how can i concentrate of a bulb light at a point ?

I have a bulb ( pic is attached )
and for some experimental work i have to concentrate its all light at a single point. can anyone help me that how can i do that ??

Picture of how can i concentrate of a bulb light at a point ?
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-max-3 years ago

You will need a small point-source of like. Have you looked into carbon arc lamps, They are very difficult to make work efficiently and tweak, and maintain, but they may suit your purpose. They can make VERY small points of light that is very easy to focus into an almost laser-like beam.

If you insist on using a light bulb, do you need the 40W the one pictured gives off? Will you be OK with using a small xenon lamp or halogen lamp instead? the filaments are smaller, more condensed, and give off more intense light. I would have recomended an HID lamp but you sayed you need a blackbody radiation, so that may not suit your needs.

Kiteman3 years ago

If you need a bright light at a point, you'd be a lot better off using a much smaller light-source, such as a superbright LED.

m_uamir72001 (author)  Kiteman3 years ago

No, i need bulb light because of my project requirement.

Why? What is the project?

Something spectroscopic ? Something needing a blackbody emitter spectrum ?

Surely that would need a slit, not a point?

You might want to condense the light before it hits the slit ?


iceng3 years ago

Put the filament in line with the optical axis

petercd3 years ago

As far as I know, you cant do it because the light source of your bulb is a long coiled filament.

You'd have to start with a single point light source, much like a led or laser.

A well known example is the sun, which can be focused with a magnifying glass, if you try focusing a light bulb with a magnifying glass you just get a small sharp image of the filament.

That's why you use a condenser lens system.

Condenser lenses work well on a small single point of light, typical examples use a filament size of 4mm, the long tungsten filament is going to create a lot of unsatisfactory lens flare if it even works at all.

A lot depends on the size of the lenses relative to the source. In fact, you can get quite nice results even with extended sources.

We don't actually know what the OP is trying to DO with this source either.....

The optical system you want is called a condenser lens.

Vyger3 years ago

A mirrored box (not necessarily a cube, but with multiple reflective surfaves all pointing to a common point.) with a Fresnel lens that has an adjustable focal length. No matter what you do you will not be able to concentrate ALL of the light. Most of it will be converted to heat even with mirrored surfaces. And the lens will also absorb the light and convert it to heat.

m_uamir72001 (author)  Vyger3 years ago

agree !! thanks