Nikon BC-7

[rodeo_joe1]

I've just found out what an Air-Gap Flash is......:eek:

Probably safer just to wait for a bolt of lightning to coincide with your picture!

[mike_halliwell]

a bolt of lightning

I gather that the rise/fall time of LEDs is pretty quick...they work in nS.

 

I wonder if there's a high-speed LED flash-light possible?

[FPapp]

I used to like those clever ones with 4 in 1 flash bulbs in a cube that rotated 90 deg to allow the next one to fire...:cool:

"Kodak instamettic flash"...:);)

 

I saw some hot shoe to FlashCube adapters on Ebay, I was thinking about picking one up to play around with! ;)

[rodeo_joe1]

I wonder if there's a high-speed LED flash-light possible

Anecdote: I bought a little 4 colour (RGB + W) 'parcan' disco light. It's programmable with 255 brightness levels for each colour, and the brightness is pulse-width modulated. The minimum pulse-width turned out to be around 1us, and even at that short interval the rise and fall times looked pretty square on a 10ns/division storage oscilloscope. The detector was just a simple photodiode working into 50 ohms; so the diode capacitance most likely limited the measured rise/fall times.

 

However - big however - the energy output of the LEDs at that short a timescale is tiny. Nay miniscule... nay nanoscule, picoscule... and whatever the next 3rd decade of tininess is called.

 

In short, you need a very, very, very bright LED and supply it with loads of current to generate a useful amount of light at micro-second pulse widths.

I saw some hot shoe to FlashCube adapters on Ebay

I bet you could advertise hobnail-boot to high-heeled-winklepicker converters on eBay and someone would buy them.:cool:

Edited August 3, 2020 by rodeo_joe|1

[mike_halliwell]

In short, you need a very, very, very bright LED and supply it with loads of current to generate a useful amount of light at micro-second pulse widths

Sounds good to me!

 

Dumping a BIG capacitor into a 100W LED.. hummm

 

I don't know enough to know about capacitor dump-time...:confused: