INCREASE LIGHT by SQUEEZING LEDs With a FRESNEL

Some time back someone asked  me,

I just want to find some way to make an RGB bulb spot light as tight a beam as possible for my Disco ball ?

Here is a BIG 10mm Bulb LED being Squeezed into a tight beam by lens to just a spot 10 feet away.

Step 1: What Is a Fresnel Lens

Maybe first .....  what is a lens ?

• A neat device to bend light
• Usually Round Glass or Plastic
• Increasingly useful through our racial history
• Big glass Lenses are Heavy

But ... Fresnel Lenses are thin, lite and use only the light bending parts of a lens see the pictures.

No need to be alarmed... In the hand pic #4,  I have all four fingers.  The Lens edge does not see my little finger.

Fresnel plastic lenses are flat and light enough to snail mail a whole 10½ inch square lens.

Step 2: RGB MR16 LED

MR16 Lamps in discreet restaurants and bars are a favorite localized lighting.

Here is an RGB LED array masquerading as an MR16  providing a multitude of color effects.

Step 3: Holding Plastic Fresnel Lens

Using forcep clamps _{made in Pakistan} to hold the 10½" Sq Fresnel by two corners.

Several colors of the LED MR16 Lamp compressed to a small circle 8 feet distant.

And No...... the Fresnel is obviously not color corrected.

Step 4: SINGLE LED ACTION

NO  FRESNEL  NEEDED

Aim a single 10mm LED powered from a Cadillac Light Thief  at
the glass refracting globe fourteen feet away.

The LED is a 15º dispersion angle and covers a ten inch globe
without using a Fresnel lens to focus a tighter beam.

Step 5: REFLECTING GLOBE

See the Globe in the light of a Single LED.
Just a few pictures with-out using a Fresnel aiming lens.
I used this glass globe in place of a Disco-Ball.


FINALLY

Placing a DISCO - BALL in the center of a 30x30 foot dance floor
Illuminated by assorted 10mm narrow dispersion LEDs will
give you 900 square feet of dancing lights to enjoy :-)

Comments

[amandaghassaei]

great idea! do you have a permanent solution for mounting the fresnel lens? or will you just stick to the single LED solution?

[chintans]

use any aixiz laser housing lense or modify the casing to fit the led in it.

[iceng]

Thanks,
If making several, I would find a shorter focus, Fresnel about 6" diameter
and a 30° RGB LED near the focal point ( Adjustable ) all in a 6" tube
which could be cardboard ( almost no Heat to worry about ) make it
ceiling hung and a cell phone vibrator to add jitter to the beam aimed on
to a rotating Disco ball.

A

[MDheliMech]

Do you think this would work with an IR emitter. I was thinking of using IR for my shooting gallery project. The problem is the IR emitter beam is very wide allowing it to be detected by the collector when not pointed at the collector.

[iceng]

The IR shooting game Iv taken apart used a low power IR laser in a TO72 or TO39 case.

A laser coherent beam is ideal for your application.

Otherwise you can get narrow 15° IR LEDs and a plain plano convex 1/2" dia lens will do.

A

[MDheliMech]

I feel bad hijacking your instructable with an unrelated question. However as much as I want to use a laser I have been concerned about safety. Is an IR laser dangerous to the eyes like a visible laser, red for example? It is likely my kids will be playing with the shooting gallery too, under my supervision of course.