Digital Macro Photography, An Overview

In this article we explore some aspects of macro photography with digital cameras. Macro is an excellent photography area that can really make good use of the strengths of digital cameras. This is the first of a series of articles on macro techniques and subjects.

0.5 second, f16 and 100ISO, Sigma 70mm Macro on Canon 400D

Macro photography is a great and interesting area of photography. Technically covering the area of close-up photography where an object is reproduced on the sensor at a size of at least 1:1, these days it is also commonly used to refer to all close-up photography. Because of the close distance (relatively if not in actuality) from the subject to the lens, rangefinder or compact cameras were not ideal for it because the viewfinder would not reflect exactly what the lens is seeing. However, with the advent of digital, and thus the possibility of a live preview of exactly what the lens is seeing on the large LCD on the back of the camera, compact cameras now become quite convenient for macro work.

0.5 seconds, f5 and 100ISO, Sigma 70mm Macro on Canon 400D

Another positive for many compact cameras is the amazing degree of close focusing ability many possess. Some digitals can focus so close that they can actually achieve focus on an object touching the front element of the lens. Of course, an issue with compact cameras is the small sensor size, which causes noise issues. This is partly compensated for by another positive that derives from the small sensor size, lens focal length. Because of the tiny sensor size, compacts need very short focal length lenses. In a given situation, shorter focal length lenses give you greater depth of field in practice (see the separate article on depth of field for the correct definition and more explanation). This is why compact digitals have much greater depth of field in actual use than a 35mm full frame camera or even a digital SLR.

1.5 seconds at f5.6 and 100ISO, Sigma 70mm Macro on Canon 400D

Digital SLRs are dependent on the lens you fit to them for their close-focusing ability. Basically a macro lens has to allow for more lens extension to focus more closely. You can also achieve this lens extension by using extension tubes or bellows. A macro lens is designed to maintain good optical quality as a greater lens extension is used. Many zoom lenses come with macro capability, which can be extremely useful. However, maximum image quality is usually achieved with a dedicated, single focal length lens. Macro lenses come in focal lengths from 50mm (sometimes less) up to around 200mm, with the most common in the 50-100mm range. These will have greater effective focal lengths on most digital SLRs. A longer focal length gives you more working distance from the camera to the subject for a given framing. This working distance can help in close quarters, with some types of subjects that may be scared away or are dangerous and in getting light onto the subject (too close and the lens can cast shadows).

1/6 second, f5.6 and 100ISO, Canon 100mm Macro on Canon 400D

I have a Canon 100mm f2.8 macro lens, which I love. But I have also been working recently with a Sigma 70mm f2.8 macro lens, which is fantastic. Both can get to a 1:1 magnification without extension tubes. Both are very sharp lenses, both autofocus on the Canon very well, even at macro distances.

My macro rig includes several Canon cameras, a macro lens, extension tubes and a homemade light

The great joy of macro photography is that it is a form of photography that you can do in most situations. In the field you can do macro photography on flowers, plants, insects, rocks, sand, rusting metal, you name it, you can macro shoot it, so long as you can get close enough. If the weather is too cold or too unsettled or dangerous for photography, set some things up indoors and happily shoot away while the gale blows outside. Whatever your passion in photography you can find something similar that you can shoot, from lovely florals to crystal landscapes, insect portraits to fungal forests. There are people who spend their entire photographic career shooting macros only, and never run out of great subject matter. I’ve recently been exploring crystal and rock macro shots and exploring the potential for crystal landscapes by combining images. This is fun and a diverting, and quite creative and is a great way to spend time when housebound.

Here is a piece of amber from my collection (1.5 seconds, f22 and 100ISO, Sigma 70mm Macro on Canon 400D)

Macro lets me get up close and personal with the insects trapped in the amber

So what exactly do you need for macro photography? A digital compact camera will work fine. One with a tilting LCD screen can be a great help when working in certain situations, but is certainly not essential. Likewise a good tripod is a help for certain types of subjects. I use a large Manfrotto model, where the center column can be removed and inserted horizontally. Whilst not the same as a macro rail, it allows me to easily move the camera forward or backward at will. A macro rail is a massive aid in accurate positioning of the camera, and is something I will add to my kit at some point. Naturally when you are working on some sort of tripod, a cable release or wireless remote is also useful. Now, of course, a tripod is not essential. You can do great macro work handheld.

The beauty of digital is immediate feedback

If you use a digital SLR, then you either need a macro-capable zoom, a true macro lens, extension tubes or a bellows, or close-up accessory lenses that screw onto the filter threads of your lens, to begin. There are various pros and cons to all of these, from price to flexibility. Many of you will already have a macro-capable zoom lens. I am a big believer in exploiting the potential of what you have before running out to purchase something else. So whatever you have, try using it. The cheapest additional purchases are extension tubes and close-up lenses. Extension tubes seem to give the best result of well corrected single focal length lenses, but they can also work well on zooms. Close-up lenses, particularly if good quality ones, are a good option on lenses which do not currently focus close enough for your purposes. I have happily used them on my Canon 100-400mm IS L series lens for a long working distance. The thing is to experiment. Close-up lenses can also be used on compact cameras.

Depth of field is an important creative control in macro photography. See the special article on depth of field
1/25 second at f2.8, 100ISO, Sigma 70mm Macro on Canon 400D

In the three images below we show how increasing depth of field has a major impact on the resulting image

Lighting is important for macro work, as you often want to work at small apertures for a greater depth of field. I’ve used everything from a torch to ‘paint with light’, an external flash gun, like the Canon EX flash units that can be wirelessly controlled, a ring flash, tungsten lights, gold and silver reflectors and my own made ‘light pipe’ unit.

Here I use my lighting rig to light the front of the object (1/6 second, f2.8, 100ISO Sigma 70mm Macro on Canon 400D)



Whereas here we have the lighting set to come through the subject. (0.7 sec, f2.8, 100ISO, Sigma 70mm Macro on Canon 400D)

Some of the accompanying photos show a lighting rig I wired up for macro work. It is a very simple rig, just two bright, white LEDs with battery packs and a switching potentiometer that both switches the LED on and off, and also can dim it somewhat. I mounted two of these into a box with wire that allows me to position the LEDs as I need. Wire is not as easy to use for this as flexible, gooseneck fittings but it is a lot cheaper. The LEDs can be positioned as needed and provide enough light for macro work of small objects. They are small enough to hide behind transparent or translucent subjects or can be positioned to the sides of the lens to light opaque subjects. To make one of these all you need are the LEDs, battery packs, a switch or switching potentiometer, wire, a box and soldering iron, which are available at any electronics shop that sells parts.

2.5 seconds, f16 and 100ISO, Sigma 70mm Macro on Canon 400D

1/2 second, f11 and 100ISO, Sigma 70mm MAcro on Canon 400D