High-Speed LED Pulsing Experiments

This page is currently being populated with past experiment data.  All future experiments will be added shortly after their completion.

The plans for Edgerton are available for anyone to build their own high-speed flash.  I designed the flash by building a prototype and doing lots of testing.  Until now, I haven’t kept an updated log of all the experiments performed on the LED’s.  Maybe some people would like to see all the details behind the designing and prototyping of the flash.  Others may be interested in designing their own high-speed LED flash.

The complete experiment logs can be found at github.com.

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Edgerton, A High-Speed LED Flash #DIY

2019-07-25 – The list price of the well-designed Vela One has recently dropped.  I originally quoted it at about $1,750 CAD but unfortunately don’t have any proof.  As of today, the Vela website indicates it is exactly $1,526.70 CAD. The archive.org website shows that the price has indeed fluctuated over time.

2019-08-01 – A big THANK YOU to NQTRONIX who has kindly gifted me an active light probe of his own design.  The probe will be used with an oscilloscope to measure the flash duration, trigger response time, light output -v- current, and other helpful things.  I will update this post with the data once testing commences.  NQTRONIX put a TON of time into designing, testing, and optomizing his probe.  Please consider checking out his instructable page and leaving him a like or comment!

2020-07-01 – The ‘Mark 2‘ high-speed flash is complete!  The plans are available to build your own, or contact me if you’re interested in purchasing a strobe.  I’m focusing my development on the new E2-A and promoting it as a replacement for the original Edgerton strobe. 

  • If you’ve put money and effort into building the original Edgerton flash, please continue using it as it has the same performance as the newer E2-A.
  • If you are considering building a strobe, I would encourage you to use the newer E2-A design as a more robust design.
  • If you are set on building the original Edgerton strobe in order to save a few $$, then the main control boards are available at https://www.tindie.com/products/19592/.

2020-07-03 – I’m realizing that the following notes should have been added back when I first made this post, but better late than never.  I’ve personally never experienced a catastrophic LED failure during normal use, but at the same time I feel potential users should be made aware.

IMPORTANT NOTE #1: This strobe pushes the capabilities of the LED’s.  Complete failure of the LED’s is possible.  That means the expensive components can be accidentally destroyed and require replacing.  I’ve taken many precautions in the design to prevent this, but please consider building a strobe at your own risk.

IMPORTANT NOTE #2: The LED’s are not as powerful as a Xenon flashtube, and they do not turn on as long as a typical camera strobe.  Expect to crank up the ISO by several stops (4 or more) in order to capture usable images.


EDGERTON

Named in honour of the legendary Papa Flash.

Some time ago I designed and built a ballistic chronograph and used it to take some high-speed photos of bullets striking glass. The results were great, but the photos were somewhat limited by the standard ‘speedlight’ flashes that I used – there was always some motion blur. Edgerton is a ‘High-Speed Flash’ which uses LED’s to make one-microsecond flashes to freeze motion.

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Camera Timelapse Rig (IREnE) #DIY

PREAMBLE:

Note: As of August 26, 2019, the most incredible home-built camera rig award goes tomingul’s 8-Degree-Of-Freedom robot! It takes up an entire room and can be given gcode to perform some amazing camera effects.  My rig isn’t as cool, but much more mobile and simpler to build.

Camera sliders are fun tools to use for making dynamic timelapse videos, and they come with some cool features.  This is a clever little gadget that moves like a camera slider but folds much smaller.  Eggtimers are also commonly used to make a similar effect.  Some high-end gear can slide and rotate the camera at the same time for a particularly cool effect.  But how do you guild one that one that could go up to 11?

IREnE (Inverted Radial, Extension, Eggtimer) is not only named for the clever woman (nee Adler) who outsmarted Sherlock Holmes , but also the clever functions it can perform.  The ‘Inverted Radial’ is the slider’s defining feature which doesn’t seem to be possible on any consumer camera sliders.  It moves the camera in a circle around the foreground subject in a way that keeps the subject in view while the background view is constantly changing.  Here are some examples:

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Tracker V2.1

Andromeda Galaxy by td0g

Preamble:

Most DIY astro-tracking mounts can be described as either low-quality barn-door mounts (with questionable door hinges used as pivots) or high-cost and effort equatorial mounts (typically equipped with complex drive systems).  The original Tracker V2 was designed to be an attempt to combine low-cost and high-quality elements in a single mount.  The basic design could be described as a hybrid barn-door/equatorial style mount.

That said, Tracker V2 was tested using a 250mm lens on a cropped-sensor camera and did not produce sharp OR consistent images!  Further examination at the shop revealed that the 10-32 nut and threaded rod caused the arm to advance erratically.  There was no way to eliminate or even mitigate the issue, so a bit of an overhaul was in order.  Enter: Tracker V2.1!

NOTE: While the V2.1 modification corrected the drive issue and made the device useful for unguided DSO astrophotography, it suffered from usability issues which made setup and targeting very difficult.  Improvements were made for the V2.2 upgrade, which concludes this project.  I currently building a V3, which will be another screw & arm-driven equatorial.  It will have 2-axis auto-guiding among other improvements over the V2.x design (which has admittedly been a product of evolution rather than design and planning).  

Andromeda Galaxy by td0g

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Tracker V1 – Proof Of Concept

NOTE: See the more recent Tracker V2.1 post for a working star-tracking mount.

I’ve recently developed a healthy interest in astrophotography.  A very useful tool for photographing the great beyond is an astrotracker.  It counters the rotation of the earth (360 degrees per day) and allows for long exposure times without creating star trails.  Here’s my POC build- it’s as cheap as borscht and worked great for very light loads.  However, it failed to properly support my camera setup- a 5Dc with Tokina 16-28, total mass of over 1.8 kg (without the battery grip).  As such, it is to be dismantled and a better version is in the works (waiting on eBay China parts).  That said – If you have an SL1 with an EF-S lens (less than 1kg total mass), this may do the trick!

  • MDF
  • Screws, 1/4 nuts, 1/4 ready-rod, hot glue
  • Linear actuator from DVD-burner
  • eBay China L298N dual H-bridge – $4
  • eBay China mini breadboard – $1
  • Power resistors – $10
  • ATTiny85 microcontroller (and programmer)
  • Various tidbits here and there

The linear actuator operated on 5v, which meant that our 12v supply needed to be tamed with a couple resistors (biggest cost of the whole project).  I used a 11×17 sheet of paper, folded into a tube for the 8xAAA battery holder and a spring to apply pressure to the battery contacts.  A cheap battery holder will be a welcome update for the MK2.

As a note for future projects: the linear actuator was excellent for light-duty projects.  Do not de-solder the power supply ribbon, instead simply cut it.  The ribbon provides support to the feeble leads coming out of the motor (I ruined one motor by treating the leads harshly).  The microcontroller was programmed to provide power for a brief duration (500ms) during each step.  This greatly reduced heat build-up in the actuator, and likely greatly improved the actuator’s life.  Finding a 5v H-bridge would be a nice improvement over the 12v L298N.