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leguminous

532 karma · joined December 1, 2018

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leguminous··on Heat Pumps Work Miracles
Air sealing is also critical. The insulation can be defeated if unconditioned air can leak into the house and conditioned air can leak out. It's a difficult thing to get right because it requires attention to detail and if done poorly it can result in moisture problems.
leguminous··on Mark Zuckerberg Speaks Down to Users and Misses the Point
> Most Internet content isn't nearly as "contextual" as a nature magazine. Probably 99% of the content I read won't help target ads much at all, because it's mostly NYT news articles and the like.

The NYT cut behavioral advertising in Europe after the GDPR and still grew revenue:

https://digiday.com/media/new-york-times-gdpr-cut-off-ad-exc...

Edit: I just read the EFF post and realized this article was linked. Did the parent poster mean that 99% of what he or she read was not NYT articles and the like?

leguminous··on Audiophiles in Japan Are Installing Their Own Power Poles
HDMI cables used to be a great example, but now there are something like 8 different levels of certification and only the highest have the bandwidth to carry a 2160p, 60fps, 10 bit, 4:4:4 signal. And as far as I can tell, they are all passive so your source or sink can't warn you that your cable isn't compatible. You'll just get artifacts.

The AmazonBasics cable will do 18Gbps, so it can do 2160p, 60fps, 10 bit, but only with chroma subsampling (which is fine because most video sources have chroma subsampling). The Amazon cable may work with a 4:4:4 signal, but it's not certified for it. There's a level above that for 48Gbps cables.

I totally agree with the general idea, though. As long as a cable for a digital signal meets the specifications set by the standards body, you're good.

leguminous··on 8K is now being broadcast in Japan
There are a lot of comments debating whether 8K is worthwhile vs 4K, and whether we can see a difference. I decided to do some math.

Let's assume someone has a 65in (165cm) TV and sits 6.5ft (~2m) away. This is a larger TV than most people have, and a closer viewing distance than most people sit. Let's also assume that the viewer has 20/12.5 (6/3.75) vision. 20/20 (6/6) is the low end of normal, and it isn't uncommon to have slightly better vision. My optometrist (my fiancée) can correct me to about 20/15, but 20/12.5 is unusually good.

The screen width is 56.65in. At this distance, that subtends an angle of about 40 degrees:

    >>> math.degrees(2 * math.atan(56.65475464133182 / (2 * 6.5 * 12)))
    39.9191582380095
20/12.5 vision corresponds to 48 cycles per degrees, or 96 pixels per degree, distinguishable (20/20 is generally accepted to be 30 cycles per degree). Therefore, the viewer can distinguish 96 * 40 = 3840 pixels horizontally. Which is UHD 4K resolution.

I chose the inputs to get to that result, but my point is that viewers would need to have unusually good vision, and unusually large TV, and be sitting unusually close to hit the limits of 4k. And that's only for very high contrast images, like black text on a white background. Our eyes are less sensitive to low contrast transitions, as found in most videos. Try reading an eye chart with the letters printed in gray on a lighter gray background. It's more difficult!

I think there are much better things we can use our limited bandwidth for than increasing resolution: we could use better compression codecs at higher bitrates, reduce or eliminate chroma subsampling, increase color depth and/or gamut for HDR content, or use higher framerates for content where that is appropriate.

EDIT: Here's a source for 20/20 = 30 cycles per degree, and 20/12.5 vision being unusually good: https://www.opt.uh.edu/onlinecoursematerials/stevenson-5320/...

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