Household reflectors?

Flakey

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Dec 4, 2005
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If i took stainless steel bowl, poked a hole in the bottom and put a bulb through, do you think this would throw longer than say a standard mag reflector?
 

LEDcandle

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Haha... admittedly, the thought had crossed my mind but no way, no throw, but you'll get decent flood that is more or less contained and projected "forwardish" (of sorts), although there will be light loss as the bowl material is nothing like a reflector and is not designed in anyway to collimate light forward.
 

Flakey

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Dec 4, 2005
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i would definetly mirror finish the bowl first. not that hard. and i have one that seems to have a pretty good shape. hmm it just got me thinking =)
 

mahoney

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Jan 7, 2002
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It depends on the shape of the bowl.

But it might be more productive to start with a really big reflector. Ask a local theatre if they've got any old stage lights they're going to trash. Theatres are notoriously poor, so it's a long shot. But if you had asked me 6 months ago, you could have had 10 reflectors out of 8" ellipsoidals to play with.
 

bfg9000

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The only large parabola-shaped household object I can think of is a satellite dish.
 

LEDcandle

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Alu foil just creases too easily and it won't be possible to lay it out nicely in a bowl. It doesn't reflect THAT well either... :p
 

Templar223

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Nov 30, 2005
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Champaign IL
Flakey said:
If i took stainless steel bowl, poked a hole in the bottom and put a bulb through, do you think this would throw longer than say a standard mag reflector?

I had to giggle!

Seriously though, I had a cheap 3-D yellow ray-o-vac light that was hanging and the batteries leaked big-time in the garage (I never realized how much liquid is in an alkaline battery!). Brought it indoors and washed it out and the caustic stuff had dissolved the aluminized reflector stuff off the reflector.

I needed a flood light anyway, so I:

1. Sprayed photo mount spray (basically aerosolized rubber cement) onto the reflector face.

2. Glued the shiny side of a piece of aluminum foil to the face, leaving the dull side exposed.

3. Trimmed the excess Al foil away.

4. Put the light back together and viola!

One "flood" light for working in tight spaces.

rayovac.jpg


Sometimes a fella just doesn't want 800 lumens (or even 60) of light!

John
 

nemul

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Mar 22, 2005
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Georgia
Templar223 said:
I had to giggle!

Seriously though, I had a cheap 3-D yellow ray-o-vac light that was hanging and the batteries leaked big-time in the garage (I never realized how much liquid is in an alkaline battery!). Brought it indoors and washed it out and the caustic stuff had dissolved the aluminized reflector stuff off the reflector.

I needed a flood light anyway, so I:

1. Sprayed photo mount spray (basically aerosolized rubber cement) onto the reflector face.

2. Glued the shiny side of a piece of aluminum foil to the face, leaving the dull side exposed.

3. Trimmed the excess Al foil away.

4. Put the light back together and viola!

One "flood" light for working in tight spaces.



Sometimes a fella just doesn't want 800 lumens (or even 60) of light!

John

wonder how silver leafing a reflector would work?
 
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andrewwynn

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Apr 28, 2004
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Racine, WI USA
what he said about sattelite dish. Bowl will likely be spheroid or possibly elliptical but very long shot.. I just saw a 'mythbuster' where they took an 8' sattelite dish to make a 'death ray' by putting on about 6400 1" squares of glass mirror.. that worked exceeedingly well.. and i had the immediate thought of making a mini deathray by using a direct tv type dish and maybe polishing and chrome plating.. but it could be a fun project to make a super-focused LED light.. the neat thing about the way those small dishes work is that the focus is off-center so there is no obstruction from the arm!

building a parabola is not tragically difficult.. a very simple formula for a parabola is y=nr^2.. figuring out the focus beforehand is a bit more tricky.. the 'n' is just thrown in to be able to adjust the depth 'cause r^2 is a pretty deep parabola with a very short focus.. n would typically be a very small number like 0.1 or maybe even less. You could build something out of foam blocks or balsa wood.. easy to cut to make the frame.. than put some flexible ribs.. maybe copper or brass strips to make the basic frame.. else with just a bit of excel work you could figure out the exact angle and distance to make vertical blocks of various heights to attach standard sized flat reflectors, say 2" square reflectors on a 1" post.. about 60-100 of those and you'll have a pretty killer big reflector.. could probably shine a single 3W led a mile... imagine what a mag100 would do!

-awr
 
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