How do I achieve the abstract effect for fireworks that is sometimes referred to as the hirobamboo method? Specifically what types of lenses would work best for this, do I start in focus or out, shutter speed range?
Source:
How do I achieve the abstract effect for fireworks that is sometimes referred to as the hirobamboo method? Specifically what types of lenses would work best for this, do I start in focus or out, shutter speed range?
Source:
It looks like the photographer has changed the aperture during the exposure, using a manual lens. The lens starts wide open when the firework first explodes and is then quickly stopped down.
I guess it just takes a lot of practice snapping with one hand and twisting the aperture ring with the other. A lens that offers a continually variable aperture (like many motion picture lenses) would be best as there are no click stops that will create gaps in the aperture trails.
You can get this effect by changing focus during the exposure. This can be done with any lens though you it will help to physically limit the focus ring so it stops automatically at the point of true focus (which will be a close to the infinity focus mark). I guess this can be done by attaching a couple of zip ties round the lens.
Edit: it's definitely changing focus, not aperture in the examples given. Not only is this method easier to do as it doesn't require a manual aperture ring, the proof is in the brightness of the trails. Changing aperture would give a dot of constant brightness as ways happening is more and more of the disk of light is being blocked as the iris closes. When you change focus the light disk gets more concentrated and thus brighter.
Fireworks require a long exposure. In this case, the photographer shifted focus while the camera was capturing the fireworks. For this reason, the shape has points from the time the image was in focus it widens as the image was pulled out of focus.
It is easiest to start with the image in focus and then defocus as time passes, rather than the other way around. I am sure this takes tons of shoots to get a few good ones because you cannot see what you are doing unless your camera has a Live-Bulb mode. In this case you need to enable focusing in bulb mode or use a lens with a mechanical focus-ring.
Given the requirement, this is impossible to achieve with any camera and lens combination that does not allow focus to be changed manually during exposure. AFAIK, this excludes all fixed-lens cameras at this time.
I asked this question apparently too soon, because only a day later the photographer himself answered this question on the Colossal blog here: Unusual Long Exposure Firework Photographs by David Johnson
The way that he achieved this is outlined in an email correspondence found in the above link and quoted here:
The technique I used was a simple refocus during the long exposure. Each shot was about a second long, sometimes two. I’d start out of focus, and when I heard the explosion I would quickly refocus, so the little stems on these deep sea creature lookalikes would grow into a fine point. The shapes are quite bizarre, some of them I was pleasantly surprised with.
This is done by changing the focus during exposure. Set the camera to take a shot of around 1 second. Start out of focus, and refocus quickly near the end of the firework burst.