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View Full Version : Duct tape and the transit of Venus



jfribrg
2004-May-17, 02:34 PM
I have declared myself officially ready for the transit of Venus. A couple weeks ago I mail ordered a quantity of solar filter material. Yesterday, I drilled a 6 inch diameter hole in a piece of wood, duct taped the entire piece, then glued the solar filter material to the duct tape, and finally screwed a small frame on to support the filter on the telescope. Then a few strips of velcro to keep the filter firmly on, and it was done. I tried it out, and I now regret not doing this years ago. I never thought that sunspots would look so neat.

milli360
2004-May-17, 05:13 PM
I never thought that sunspots would look so neat.
Cool!

Although you could have been using eyepiece projection all along--a less tech method, but it can be used for groups. The projection is large enough to talk to a couple dozen people, and you can showily demonstrate the focussing of the Sun's energy by passing a tissue close in front of the eyepiece.

gmiller
2004-May-17, 07:50 PM
Or skip the tissue example and explain to them why the coatings on your secondary/eyepiece have diminished and left black spots where dust was [-X A small dedicated scope for such things is probably best, but projection doesn't give you as sharp of an image as looking through the eyepiece.

With a homemade filter, you better make ()*$#* sure it's secure and won't fall off. I've seen some made soley out of the "filter tape". They're light, so they won't fall off, and give just as good of an image as the comercial glass filter I use. Personally, when it comes to protecting my eyes from something as serious as the focused light of the Sun, I'd rather spend the $200 for a comercial filter, or just not do solar observing.

Kaptain K
2004-May-18, 09:56 AM
... and you can showily demonstrate the focussing of the Sun's energy by passing a tissue close in front of the eyepiece.
Tissue paper? :roll:
When I was in college, doing group tours, we used heavy duty construction paper (0.5mm thick)! Burned through in (much) less than a second!*

* Of course, the university scope was a 12 inch (30cm) f/15 refractor!! :o

Tobin Dax
2004-May-18, 12:53 PM
Kaptian K, that 'scope sounds familiar. Where'd you go to college at?

Charlie in Dayton
2004-May-18, 09:58 PM
So nice to meet a fellow lover of Rube Goldberg on the board... (http://www.badastronomy.com/phpBB/viewtopic.php?t=13540)

Kaptain K
2004-May-19, 11:05 AM
Kaptian K, that 'scope sounds familiar. Where'd you go to college at?
Washburn U., Topeka, Ks.

http://www.icstars.com/warner_swasey/

Russ
2004-May-20, 07:58 PM
I never thought that sunspots would look so neat.
Cool!

Although you could have been using eyepiece projection all along--a less tech method, but it can be used for groups. The projection is large enough to talk to a couple dozen people, and you can showily demonstrate the focussing of the Sun's energy by passing a tissue close in front of the eyepiece.
Although I have an aluminized glass solar filter from Thousand Oaks Optical, I have tried eye piece projection, which in my opinion really sucks. Reasons:

1) I could never get a "tight" focus.
2) I have a 10" SCT and therefore (I think) after about a minute, the paper I was projecting on would start turing black and "scortch off" my little frame.
3) Building a frame that had enough travel to make focusing other than a pain was difficult.
4) While I didn't have mirror temp problems as I was warned I would, anything that passed the point focus of the eye piece (the little white dot) would almost immediately catch fire. I accidently (and intentionally) burned several sheets of printer paper this way.

I really prefer my T.O.O. filter! :D