Macro Lens vs Extension tubes vs Close up lens vs Tele extender/converters
For starters in macro photography, there are plenty of accessories to shoot great quality larger than life shots of small subjects. One need not to get submerged by the tsunami of terms and terminology to do that. This article looks to answer some of the accessories that a photographer starting out on macro photography could use.
Let’s look at some of the accessories that one can use to shoot macro photographs. If you are a Canon user you would not have problems understanding the term macro as Canon’s macro lenses are all termed as such. However for some peculiar reason Nikon chose to address its lenses (for shooting pictures of small objects at life-like or larger than life-like proportions) as Micro lenses. To avoid confusion, this article uses the term macro to refer to lenses designed to shoot pictures of small objects.
The best option for a budding photographer for shooting macro. The specially designed macro lenses allow a shorter focusing distance and higher magnification for creating a life-like image. A life like image is anything that has a magnification of 1:1. That means the image is projected on to the sensor at the same size as it is in real life. If one were to shoot a bee with a standard telephoto or standard zoom lens, the image will never fill the sensor.
Micro-NIKKOR 40mm f/2.8G DX (Photo: Cary and Kacey)
Macro lenses have space between the back of the lens and the sensor, which allows it to focus more closely and project a life-like image. Image magnification is the term that one may come across quite a lot in macro photography. Say an image is projected on the sensor which is 1/2 the actual size. The magnification will then be termed as 0.5x.
One of the most popular and cheaper alternative is to use an extension tube. Both Canon and Nikon makes extension tubes that allows the lens to be moved further away from the sensor and thus allow for closer focusing.
Photo: Guy Sie
They sit directly between the lens and the camera lens mount. So there are threads on either side; one to be used to screw on to the lens mount of the camera body and the other one for mounting the lens on to the front of the extension tube.
Photo: John Gateley
Extension tubes don’t increase he focal length of the lens (unlike popular believe). They simply project the image bigger than normal on to the sensor. As such they affect the image magnification aspect by increasing it in the process.
Close up lenses allow a simple and effective way to reduce the minimum focusing distance of any lens. They can be mounted on to the front of any lens using the same threads which are used for mounting filters and reduces the minimum focusing distance. The glass element in them can be compared to the same prescription glasses that are used by people with farsightedness to correct their focusing ability to a shorter distance.
Photo: Alice the Photo Ninja
These close-up lenses are very thin and their strength is referred to by the term dioptre. They are available in several dioptres. They are very cheap and can be used with normal (non-macro) lenses for shooting macro images.
These are similar in look to an extension tube but they are used for a different purpose. They are basically focal length multipliers. Both Nikon and Canon manufactures teleconverters for their lenses. They are available in 1.4x 1.7x (for Nikon) and 2x from both of them. These can extend the focal length and make a 200mm lens extend to 280mm, 340mm and 400mm depending on the teleconverter selected. However they are not suitable for using wider apertures as they effectively slow down the lens. Image blur is also a constraint as they tend to get tighter and at slower apertures often get affected by the movement of the subject. They are however magnify the image, but they don’t improve on the minimum focusing distance of the lens.
Further reading: A beginner’s guide to macro photography