Relative brightness of led displays for project


#1

I ordered a Blinkt as an afterthought during a recent parts order, but I am having such fun with it. My first thought was, “damn, that’s bright!”. One of my other hobbies is cinematography, and I started playing with an old lens I had from a viewfinder shade, and what do you know, it focuses the blinkt perfectly across the room. Too well, in fact–I had to put some diffusion filter in front of the LEDs to make the individual colours blend properly. I now have 8 four-inch colour “spheres” on my wall.

So, now I am wondering if I can do something similar with one of the matrix dislpays, either a Scroll Phat HD or the Unicorn HD. I can’t seem to find details on the actual LED components in either of these or (all that really matters) the relative brightness of these compared to the Blinkt. Can anybody help with that so I can decide which to turn into a projector?


#2

Not sure this helps, but I’ve been putting the Ninja Diffuser’s on top of my Sense Hat LED matrix for the same reason. It blends the colors so you don’t see the individual LEDs. Up close I could see pin pricks of RED when displaying say Yellow or White. With the Diffuser all I see is a yellow square. On my Sense Hat I use the sense.low_light = True python command to dim the display in a dark room. I can also do it by playing with the display values for the colors. (255,255,255) is white full bright. (128,128,128) is off white or white dimmed. I’ve never played with Blinkt so I’m not sure you can do similar things.


#3

You don’t answer my main question (which is brighter, unicorn hd or scroll hd), but yes, the idea of auto-adjusting brightness via a sensor is very interesting, so thanks!

The trick with diffusion is to get just enough diffused while allowing the maximum light through. Photographic diffusion “gels” come in a variety of strengths so you can pretty easily find an optimal solution. They are usually made to withstand some heat, being used with old-school 1000W halogen fresnel lamps, etc.


#4

I don’t have a Scroll Hat or Unicorn Hat so I can’t help you there. Jut relaying my personal experience with what I do have on hand. I do believe they mentioned what LED’s were used in the Bilge Tank video on the Unicorn HD. You could hunt that up, or just wait for somebody from Pimoroni to respond.