viewing spray patterns

$10 mini strobe light:

You can get strobes free from a photofinisher. They'll have a box of torn-apart disposable cameras for recycling. The flashes in those aren't very powerful (120 uF, 300V, about 5 joules) but might be perfect for close-range work as you describe.

Do you have an old electronic ("strobe") flash for a camera? If you do, setting it for it's lowest power setting will also give you the shortest flash. If it's a small flash unit, that will be very short and it may stop action. Older flash units and smaller flash units give shorter flashes than larger and newer ones.

-- Ed Huntress

I found blue light the most dramatic for testing spray patterns.

Make sure the light does not shine at the camera, and if possible have a dark background.

I was testing the spray pattern of a nozzle for a homemade burner, and spraying oil/alcohol mixtures as well as water. White light just didn't work as well, for whatever reason.

I have no facts or evidence that this would help - but - I'd try a polarizing filter as well.

It doesn't really make any sense, but there was a big difference in how the pictures came out. It was with a plain canon digital camera, and a maglite with a blue LED bulb replacement. That worked better than all sorts of other lighting arrangements, including strobes, and the typical

100 and 200 watt bulbs in the aluminum reflector clamp on things.

I was using an impinger type nozzle from Bete, and except for lots of dripping, it matched what the catalog claimed it would do.

They really aren't joking about don't use teflon tape. It will have pieces tear off, and it will clogs things fast.

Our photog set up a nifty device at work many years ago, Probably not what you need for this task, but worth mentioning. He mounted a 35mm camera on a plate with a motor driven disk in front of the lens. The disk was about 6 inches in diameter and had several radial slots about 1/8" wide. He could run the motor at variable speeds. As an example, he set the camera for perhaps 1/2 second, and spun the disc such that 10 slots passed the lens in that half second.

We were actually filming a bomb releasing from a aircraft model in a wind tunnel. He tripped the shutter as a bomb was released, and each frame of the film had the bomb photographed 10 discreet times to form a stop action sequence.

that sounds like these monsters:

"Ed Huntress" wrote

Can you please explain to me what the use of only one flash of a strobe would be?

Steve

Nope, I'm familiar with rotating mirror high speed cameras, we also had them for ultra high speed work. This was a fairly simple to make device. I can't remember if it was shop-built, but it would be feasible to make it yourself. And it had multiple images of the action on *each* frame, very nice.

[ ... ]

I've seen devices with *two* rotating discs. The faster one had multiple slots around its diameter. The slower one (geared to the faster) had only one, so you got fewer exposures per second, but still just as short.

Enjoy, DoN.

Or a strobe tach Ebay Item number: 260194170839 turn the knob and vary the flash rate.

Thank You, Randy

Remove 333 from email address to reply.

"Strobe" is the misnomer applied to electronic camera flashes, based on the fact that they use a xenon flash tube like a strobe light. Many people know them by that name. One flash is...one flash.

-- Ed Huntress

[ ... ]

Not all are so limited. The Nikon SB-800 can put out a string of dimmer flashes ending with a somewhat brighter one just before the shutter closes to give multiple images slightly underexposed ending with one fully exposed.

But more interesting is my old General Radio Strobotac, which can either be tuned to the speed of a rotating or cycling object (or slightly slower or faster to allow you to view it in slow motion), or can be triggered by the object (with an optional delay circuit to allow viewing an event somewhat downstream in time from the triggering event.

Enjoy, DoN.

On all of the old film cameras I owned in my life, there was a buildup time between shots. There was no multiple flashes like today's that correct some things caused by flash, like red eye. IIRC, all of mine were Braun, a spendy item at the time.

Steve