Macro musings: answering all your macro queries

Mead Norton answers readers’ questions on what is involved with macro photography

What is macro?
Macro photography is defined as shooting extreme close-ups, where the size of usually small subjects is photographed to seem greater than life-size. Subject matter can be quite varied, but macro is primarily used to photograph insects, plants, and various other small details found in nature.

How should objects be lit for macro photography?
The best way to light macro subjects is with even, flat light, without deep shadows, and using a high-contrast background to help the fine details show up. So, using a dark background if the subject is light in colour, or a light background if the subject is dark in colour. A lot of photographers use a ring flash to help them light their subjects, since usually the camera gets quite close and can cast a shadow over all or part of the subject.

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What’s the closest a macro can get?
The right question to ask is less about how close you can get, it’s more about asking how big you need to have the subject enlarged. Macro lenses, just like standard lenses, vary depending on their focal length when it comes to the minimum focusing distance. But the magnification that is possible with a macro lens can vary quite a bit. To be a true macro lens, it needs to be able to focus and reproduce the subject as life-size (e.g. 1:1). Some macro lenses can reproduce objects five times their actual size (5:1).

What makes something a macro image? Is it just that you zoom in very close?
A macro image is not just an image that is zoomed in, it is an image that shows the subject of the image as being life-size.

What do the ratios on macro lenses mean (like 1:1, 1:2)?
The ratios on macro lenses refer to the magnification that the different lenses are capable of capturing. Half life-size magnification is 1:2, 1:1 is life-size magnification, and 1:5 is five times life-size magnification. Generally speaking, the shorter the lens the less magnification is possible. So, most macro lenses that are around 50mm have a magnification rating of 1:2, and the longer lenses (160–200mm) usually have 1:1 or greater magnification ratings.

Do I need a dedicated macro lens for my DSLR to take macro images?
If you don’t want to invest in a macro lens, you can still take macro images, but you will need to invest in various accessories to attach to your current lenses. These accessories can be useful, but they will never be able to be as clear and sharp as a dedicated macro lens. The easiest way to use a standard lens as a macro lens is to add close-up filters, which come in various strengths. You can also get extension tubes and bellows that go between your camera and lens, which alters the focal distance of your lens.

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How does the focal length of a macro lens affect the kind of photos you can take? Is it better to go with a prime or a zoom?
To determine what focal-length macro lens you want to buy, you need to first consider what you will mainly be using it for. The shorter the focal length, the closer you have to be to your subject to get the shot. For example, a 50mm macro lens is great for shooting electronics, or doing flat art copy where the subject is still and controllable. Most insect macro photographers usually choose to go with the longest lens they can find, so that they are less likely to disturb their subjects, and also don’t have to worry so much about casting a shadow from the camera, tripod, or themselves across the image. There are only a few zoom macro lenses available, and they tend to be towards the cheap end of the spectrum. Just like standard lenses, prime lenses are sharper, and since macro photography is all about capturing the small details, sharpness is key.

I like to take macro shots of animals and bugs, but find getting close enough without scaring them off is hard. Any tips?
The best way to ensure that you can shoot insects and other small animals is to get a longer-focal-length macro lens. The longer the lens, the further away you can be and still get those beautiful detailed shots.

I find getting in very close for a macro shot restricts the light a lot, how do pros deal with this?
The pros either use a ring flash to ensure that the subject is evenly lit, or in some cases they bring the whole thing into a studio and use remote lights to light the scene and studio backgrounds, to ensure that they have total control over the background.

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I find exposing correctly for macro shots to be difficult with such a shallow depth of field. Is it best to let the camera automatically expose, or do you have advice for nailing manual exposure?
I generally find, no matter what I am shooting, that it is always best to shoot in manual exposure. That way you have total control over how the image is exposed. Tips to remember include that all light meters are set to record what is called 18-per-cent grey. So there are two ways to ensure that you get the right exposure regardless of the lighting conditions. One is to carry an 18-per-cent grey card in your camera bag, and put it next to what you want to shoot — this is what photographers who used to shoot film used to ensure that they nailed the exposure correctly when they couldn’t chimp their shots.

The other way is to remember that green grass, the darkest part of the blue sky, and most European (white) skin are all basically 18-per-cent grey, so you can point your camera at any of those things, and as long as the light hitting the grass, or the back of your hand, is the same as the light hitting your subject, then the image will be correctly exposed. If you are using the sky, as long as the subject is in full sun, then the exposure will be spot on. Also this works best if you set the metering mode on your camera to spot meter, or if it does not have a spot meter setting be sure that the grey card, or substitute, fills the frame.

I like the idea of shooting abstract macro images, but I’m never sure what’s going to make an interesting/strong image. Are there any compositional rules specifically for macro?
There aren’t really any different rules specifically for macro photography when it comes to composition. Just keep in mind that with macro photography you are basically dealing with lines and contrast, so using things like leading lines, diagonals, and complementary colours all help to make strong images. If you really want to do abstract macro shots, a good place to start is to look at architectural photographers, because they have to use strong lines and contrast to make good images.

What should I be looking for in a tripod for macro photography?
A really handy feature to look for when looking at tripods, and thinking about shooting macro images, is to look for tripods that allow for the centre column to be used horizontally. After all, if you are doing macro photography a lot of the time, you will be looking straight down on the subjects and don’t want to see tripod legs at the bottom of the image. 

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I find it really hard to get focus right when I’m in close to a subject — the autofocus goes crazy. Is manual focus the only fix for this (it’s tough with moving subjects)?
The best way to get images sharp when shooting subjects is to try and prefocus your camera, use the depth-of-field preview to see if enough of the area is in focus, and wait for the subject to move to that point that you have prefocused the shot. Also setting your autofocus to a single focus point can help to prevent the camera from jumping from one focus point to another.

I know ‘focus stacking’ is a popular editing technique for macro images, how is that done?
Focus stacking, for those who don’t know, is the combining of multiple images shot at different focus distances so that the entire image is in focus. It is very similar to shooting an HDR image, but instead of compensating for dynamic range, you are compensating for depth of field. You can focus stack an image two ways. One is to keep the camera locked in place and change the focus point, and the other way involves physically moving the lens closer to the subject and keeping the focus point the same. Once you have a series of images you then merge them together in Photoshop, or another software program. 

Here are a few tips to remember when focus stacking an image:

  1. Always be sure to keep all the camera settings the same — shutter speed, aperture, ISO, etc.
  2. Ensure that the light does not change between exposures.
  3. If there is movement between images, then the process will not work.

This article originally appeared in the June–July 2015 issue of D-Photo (Issue No. 66). You can pick up a print or a digital copy of the magazine below:

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Mead Norton

Mead Norton is a commercial photographer originally from Texas, now living in Rotorua. An outdoors and adventure specialist, Mead has shot for a range of clients, events, and publications, both locally and internationally, as well as hosted various workshops on the craft.

His portfolio comprises a wide array of subjects, including winter sports, biking, running, triathlon, water sports, travel, and portraiture — a repertoire that has won him a long list of happy clients, as well various industry awards.

As well as contributing valuable technical articles to D-Photo over the years, Mead regularly publishes helpful posts on his blog.