, will be around the plane of focus as you can see above.
If you missed Lauren Caris’s post on everything you need to know about macros, click to get savvy then read on!
Do You Really Know Depth of Field?
It’s reasonable to assume that you know what depth of field is if you’re reading this post. But there are two points I want to make that even I didn’t fully understand until a few years into my journey.
Firstly, let’s recap depth of field.
Depth of field is the distance between the nearest and further objects that are in acceptably sharp focus.Wiki
The depth of field is determined by the focal length of your lens, the distance to your subject and your aperture.
Here we have the same image, at the same distance, but just different apertures. One large (small number f/3.5) and one small (large number f/8). You can see that we have different depth of field (DoF) as we have different amounts of focus in both images.
But what you may not have known about with depth of field is that the smaller the distance from your subject, the thinner the depth of field. I won’t get into the ‘why’ behind this, but let’s just say it’s physics.
To recap this point as it’s important:
The smaller the distance to your subject, the thinner your DoF is at any given aperture.Matt Korinek
If you’re 2m (6ft) away from your subject shooting at f/4 the depth of field will be 8.25cm (3.2″) wide. But half that, to say 1m (3ft) away from your subject at f/4, your DoF is 1.95cm (0.76″).
That’s 4 times thinner at the closer distance.
So with a macro, f/8 will be super shallow if you are really close to your subject.
Which brings me to the next point.
We See Thinner DoF With Macro Lenses Due to Smaller Distances
Now that we know we can get closer to our subject, (which is only possible with a macro due to the minimum focusing distance of these lenses), we can understand why macro lenses feel shallower.
Using a DoF calculator, I’ve calculated the relative depth of field (how ‘thin’ or ‘thick’ DoF is) at:
- The minimum focusing distance of the Nikkor 105mm micro
- The distance I like to typically shoot with my Nikkor 105mm micro
- The minimum focusing distance of a non-macro at 100mm
Let’s look a this visually.
Even if you are finding it hard to understand this concept, just look at the bars above in ‘visually compared’. See how incredibly ‘thin’ the DoF is at minimum focus distance where the yellow arrow is pointing.
This is why so many photographers feel their macro lenses aren’t performing in terms of focus. Because they are shooting on the same apertures they would at larger distances.
In the little Mocha Cake on the right, even at f/8, look at how shallow or ‘thin’ this DoF is. Here I am at about minimum focus distance for this lens. So I have a thin amount of DoF here. Hence a smaller aperture (larger number like f/8).
So to offset this, when shooting with our macro lenses we need to change our aperture. For my macro lens, I typically start shooting at an aperture of f/5.6-f/8.
Again, this will depend on the distance, but for those close macro shots, I start here.
Now, you’re ready to dive into the plane of focus. Let’s go!
Related: Check out this post on what makes a macro lens different.
How The Plane of Focus Works
When we select a point to focus on in our frame, that becomes the plane in which we find things in focus. Now remember that this plane is parallel to the camera’s sensor. So as we change our camera’s angle, we change this plane.
Anything that is in front of this plane will be out of focus. Similarly, anything beyond this plane will also be out of focus.
(And here’s the cool thing, the degree to which it is out of focus depends on your aperture and relative distance).
Both of these shots are taken at a similar distance and with the same settings.
But in the image on the right, more of our subjects are in focus. (I purposefully shot at the largest aperture I could to get as much blur to visually see this working).
This is due to the plane of focus, and where I focused in the frame. Both times I focused on the pink macaron in the bowl.
The Plane of Focus With Visual Examples
Now that you’ve seen the results, let’s look at the plane of focus for each shot. (Remembering that our plane of focus is parallel to the camera’s sensor at the point of focus.)
The camera is at the same distance, with the same settings. Only the angle is changed, (and hence the plane of focus which is the pink line).
You can see from the behind the scenes shots that our plane of focus in this second shot, the 75-degree angle ‘touches’ the top of more subjects.
This is what allows this second angle to give more focus.
How To Get More of Your Frame in Focus.
Depending on your concept and subject, you may want more of the scene in focus. When using a macro lens, there are two things you need to consider.
- The aperture that you are shooting at and
- The plane of focus due to the angle/position of your camera/sensor
Sometimes just changing the aperture won’t be enough to bring what you want into focus as we’ve seen. (Because the DoF is thinner at smaller distances).
So you might need to change your angle in combination with your aperture.
As we are relatively closer to our subject with a macro lens, you can still achieve a shallow depth of field at smaller apertures.
The first thing you will want to do is increase the depth of field by shooting at a smaller aperture (larger number!). If that doesn’t give you the focus you want, then you will also want to change your angle for a different plane of focus.
Recipe by Tessa Huff ~ Icing On The Cake
Recap of Main Points
Now I know this can feel like a complex subject, so if you feel a little like ‘wha?’, here are the main takeaways.
- The plane of focus is a two-dimensional ‘plane’ in front of the camera at the point of focus.
- It’s parallel to the camera’s sensor and will give you the sharpest focus at a particular DoF.
- With our macro lens, we can get closer to our subjects so the effects of DoF give us shallower results at each relative aperture.
- The closer you are, (the less distance), the thinner DoF is. You’ll see the effects of focus/blur more.
- To get more in focus with your macro lens, change your aperture to smaller aperture (larger number) and/or –
- Change the angle and hence the plane of focus so it’s ‘touching’ more subjects at the same level that you want in focus.
Want to know a little bit more about what makes a macro lens different? Check out Lauren Caris’ post she did in collaboration with me.