Most enquiries I get through Flickr relate to macro shooting, from the kit to get to the best techniques and keen shooters not getting the results they expected. Today I'm posting a quick introduction to get things going...I will get more specific in further posts.
While there are many interpretations of what "Macro" is I understand "true macro" to start at 1:1, that is the object you are shooting appears at life size on the camera sensor. For example, if you are shooting a wasp 20mm long, it will be that size on your sensor, so if you have a digital SLR with crop sensor (23.7mm for Nikon) that beast will be a frame-filler. Non-dedicated lenses, which can include primes or zooms, are not capable of "true macro" so it is probably more accurate to call it "close-up" photography.
The manufacturers do their best to confuse us, with many calling dedicated lenses "Macro", Nikon calling them "Micro" and some describing lenses that can focus closer than average as macro, when they are not actually capable of 1:1 reproduction.
There are further tricks available to get more magnification..enter close-up lenses, reversing rings and extension tubes...all designed to enable a standard lens to focus closer and so increase magnification.
Basically speaking, a true macro lens is capable of focusing at a very close distance to offer maximum magnification of the subject. Most macro lenses fall within the 50mm to 200mm focal length range. They all offer 1:1 magnification but the distance at which they do so will increase with the focal length.
You do need to consider focal length before you choose your lens as shorter lenses will not be the best for shooting bugs etc as the close working distance will scare them away. Pick too long a lens and you may find it hard to handle or prone to camera shake.
While small animals demand a dedicated lens, larger animals I have photographed, such as dragonflies, butterflies and tarantula spiders, can be shot at well under macro magnifications, if you want to frame the whole animal.
As for technique...like anything worth doing it does take some patience. You will have a razor thin depth of field to work with, so nailing the focus point correctly is a must. In the true macro range you will rarely have enough natural light to shoot at a suitable ISO sensitivity to preserve detail, so you will need to master use of flash. Once you are doing fine with these, start to consider composition more carefully.
One thing I would add is that macro is very addictive....yes it takes a while to master, but it opens up a whole new world and can be done in a spare half hour in the back garden...fantastic!
As for cost, you can get set up for relatively low cost if you already have a good flashgun and even cheaper if you don't yet wish to get a dedicated lens and intend to use your existing telezooms, or something like a 50mm prime with extension tubes. The dedicated lenses do cost, but this varies and a typical bug lens like a 105mm is £300-£500.
