# Cylindrical beam spotlight



## Datman (Nov 15, 2017)

Hi all

I want to make a LED spotlight with a target of about 30cm (12 inch) at 3~15 meters (10~50 feet). Battery powering is not needed. I can power it by mains.

Firstly, I thought using lenses. I bought this from Aliexpress:
https://it.aliexpress.com/item/Cool...32698372372.html?spm=a2g0s.9042311.0.0.ZtF0wW
The beam is about 10°. Moving lenses i obtained 6°, at the cost of a less focused border. At 15m the target would be about 1,5m (5 feet). It could be too large.

Now I'm thinking using a parabolic mirror, but it is arduous to find. I don't need a very good optical mirror for telescopes; i need something of about 30cm diameter but not very accurate. Someone made something similar using little mirrors or mirror tape on a parabolic antenna, but a 30cm one is not so common. I could experiment with some metal strips about 32cm (11") long and 3cm (1") wide, each one curved, screwed at the center and opened as an umbrella...

What do you think about?
Can someone help me?

Thanks
Gianluca


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