• 0 Posts
  • 68 Comments
Joined 2 years ago
cake
Cake day: June 13th, 2023

help-circle

  • Hosting NSFW content is an absolute ball-ache, so a lot of instances that are not NSFW focussed do not host it.
    In the early days of feddit.uk, we decided to go the path of SFW, to simplify things.
    I absolutely salute the lemmy-nsfw admins in taking that load on.
    And it makes a lot of sense: If you’re going to deal with the headaches, you might as well focus entirely on them!



  • Maybe the best way to think about it is not dark, but the absence of more light.
    On a DMD projector, we use tiny micromirrors for each pixel which flash thousands of times per frame of video.
    The flash/no-flash ratio decides how much light makes it out of the projector. This gives us over a thousand light levels per colour channel, from near dark, to full light.
    When the mirrors are not in position, the light output is very low. (1/1000th of the full output, on a projector with a static 1000:1 contrast ratio)

    The screen is designed to reflect light well, which means in a non-perfect room, it will have a light floor of the reflected ambient light, plus whatever still makes it through the projector (as Cygnus mentioned, room treatment).

    If you do treat a room well enough that the small amount of light that makes it through the projector at all-off is a problem, you can do things like fitting an ND filter to the lens (reducing the full light output, while also reducing the minimum).
    Or you can use the dynamic iris fitted to some projectors (which reduces the amount of light being put out based on the overall scene illumination, similar to the way LCD TVs lower the backlight level to “reach” contrast ratios of 100000:1).

















  • I kinda agree, lots of different formats in every direction, lots of dividing 1 by numbers to compare things.
    One site lists Wh/mi, another Mi/KWh, manufacturer site only lists the range based on speed.
    Then comparing it to figures for countries using metric distance, customary sized gallons for ICE, and L/100KM…It gets fiddly to make direct comparisons!

    On the efficiency of generation, I guess it’s open to the reader to apply their own modifier.
    I’d be aiming to charge the car using private solar as much as possible which would drive it down.
    National Grid emissions in the UK last year were about 217g/KWh on average. Even using grid the whole time, the emissions would be easily halved for me.

    Edit: There is a suitably lengthy wikipedia page on MPGe. Having skimmed it, MPGe doesn’t take into account upstream efficiency. While well-to-wheel gives a clearer picture, I can understand why for a simple metric MPGe does not. Especially since the primary function will be users gauging cost, and the electricity source should gradually improve over time.