There are lots and lots of ways to paint with light in photography - well, the word photography itself means painting or drawing with light, literally.
There's no limits to creativity. For this post, I choose a technique that needs some "light-stick", or something similar to a "light saber".
For those images I needed also a flashgun (with RC remote and mounted on a tripod), a second tripod for the camera (also connected to a RC remote) and a lot of patience as well as lots of trials and errors.
Basically, I needed to find a path I could walk along in the dark, starting the camera exposure of 30 seconds (first remote), do my moves towards the camera (in less than those 30 seconds), then stand still and trigger the flash before these 30 seconds were over (second remote). I think it took me some 50 tries to come up with those 2 final images. The hardest part was to focus the camera. Auto-focus won't work in these light conditions, and to focus on my endpoint requires to be behind the camera to operate as well as on front of the camera to be the object of focus - I had to make do with a stick in the ground and a torch.
There are no tricks in those shots and no composite. Just single frame long exposures!
It will be easier to have an assistant for stuff like this, or a model...
For the first image I set both light strips to blue, in the second image one strip was set to red, the other to altering colors.
The lighting device i used for this is pretty simple. It's actually my second version, a bit more advanced and more stable, but still very easy to make. The first version of it ended up as a background light for my computer desk btw.
What's needed is:
1. LED strips (ideally with USB connections and controls)
2. Power source
3. Stick (meaning something long and straight) as a body to mount LEDs and power source on
LED strips are easily available, eg in hardware stores or electronics shops. Those I used are 1 meter long, run on USB power, and have 3 buttons each to change color, modes like blinking and speed.
As a power source I used some cheap-ish USB power tanks.
As a body, I used something I found in a hardware store. Sorry, I'm lost in translation (actually I wouldn't even know the German word for it), so I try to explain the thing. Its a 2 meter long piece of transparent plastic, usually used to be cut to fit and to connect 2 pieces of carpet, say in a doorway etc.
You can use a simple board for this too, but this plastic piece had certain advantages for me:
1. Easy to cut and work with
2. It has 2 chambers to hold the LED strips - so I could use 2 strips rather than only one
This setup gives me more light, I can choose different colors on each strip or even choose different modes like one blinking and the other solid color.
The whole thing, as I built it, takes only one hour or so, depending on your tools and skill.
For my double saber, I measured the plastic piece some 30 cm longer than the actual LED part of the strips. Then I measured where the control buttons will be when I insert the strips (starting on one end with the last LED). I then dremeled holes into the plastic on my markings, so the buttons are available when the strips are fixed.
The rest of the cables goes into the empty space beyond the buttons and shows up at the far end of the body.
I used some plastic strips to jam the strips in place. Some strips will have double-sided tape to glue in place, but I prefer it this way (easier to take apart if I need a new strip).
I got 2 small USB power tanks and fixed them via Velcro tape at the cable-end of the whole thing.
So those 30 cm of "empty" plastic beyond the control buttons are now holding the USB cables and the power tanks at the very end. The part between buttons and power tanks serves as grip to hold and wield the whole thing.
Due to their position behind your hands, those power tanks also serve as some counterbalance, which makes movements more fluent in photos.
... Oh, yeah, here a quick view on my "first edition". As mentioned, it ended up as a back light behind my screens...