Published 10th September 2012
Macro photography can be seen as simply turning small things into their larger than life versions in finished photographs through close-up shots. That is basically how we describe it today. On the other hand, its classical definition states that it is one in which the size of the subject on the negative is greater than its size in reality. In this type, we will be dealing with concepts like the reproduction ratio, which is the ratio of the subject size on the film plane or image sensor plane to the actual subject size. A macro lens will usually be used, which is classically defined as lens capable of reproduction ratios greater than 1:1. Now, also included in that category are lenses with large reproduction ratios, not necessarily exceeding 1:1.
Our definitions are not limited by technical photography and film-based processes, wherein we take a look at the image on the negative or image sensor. The finished print or on-screen image can be used to determine a photo’s macro status. For example, in a 6” x 4” (15cm x 10cm) print that was produced using a 135-format film or sensor, a life-size result will be possible just by using a lens with a 1:4 reproduction ratio.
Depth of field problems with macro photography
One unique challenge in doing macro photography is having to deal with depth-of-field problems. Basically, the more light you pour onto the subject, the smaller the aperture that can be used on the lens, and the greater the depth-of-field will be. Also, the central point of focus here is not at the centre of the range of the depth of field. This section will also be discussed in articles on various forms of macro photography, wherein the same principles will be applied.
Depth-of-field limitations can be used when taking portraits in order to throw the background out of focus. In macro photography, it is particularly critical. Halving the lens aperture will result into a doubling of the depth-of-field. And when you are shooting a subject just a few inches deep from the plane of the camera, part of the image may still be out of focus.
Macro photography is typically used for creating images of small objects like jewellery, toys, flowers, insects, and confectionary.
Varying the light intensity can produce significant effects. LED lights will usually give you more control of your working environment. With depth-of-field, you can also play with variations like in instances when you do not want to have the entire subject in focus. Sometimes, you will want to highlight the main element of the subject and put the less important details out of focus.
In macro photography, there are a few simple rules you can live by. First, the smaller and closer the subject is to the camera plane, the shorter is the total distance from the front to the back of the in-focus area in real terms. Also, greater light intensity will allow you to close the shutter aperture to increase the depth-of-field. It is also important to remember that the distance from the central point of focus to the front of the in-focus range is half the distance to the back of the in-focus range.
And lastly, if you really want to achieve a great effect, you cannot forget this one simple rule. Be creative and let your imagination run wild! Sure, macro photography may come with various limitations, but what endeavour does not come with obstacles? It’s all up to you how you will use the limitations to materialise that great effect you have in mind.