Finally, I have got a proper macro lens for my DSLR. It is a Canon EF 100mm f2.8 Macro lens. After receiving the lens, the first thing to do was to use it to take some photos of water drops on CD. The result of the image is impressively amazing. I regretted that I've got a macro lens so late. The super close-up distance enlarged the size of the water drops in the images. With the 100mm arrow view angle, I could focus on the area where I would like to capture. That saved my time to do the cropping and kept the quality of the images.
Tried to do a long exposure light-painting with laser light, but not good