Dimming miniature LED spotlights

Escuta

Member
Joined
Mar 12, 2021
Location
Brazil
Hello,

I'm using miniature 12V, 1-1.5W spotlights inside a diorama. They're dimmable and I'm controlling them with the GPIO pins of a Raspberry Pi computer and simple circuitry. I believe that the response of the LEDs is linear and the intensity is adjusted with values ranging from 0 to 255. My issue is that I'm only using a range of 0 to 10 to illuminate the scenery, perhaps I'll go a little higher. I have no experience with lighting but I imagine that some kind of neutral density filter in front of the spots might help me use the full dynamic range of the intensity control.

Could someone please suggest what kind of filters I might use; ones that won't affect the tight focus of the beams? Cheap solutions most welcome!

If anyone's interested - the lights I'm using are these: tinyurl.com/yey53wmv and the circuitry and software to control them is the same as for these 5050 LED strips: https://dordnung.de/raspberrypi-ledstrip
I'm also using a new open source OSC-based show-control software called OSSIA Score. See: https://ossia.io/score/about.html
I talk about getting the RGB LED strips working in the later posts in the following forum thread: https://forum.ossia.io/t/controlling-led-strips-with-score-and-a-raspberry-pi/212

Thanks!
 

macsound

Well-Known Member
Joined
Jun 15, 2018
Location
San Francisco, CA
I'd say Rosco ND gel ($9 for a 20x24" sheet) but your shortened link for the lights your using didn't work so I'm not sure if there's an easy way to tape or glue to the front.

Another idea, depending on how your lighting is placed within your diorama and how big the diorama is, stretch a piece of makeshift scrim across the whole area where the lights are mounted. Then it will reduce lighting glare and affect all of your lights without having to apply to each individual position.
 

macsound

Well-Known Member
Joined
Jun 15, 2018
Location
San Francisco, CA
I'm at the office today and I guess Aliexpress is blocked.
Knowing how much is kind of trial and error. Since you're using small amounts, start with 1/4 ND and then if you need more you can just stack it.
 

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