Affordable alternatives to macro lenses.
For most flower photography a standard lens works fine. However, in some cases, you may want to have extra magnification to shoot small flowers or show details. Rather than buying an expensive macro lens you can also use cheap alternatives that turn a normal lens into a macro lens.
I photograph many flowers with my Canon RF-S 18–150 mm kit lens. That lens gives me ample flexibility to take the shots I like. Only in specific situations I use my longer 100–400 mm lens, in particular to get a blurrier background. My kit lens allows me to get pretty close to the flowers, but sometimes I need more magnification, for example, when shooting very small flowers, or a detail of a flower. This brings us into the realm of macro photography.
There are many specific macro lenses available with magnification factors of 1 or more. (A magnification factor of 1 means that the size of an object projected on the sensor is the same as the size of the object itself. For a full-frame sensor, this means that an object of 36mm in width fills the image completely.) If you’re truly passionate about macro photography, it is recommended to invest in a macro lens. They are often also useful as portrait lenses. But if you only occasionally want to take a macro shot, a macro lens is an expensive and unnecessary purchase. There are affordable alternatives that convert a regular kit lens into a macro lens with nearly the same quality. You can either use extension tubes or macro converters.
Extension tubes
Extension tubes are hollow rings that are placed between the camera and the lens. They ensure that the minimum focus distance is significantly reduced, which increases the magnification (sometimes up to a factor of 2). There are extension tubes of different lengths. The longer the tubes, the stronger the magnification. It is also possible to combine the tubes. The tubes do not contain glass, so the image quality is not affected, but you lose a stop of light.
The smaller the focal length of the lens, the stronger the effect of the extension tubes. A lens with a focal length between 50 mm and 100 mm is ideal. Extension tubes are very affordable (around $30). You need to purchase the correct tubes that match your camera’s lens mount. Get extension tubes that relay communication between the camera and lens, so that autofocus and aperture selection continue to work. These tubes often have ‘AF’ or ‘auto’ in their names.
Macro converters
Macro converters, also called close-up lenses, are placed on the front of the camera lens in the filter thread. Some converters are threaded while others, such as the commonly used Raynox converters, click onto the lens like a lens cap. The latter is very handy because you can then quickly place the converter when needed and remove it afterwards. Make sure that the filter size of the converter lens matches the size of the camera lens you are using.
Converter lenses come in different strengths. For example, there is the strong Raynox DCR-250 and the weaker DCR-150. The larger the focal length of the camera lens, the stronger the effect of the converter. When using a telephoto lens of 100 mm or more, it is best to get the less powerful DCR-150, while shorter lenses pair best with the DCR-250. With a zoom lens, avoid using the large focal lengths,as the magnification becomes too strong. Good macro converters are about twice as expensive as extension tubes.
It is also possible to combine extension tubes with a macro converter. This will further increase the magnification to reveal even the smallest details. Below you find an example. Realize, though, that the depth of field becomes very small, so you will need a narrow aperture. For the shot below, I used an aperture of f/22. Also, focusing on the desired spot is hard. You’d best make sure there is no wind. Use manual focus and take several shots. I will discuss these techniques in a future article on macro photography.
Why use a true macro lens?
When extension tubes and/or macro converters can produce macro shots at very little cost, why would you want to use a true macro lens? There are several disadvantages of the cheap alternatives:
- A major disadvantage of using extension tubes or macro converters is that you can no longer focus to infinity because the maximum focus distance is significantly reduced. Removing them is necessary to take shots from a greater distance. The range of distances at which you can focus becomes very small. For macro converters, the range is typically 5–15 cm. With extension tubes, it depends on the focal length of the lens.
- Extension tubes cost a stop of light or more. This is not the case for macro converters, but those will lead to slightly inferior image quality.
- Macro lenses can often use wide apertures of, for example, f/2.8. While most of the time you want a narrow aperture to get enough depth of field, sometimes a wide aperture can create interesting creative effects.
So, using a true macro lens is more convenient. It provides slightly better image quality and enables some additional creative effects.
Conclusion
Extension tubes and macro converters are a cheap way to take macro shots of flowers. I personally prefer extension tubes because they offer more flexibility, especially when used in combination with a zoom lens. For an extensive comparison between extension tubes and the Raynox macro converter on my Canon R7, see my previous article on this topic.
Please note that all shots in this article were taken using a diffused flash. When getting so close to the flower, you often block the natural light. Moreover, using a diffused flash removes harsh shadows and it allows you to use a narrower aperture to get more depth of field. We will discuss these aspects further in a future article on the use of a flash.
Mark Overmars is a dedicated nature photographer that loves to share and regularly publishes about his work. You can visit his website (in Dutch) at www.insectenfotograferen.nl.
You can download his free English eBooks on insect and butterfly photography from www.insectenfotograferen.nl/book.