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No project so I'll take some pics..

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LAN_403

Tesladownunder

Sat Dec 22 2007, 05:07AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

I am in between projects at present. Nothing is really a priority although there are hundreds of things I could start.
Thought I would take some spark pics. Well 150 of them and all of me. Narcissism central.

I used my dual ignition coil run by a MOT multiplier feeding a string of SIDAC's. This gives comfortable 3 inch sparks made brighter by a capacitor (very long ceramic string)

It was a lot harder than I thought. To get a close up of a face and sparks in one shot with a reflection in an eye means a long exposure and F stop backed off all the way to 32. Almost a pinhole camera. The virtual distance of the reflected spark is so far away that it will be really out of focus and also so much smaller and fainter due to the convexity of the eyeball. So it meant a lot of sparks to get a blue blur on the corneal reflection. Without the reflection it looks photoshopped.

I have to hold my eye open and be absolutely still for 10 seconds while loud IC sparks fire off in front of my line of vision.

Having the spark closer is helpful but you can't get a 2 inch spark closer than 2 inches to your nose. I was also a little worried about cumulative UV exposure to my eye with the many takes.

The shot with the safety glasses was to get the reflection. My normal glasses have an efficient anti reflection filter.

TDU

J. Aaron Holmes

Sat Dec 22 2007, 06:52AM

Registered Member #477 Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546

Pretty cool, TDU! I really doubt if I could hold my eye steady that long.

Now you've got to somehow work out the contact lens version of your "Dalek cage" so that TC streamers can appear to hit your eyeball, yet somehow be safely directed to ground instead. Hmmm...contact lenses are insulators, right? ...

Cheers,
Aaron, N7OE

Tesladownunder

Sat Dec 22 2007, 10:25AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

J. Aaron Holmes wrote ...

Hmmm...contact lenses are insulators, right?

Yes but glass has a dielectric constant of about 8 so a fair bit of capacitative coupling at 39kHz from my big coil. A 20ft air gap might be a bit safer.

Here's my setup. The sparks seem a lot closer when they take 45 degrees of your vision.
TDU

1198317947 10 FT36314 Hveyesinglebrightside

Derek_L

Sun Dec 23 2007, 04:49AM

Registered Member #1125 Joined: Fri Nov 16 2007, 09:13PM
Location: Edmonton, Alberta, Canada
Posts: 62

TDU infamous high voltage nostral grounding strap...
patent pending

Simon

Mon Dec 24 2007, 03:03AM

Registered Member #32 Joined: Sat Feb 04 2006, 08:58AM
Location: Australia
Posts: 549

And people will just say, "Obviously Photoshopped."

I'd be worried about the UV, too. Did your eyes ache afterwards?

Tesladownunder

Mon Dec 24 2007, 03:17AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Simon wrote ...

And people will just say, "Obviously Photoshopped."
I'd be worried about the UV, too. Did your eyes ache afterwards?

Interestingly, I had remarkably few people say that for the Red Alert pic and none for the Xmas pic. I did have very prominent "no photoshopping" disclaimers on the relevant site pages and lots of construction info. If anyone said photoshopping who didn't see the site, other people who had seen the site, would come to my defence.

I was a bit worried about UV as the number of shots increased and sparks got closer and with more prolonged exposures. The intensity is still low though compared to arc welding. I was expecting a bit of grittiness. I thought I had a bit of an eye ache, but in the end it was probably psychosomatic.
There is this big growth on my nose though.....

TDU

Logan Kennedy

Mon Dec 24 2007, 05:05AM

Registered Member #1103 Joined: Mon Nov 05 2007, 06:02PM
Location: Houston
Posts: 80

wrote ...
I was a bit worried about UV as the number of shots increased and sparks got closer and with more prolonged exposures. The intensity is still low though compared to arc welding. I was expecting a bit of grittiness. I thought I had a bit of an eye ache, but in the end it was probably psychosomatic.
There is this big growth on my nose though.....

Haha, you should take a picture of the nose growth. ;)

I would've been too worried about the UV to attempt this. Call me chicken, but my eyesight matters too much. Although I'm sure the amount of UV released is fairly low, but still, better to be safe than sorry.

Tom540

Fri Dec 28 2007, 04:48PM

Banned on 3/17/2009.
Registered Member #487 Joined: Sun Jul 09 2006, 01:22AM
Location:
Posts: 617

LOL I think that grounding wire is overkill. Would be funny if you were wearing a chain coif too.

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