Category: DIY

Homemade Cathode Ray Tubes

DIY cathode ray tubes
First the Sparkmuseum post and now this. What a fantastic month for mad scientists this has been! This has got to be the coolest home brew page I have seen in years.

This guy makes cathode ray tubes from scratch! This has officially buried the needle on my clever meter. Using phosphor from common florescent tubes he coats the inside of a glass tube and evacuates the air. When an electron beam exits a small hole in the discharge tube that is mounted inside the phosphor glows. He has even added deflection coils (magnets) to create an oscilloscope! You can see some videos here, here, and here. 

His other projects include a photo cell made from salt water and copper , a rectifier made from borax, and even a Homemade Tunnel Diode and RF Oscillator. He also has built his own vacuum tubes. Talk about hardcore!

Hack A Day

Spark, Bang, and Other Good Stuff

Ghost Towel

Ghost towel

 

 

Why someone didn’t think of this sooner is beyond me. A towel that will turn you into a ghost. Brilliant! You can either buy one for $30 or grab some scissors and make your own. Perfect for kids that like to play at bath time or if your drying off in an Islamic country (apparently exposed skin drives them mad with uncontrollable lust).

[via core77] 

Ghost Towel

DIY Magnetic Filter Holder for Pinhole Cameras

Pinhole filter test

As if my exposure times were just not long enough, I’m going to start trying filters on my 120 pinhole camera. I did an initial test of the filter holder and a took a few photos to figure out the exposures. Good news is that the filter holder isn’t causing a vignette on the image but the bad news is that my exposure times are going to be REAL long. Even more so when I take in the reciprocity failure factor. With a number 003 Cokin filter the exposure compensation factor turned out to be an 8. That’s a loss of three stops. My pinhole camera has an aperture of 220 so with the filter I drop to a metered stop of f/600! If only my DoF would change too…

 

Magnetic filter holder

Here is the camera with the holder and filter in place. The lumps on the sides of the Cokin filter holder are super magnets with a healthy dose of gaffers tape. These are grabbing on to two pan washers that are held on to the camera body with, what else, gaffers.  I had to carve away some of the holder to get the cable release to fit right. It should still work on a regular camera, if I ever buy a mounting ring. The project works pretty well for being held together with tape and magnets. I think I’ll incorporate metal in to the front of the cameras so I can use magnets as mounting devices in the future.

Magnetic filter for pinhole camera

A High Dynamic How To

Apple

 

 

 

Creating high dynamic range images is become quite easy once you know how. The basic idea is that you make an image that has more tonal data between full white and full black than what you would get in a regular photo. To put it better, if your eyes had a dynamic range of two then all you could see would be black and white. More range, more data. The results are pretty impressive if you ask me. I’ve managed to create quite a few of them myself. With a little bit of practice, and a sturdy tripod, you can be making your own as soon as you find a subject.

[via netorama] 

Daily Pete » HDR Tutorial: How to create ‘High Dynamic Range’ images using Photomatix

Exergia – Ideas In Light and Energy

Kelvins Thunderstorm This page fills my head with ideas! Steam engines, electrostatic generators, bi-metallic motors… Mumm.. Well if your not the tinkering kind of person then you should be happy to know that everything at Exergia is for sale. Yep, in kit form or a finished unit. So explore the wonders of science today! Or at lest by mid noon of next week. 🙂

A bit from the site:

Sophisticated demonstration models of alternative energy technologies for universities, schools and interested individuals: Stirling Engines and steam engines, fuel cells, photovoltaic objects, toys and more! Discover extraordinary ideas in energy related devices: Educational devices inspired by old and new concepts to demonstrate the physical principles of conventional and alternative energy conversion." 

[via MAKE] 

Exergia

Remote Head-Mount Gyroscope-Controlled Camera Plane

 

Ooo, an R/C plane with a cockpit mounted micro video camera/transmitter that’s slaved to a gyro on the pilots head. Lots of discussion here. Video here, here, and here (best by far, lots of close passes with the ground).

Pretty much the idea is that the camera is sending a cockpit point of view back to the pilot where he views it on a set of head mounted goggles. To add a bit of extra zing to the equation the camera pans and tilts in response to the wearers head movements. You can see the fun that could be had with this, eh? Telepresence is amazing!

Some specs and build notes from the discussion group: (prices in Canadian I think)

My equipment is old. New equipment:
Gyro:$425
headset:$699
cam: $99
video tx/rx: around $150
antenna: 8dbi patch (optional) around $60
amateur radio license is req’d because you need to exceed 10mw of power.(it’s not hard to get and inexpensive in Canada)
and also it’s easy to plug, but not easy to get good video link without video dropout. It’s not easy to explain everything for me to someone who don’t have good electronic skill, for now it’s not for everyone.
The cam in this setup is glue on a servo and allow 45 deg of panning, the servo is plug in the rudder channel if not use or on slider etc. The servo can be modified to 180 deg easily by adding two resistor on pot. lead or buying a special circuit.

Remote Head-Mount Gyroscope-Controlled Camera Plane