Visualizing coil detection area

[Ed in SoDak]

I guess I've been thinking about coils lately!

It came to me that I could use an LED to get a time-exposure image of the shape of a coil's detection field.

My digital camera allows long time-exposures, so I set it for 20 or 30 seconds at f8 (manual focus and exposure) in a darkened room and placed it on a counter aimed at the detector coil. The detector was set for all metal and I tried to scribe the edge of where the LED plus battery was picked up by the detector. That wasn't much metal, so I added a small pocket knife.

These first attempts are pretty crude, as my hand was always bobbing about while I tried to stay on the outside edge of detection, but I think with a little refinement, one could use the technique to help visualize the actual shape of a coil's extended detection field.

What do you all think? It's pretty easy to duplicate, with plenty of room for improvement on my idea. Anybody else wanna post their attempts?

-Ed

 

[jimjimmyjames]

That is amazing. I set this up this morning(4:30 am) and started playing around with it. Now, I just found out my USB ports are dead and I can't load the images from my camera. I now have an $1100 DSLR and I can't load the pics on my PC to do anything with them. Talk about irony.

 

[Ed in SoDak]

Wierd! On my old camera, the port broke inside the camera, so I had to pull the memory card and use a reader. On the Mac, the keyboard and mouse plug into USB. I don't know how a Windows machine is set up. Maybe try another port? Doe your camera require a driver be installed? Bad cable? Boy, you got me, but good luck.

How did your coil pattern tests turn out?

-Ed

 

[jimjimmyjames]

The patern tests came out a little too bright, I am going to try again in a darker room this evening. As far as my USB ports go, they are confirmed dead. Even my Ipod will not load now, on any port. I am asuming my motherboard is to blame and it's time to update to the I7 Pentium chip anyways. I love Macs too, but my need to run Autocad and a few other PC only design programs leaves me stuck with Windows hell forever....

 

[Ed in SoDak]

Not that it matters as there's more to it than just the OS, but the newer Macs can run Windoze as well. Mine's a 2001 iMac model, still pluggin' along with that and an older OS.

Maybe on your digital you can just lower the camera's ISO setting or use a smaller f-stop. My tests were made in my old darkroom, so all I had to do was shut the door and douse the lights. I used the LED to find the camera shutter. I need a better way to plot the pattern. Thinking a momentary switch; turn the light on when it gets detected, turn back off, move and repeat to build a pattern of dots instead of a continuous swirl of light. I'm just holding a bare LED onto a "coin" battery, plus palming the pocket knife for added metal, so it's kinda difficult to manipulate well.

Green or white might workbetter than the red LED.

Good luck with your "confuser" problem!
-Ed

 

[jimjimmyjames]

You read my mind for using a switched light. I have played with 'light painting' in the dark before and had great results. Here are my idea to make a cool photo:

1: Camera on tripod with long or R/C shutter release

2: Detector held in place with gun vice(or similar)

3. Switched LED on string or wire.

As long as the detecotr/Vise doesn't move, you could even shoot an image of the detector in regualre light and photoshop a really neat image(is it considered HDR?).

Just ideas,
Jimmy