Flaming red flower

[jgomez65]

Another flower macro shot using extention tubes

[chintex]

Beautiful picture. Which flower is this?

[hugy789]

Lovely shot, ould you tell us some more about the extension tubes.

[Flesheater]

cool shot....a nd crazy flower

[lowbone]

Extension tubes usually come in a set of three varying lengths. They can be used individually or together. A set of tubes usually has a combined length of about 68mm.
The purpose of the tubes is to reduce the minimum focusing distance of the lens so if you have a lens that has a minimum focusing distance of say five feet, you can use tubes to shorten this distance. If you have a 50mm macro lens and use a set of tubes you will have a 2X magnification lens instead of a 1X. If you get tubes it is helpful to get a set that links to your metering. Kenko makes a set like that that is very poular with macro shooters.
All is not utopia with tubes though. Focusing becomes difficult and is usually accomplished by moving the camera back and forth. Infinity focus is lost so you probably don't want to leave them on your camera all the time. There is also a light loss. That varies depending on whether you use one, two, or the whole set. They are valuable at times though. If you get them don't waste money on Nikon or Canon tubes as one of their tubes will cost more then an entire set of Kenko tubes. There is no glass in tubes. They are strictly a method of getting the back element of the lens farther away from the sensor.

[lowbone]

The flower looks hot on the ends of the pistils. There is no detail there. a minus 1/3 or 2/3 exposure compensation would probably fix that.