Super Simple Snoot

A snoot is a device which prevents the spill of light and/or the light source being seen from anywhere other than the target.
Snoots are used in theatre alot (also called top hats) and are used to prevent light spill and ensure that the only light seen is that reflected off the target, not that from the lamp itself.
Snoots are very useful in the bedroom to allow one to read while not disturbing the other occupants with "light pollution".

Step 1: Measure twice cut once.

Equipment:
-Knife
-Cardboard (black and thick, flame retardant) DO NOT USE NORMAL CARDBOARD!!!
Alternatively black foil could be used which is obtainable from theatrical shops.....
-PVC tape (Flame retardant)
--Cheap halogen bedside lamp that spills way to much light

Measure the outside of the lamps head (pic 2) and ensure card is long enough.
A piece of A4 should be sufficient for most lamps.
Also measure any protrusions or knobbly bits

Comments

[SIRJAMES09]

I like this instructable, I think it's well written & easy to understand, BUT....
I just have 1 small problem with it...

I do not trust paper anywhere near a lamp for any length of time.

Speaking only for myself, I'm at the computer for hours on end(12 - 15 hours or more even)...There is just no way I would feel safe knowing that there is a piece of cardboard attached to my lamp.

That paper is the ONLY problem I have with it. other than that, I love it.

[spylock]

I agree itd bother me also.Im doing a lamp that has to be adjustable as well as have a concentrated beam,I have to take an injection once a week,and cant find a lamp like I need in stores.Im gonna use a section of 2" thin wall PVC a foot long painted black,and will use an insert plug drilled out for my fixture as well as a 2" x 1 1/2" coupling for the focused beam.Ill use a camera tripod for my base.But all and all,nice,and with the new cooler fluorescent bulbs,and the fire retardant paper,he should be fine.

[SIRJAMES09]

speaking of gasket material, there are places where you can go to the manufacturer & buy gasket material....now I'm not talking about automotive gasket material, I'm talking about the kind of gasket material that is used in space, in blast furnaces, etc.

Some of that high quality material comes as thin as 1/32 of an inch(1-2 mm) to as thick as more than 1 inch/cm. I know this because I use to work for a place that made gaskets for the space shuttle & also made pads or shoes for the brakes on a 747 airliner(as well as smaller apps too).

and much of that material had a temperature rating of like 5000 degrees Fahrenheit & up.

[SIRJAMES09]

Q:
I have seen plastic pipe that come in black....would this not work as well? Or would it too be a fire hazard?

[lycoris3]

can't you use a cup?  that sounds a lot safer then iffing about a piece of paper catching fire, flame retardant or not.

[millenniumtree]

This black cardboard looks a bit like automotive gasket material.  You can buy it from any good auto parts store in sheets.  Since it is used in/around engines, it's probably fairly flame resistant.  You'd probably want to test a bit of it first though, especially with a halogen lamp like you've got there.

[strmrnnr]

This is a similar technique used for leading lights when used in navigation. A longer tube and more powerful light is used of course. Seen from a distance if you are one or two degrees off course there may be a different color light or no light at all. If you are following the right course into a narrow channel the light is white. They are very accurate and reliable if you know how to follow them. Nice Instructable.

[cowscankill]

Can this be used on a normal lamp to let a plant grow?

[Myself]

Simple is right, I always thought there'd be baffles inside or something! I'd definitely use metal, and I bet spray paint goes through a phase when it's not wet enough to come off on your hands, but not yet dry enough to crack and crumble off, so you could probably paint your own metal then curl it up...

[dancook]

Flame retardant cardboard has to be uses, although the card/paper has an ignition point of 231 deg celcius and as a issue I would have thought the lamp head itself would never get to that temperature as the plastic would melt. Having the snoot white or foiled internally would act as light channel and cause alot of dispersion, defeating the point of the snoot. I may just put a little sign on about the fire warning.....

[Patrik]

Actually, large halogen lamps can easily reach temperatures above 500 deg Celsius. Mind you, light bulbs of similar wattage will give off roughly similar amounts of heat, regardless of whether it's a regular incandescent bulb, halogen, CFL or even LED, because the majority of the electrical power actually gets emitted as heat, not light. It's just that halogen bulbs tend to be much smaller for a specific Wattage, so they reach a much higher temperature in a smaller space.

[dancook]

Having gone on a mini mission to investigate the temperature of the casing and surround for the lamp I've found the max temp (using an IR thermometer is 85 degrees c on the small metal bits holding the glass in (see picture in notes) which is well below ignition point. The point is valid though and precautions should be looked at. In the real world snoots are thin black steel constructions...

[DonQuijote]

this cardboard tube is black on the inside.... that absorbs a hell lot of light, transforming it into heat. try painting it white on the inside..... or putting aluminum foil on the inside, carefully though, not to touch any electrical parts of your lamp (i honestly hope this advice was not worth the effort of writing it. if you don't know what you stick where, and what might happen if, then you are not supposed to void warranties....)

[Patrik]

Covering the entire inside in aluminum foil would make for a very poor snoot, because you'd get reflections going outside the area where you want to aim the light. Covering the first inch or so closest to the lamp may not be a bad idea though.

[DonQuijote]

yeah, i haven't thought about that.... well... that's how brainstorming works....

[Patrik]

This instructable could probably do with a big DO NOT USE ORDINARY CARDBOARD! sign.

Halogens are notoriously dangerous because they run so much hotter than a regular light bulb.

Halogen lamp + flammable cardboard = instant fire hazard!

[Weissensteinburg]

Also used in photography =]

[GorillazMiko]

Wow, amazing job! I never knew it was this easy, I will have to do this next time I am working on something that needs light in one spot. Thanks for showing!