What equipment do you need? well like everything in this world you can spend a fortune on macro lenses, extension tubes, bellows and reversing rings etc etc...
Most modern compact camera's usually have a macro setting some have digital zoom, this can get you started so get out there and snap away.
Depth of field:
Now the tech stuff. The most important relationship in photography is Aperture and Shutter speed. Together, when correct, they produce wonderful images with correct exposure and with a little help from their best friend Light, vivid colour.
As you can see with the above images the Ringlet on the left is pretty much in focus from one wing tip to another, while the Skipper right is in focus at it's head and blurs toward the end of the abdomen.
For the image in the left I used a Shutter speed of 1/125 sec and an Aperture of f11.
The image on the right Shutter speed 1/250 Aperture f5.6.
Light also plays a factor the more light there is the higher Aperture number can be used and still have a fast enough shutter speed to stop blurring.
It is the Aperture that relates to how much of the image is in focus. The bigger the number the more of the image will be sharp. However if dialling in a large aperture causes a shutter speed to drop to around 1/60 sec or below then you will be in danger of camera blur especially if you are not using a tripod.
For a more detailed explanation of Depth of Field follow this link: http://www.cambridgeincolour.com/tutorials/depth-of-field.htm
I hope you now have a rough idea what depth of field is all about :
Basic Pointers are-
1. The bigger the aperture number the slower the shutter speed will become. So use aperture of around f8 to f11 in bright conditions to keep a shutter speed ABOVE 1/60 sec.
2 Use aperture of f5.6 if you want to blur part of the image, you should get a faster shutter speed as a matter of course.
There are other factors that can help such as ISO settings which can be boosted to get the shutter speed and aperture you require in poor light conditions. Check out this link for explanation:
I hope I have convinced you to try insect photography, it is amazing how diverse our natural surroundings are especially the insect world. Take the pictures then find out what they are you will soon get hooked. If you want to know more let me know