Archive for the ‘Show-n-Tell’ Category

Open source PID controller

Posted by 3ricj on 5 January 2012

My friend Brett Beauregard has been working on this sweet open source PID controller.. and he's finally published information online about it here.

A PID (proportional–integral–derivative) controller is a device which use hardware feedback with an algorithm; this allows the operator to maintain a target value (temp). Cruise control in car is the classic example: Set it at 60mph, and it will increase the accelerator until you hit 60. There are all sorts of things which can go wrong with closed-loop control systems - - overshoot, ringing, bias, etc. As this device is all open source, as it will make debugging these devices much easier.

It's currently on "presale" for $85. I think this is a sweet deal. If you want to make your own Sous-vide cooker, this is the ticket. Go buy one, as I want to make sure this type of hardware is available to the masses. I'm excited to get mine.

Posted in: Show-n-Tell  

This video shows the upper deck of the viaduct being demolished by massive jackhammers, while a brave construction worker sprays water to keep the dust down. It looks like we should expect an alien to come jumping out of this video at any moment.

I heard the viaduct was going to be closed for a week or so, but I wasn't expecting them to demolish it. Oh well, it's not like I was using that highway anyway?

Filmed in 1080p on a canon 5d mk II, 200mm, f2.8

This was my first try at doing a long exposure on a digital camera of the night sky. An external timer was used to keep the shutter open for 45 minutes.

Even after touch up post processing, the image is very, very noisy. The noise floor on most sensors has quite a bit to do with how warm they get. Folks go to extremes to get their sensors cold, the most typical solution is to use a TEC/Peltier junction. One issue with these chillers is that they only push heat to the other side of the plate - - you still need to get it out of the system somehow; this is typically done with large heatsinks and fans.

I found a company which will modify your stock DSLR to have a chiller, but it's a very expensive prospect, on the order of 3 grand. I think I may try modifying a cheap point and shoot camera first to see what sort of results I can get... if I can find one which will let me take long exposures. For now, I'm going to make sure I get my camera to take a black reference first (doh*), but this effectively doubles the time it takes to do a shot, as the exposure time has to be the same for the black reference.

Anyway, here's my first attempt at this:


This was shot on a 5d mark II, using a 24mm f1.4 prime lens. I'm happy with the result, but I crave less noise.


Posted in: Show-n-Tell  

Time lapse of Seattle..

Posted by 3ricj on 15 July 2011

I've been playing around with time lapse photography... Here's my first attempt at something. which came out pretty cool:

Posted in: Show-n-Tell  Tags:

Slow Motion Match Strike

Posted by lindes on 15 July 2011

With thanks again to Intellectual Ventures, for use of their Phantom V12, here's a bit of slow-motion video of a match striking. Playback speed varied to keep it to 30 seconds for a project I'm doing; the original was close to 7 1/2 minutes. Please excuse the clunky music. If anyone out there is a composer and wants to help me out, I'd love to hear from you -- click through to my flickr stream and contact me from there. :) Anyway, here's the video:

High-speed (near-)macro is neat, eh?


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