In this light painting tutorial I am going to show you how you can take long exposure photographs of water drops on a psychedelic colorful reflective CD surface with a Mini Maglite flashlight.
I'm using a water dropper, a M2A016 Mini Maglite Flashlight, a regular CD, a Nikon D300s DSLR, a Manfrotto 055XPROB Tripod, and some color gels. I also used an ND8 Filter so I could use an aperture of F11. The gels and ND8 filter are optional.
I was using these settings:
Shutter Speed: 5-60 seconds
ISO: 100 (or "Low 1.0")
White Balance: "Incandescent" for correct color, or "Auto" for warmer colors
Take the water dropper and place a bunch of droplets on the CD after you have put it on a table of your choice. The table I was using was a laundry basket with a thin black blanket over the top. Fancy!
Next, put your DSLR on a tripod and place it right up next to the CD. I was using manual mode with manual focus most of the time (but not always, a lot of DSLR cameras have an AF Assist Lamp in the front of the camera that helps focus in the dark, in situations just like this!)
In order to get my aperture to f11, I was using a simple ND8 filter in front of my lens. This isn't necessary, I just wanted my photos really sharp, and f11 is the sharpest spot on my lens. You can go down to f22 or smaller and skip using the filter if you want. Just use the highest f number you can and the lowest ISO number possible. This will limit the amount of light being exposed to the camera sensor, which is what you want in this situation. Maglites are bright!
Try making different patterns around the CD with the Maglite flashlight. A really cool one to do is to place the light level with the CD next to the table. This creates a perfect circular reflection in the circular water drops on the circular CD! Really cool.
Try pointing the light diagonally down on the CD, and just try different directions and distances away from the CD. You are bound to get a cool shot.
In order to help me be sure that I get the psychedelic rainbow colors on the reflective CD surface, I Temporarily widened the aperture on my lens to f3.5 and then went into Live-View Mode. This makes it easy to see exactly what the camera sees, so you know what direction to aim the light to get colorful rainbow effect. After you see the rainbow effect appear on the CD in your viewfinder or in Live-View mode, get out of live view mode, go back to smaller aperture you were using before, and then take yo' picture.
Photoelasticity Birefringence is a visual phenomenon that occurs when placing transparent plastic between polarizing material. The effect shows the stress contained in the plastic.
In order to take pictures like this, you will need to place a hard transparent plastic object between two polarizers. Make sure your object is backlit as well. Fortunately, LCD computer monitors are backlit AND have a linear polarizing material in front of the backlight, so this takes care of everything. If you go this route, all you need to do is find some cool looking plastic and stick a polarizer filter on your lens and you are set to go. If you don't want to use a laptop computer screen or just want to to get rid of the ugly RGB pixels, use a light table with polarizing paper on top of it instead.
You'll also want a polarizing filter to place on your lens. This can be circular or linear, it doesn't matter. Things that work well are cheap transparent plastic cups, forks, spoons, and knifes. Prisms, plastic wrap, and cheap packaging material work good as well. Things that unfortunately don't work are water, glass, and anything that isn't a transparent plastic (crystals might be the only exception, although this is unconfirmed). Water can sometimes look okay-looking, but not nearly as cool as plastic.
Here is a how-to tutorial on long exposure photography with sparklers. I also show you how to make perfectly symmetrical psychedelic patterns just by using your DSLR, Adobe Photoshop, and sparks from your fireworks in part II of the tutorial. Make sure to pick up your fireworks the day AFTER Independence Day because they are usually on sale.