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abirkill

160 karma · joined March 25, 2013

[ my public key: https://keybase.io/abirkill; my proof: https://keybase.io/abirkill/sigs/ChP31BIVjRTWkY03dHtvqUNu_4PI_ebmCAqRBVDyvJ4 ]
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abirkill··on Matrox: Graphics for Professionals
Founded in 1976 by Trottier and Matić, and according to the article and Wikipedia, since 2019 has been owned 100% by Trottier. There's no indication that the founders lost majority ownership at any time, and although they sold off one division in 2019, it appears that Trottier still owns 100% of the remaining two divisions today.

That's pretty remarkable, isn't it? How many tech companies that had a period of being a household name have lasted 50 years and are still majority-owned by all or some of the founders?

abirkill··on BS 1363 British Plugs and Sockets
I found that there's a surprising difference in quality for what feels like it should be a commodity item. All the outlets in my newish build were tamper-resistant, and pretty much as you described -- at best they were unpleasantly stiff and awkward to use, and some specific outlets would require a worrying amount of force and wiggling to plug anything in.

After a couple of high-usage outlets got jammed to the point that nothing could be plugged in, I replaced them with ones from the hardware store, and they are a big improvement. The existing outlets are unbranded, and I guess were from a bulk box of the cheapest that the electrician could source.

In my experience, Leviton are OK (much better than what was originally fitted), but Eaton are great -- they require slightly more force than non-TR outlets, but they're consistent, reliable, and I've never had to try more than once to plug anything in.

abirkill··on Reverse engineering the Sega Channel game image file format
This is not a dissimilar system to Teletext[1], which transmitted data in the blanking interval of a broadcast TV signal, and could be interpreted by a TV or other hardware with appropriate support. Teletext was pretty widespread throughout Europe in the 1980s and 1990s.

It was typically used to transmit pages of information (news, weather, etc.) that could be viewed directly on the TV, but the BBC's Ceefax[2] Teletext service was also used to distribute software to the BBC Micro, when equipped with the appropriate Teletext Adapter[3].

In a similar fashion to the Sega Channel system, the Teletext system would broadcast looped data, with popular pages (such as news and weather) being repeated frequently so they would load quickly, and less popular pages taking longer to load (or more accurately, to wait for the next time they appeared in the looped data).

I was interested to see that the Sega system used a bitrate of 8Mbps, which sounded pretty high for the mid-90s, but I see that Teletext had a bitrate of almost 7Mbps for PAL broadcasts, despite being roughly 15 years older!

[1] https://en.wikipedia.org/wiki/Teletext

[2] https://en.wikipedia.org/wiki/Ceefax

[3] https://en.wikipedia.org/wiki/BBC_Micro_expansion_unit#Telet...

abirkill··on Why Google Takeout is sooo bad
I can't speak to the cloud provider support, as I don't use it, but they have supported scheduled backups since at least June 2019, as I have locally-stored backups from scheduled Takeout jobs going back that far.

Bear in mind that the scheduling support is extremely basic -- the only option available is to schedule six exports, one every two months. You can't change the frequency or the number.

Also, you can't pick when the schedule starts, so if you want backups every two months indefinitely, you have to remember to schedule the next set of backups two months after the final backup of the previous scheduled job finished.

It's better than nothing, but only just.

abirkill··on My favorite 1980's Canadian TV show: Bits and Bytes
There were also several others, including some live shows, all of which can be found on the BBC's Computer Literacy Project Archive: https://clp.bbcrewind.co.uk/

During one of the live shows, demonstrating e-mail, the e-mail account was hacked, probably the first hack captured on TV: https://www.vice.com/en/article/9ak7w5/as-seen-on-tv-when-ha...

abirkill··on The U.S. government may finally mandate safer table saws
I think the speed that things can go wrong when using a table saw (or most power tools) is faster than some people, including some woodworkers, might expect. There's a good example video here (warning, shows a very minor injury):

https://www.reddit.com/r/Carpentry/comments/11s6zlr/cutting_...

While we're still not talking microseconds, I think it highlights that moving the blade out of the way needs to happen very quickly in some cases to avoid serious injury.

abirkill··on Lawyer cited 6 fake cases made up by ChatGPT; judge calls it “unprecedented”
Churchill was also prime minister from 1951-55.
abirkill··on An Example of a Sad Google Account Recovery Failure and Its Effects
As a counter-example, I haven't had an entirely successful Google Takeout export in at least a couple of years, using their service to schedule the exports automatically every two months.

I always have a failure with Google Fit data, which reports 'Service failed to retrieve this item' on the same JSON file every time. I assume this is something corrupted at their end.

It's not that uncommon for my exports to intermittently show failures with other services -- for example, my latest export, taken on April 20th, also failed to include one of my YouTube videos, with the same 'Service failed to retrieve this item' error. That video is usually included successfully, so I'm guessing this was a glitch.

Nothing major, but I can well believe that others also experience regular errors, although I'm sure we're in the minority.

abirkill··on Training my sense of CO2 ppm
This is true, but I don't think any consumer-grade sensor systems offer this as an option? I guess it might be useful if you're building your own sensor, and can't afford/justify a dual-NDIR sensor.

My understanding is that with single-NDIR sensors (like the MH-Z14 and 19), the auto-calibration is intended to overcome gradual particle buildup and beam degradation in the sensor chamber. While disabling it will prevent the scenario I described, you'll instead end up with gradual sensor shift as the sensor ages. I guess this could be minimised by manually calibrating the sensor outdoors on a regular basis.

Dual-NDIR sensors split a single beam into two chambers, so any degradation of the sensor beam affects both measurements, and the particle buildup in both chambers should also be approximately equal over time, so they should remain accurate over an extended period without any requirement for calibration. I built mine about 4 years ago and I do occasionally check to make sure they read ~400ppm when placed outdoors, last check was around 420ppm which suggests they're behaving reasonably well as they age.

abirkill··on Training my sense of CO2 ppm
That's a shame, they've worked well for me. Unfortunately I can't recommend any others without doing some research, I found quite a few dual-NDIR sensor modules when I was looking and chose this one primarily based on availability and a reasonable datasheet.

A sibling post[1] mentioned a sensor that is listed as being dual-NDIR so should give reliable readings, and has a USB interface, so that sounds like one possibility.

[1] https://news.ycombinator.com/item?id=32122301

abirkill··on Training my sense of CO2 ppm
The auto-calibration systems on cheaper consumer sensors also cause issues if they rarely see air that has low CO2 levels. Because these sensors can't measure absolute CO2 levels, only relative CO2 levels, they provide an absolute figure by looking for the lowest CO2 concentration they've seen over a period of time, usually around a 72 hour rolling window.

This works acceptably if the sensor is frequently exposed to outdoor air, but in a residential environment that's not always guaranteed, particularly in winter when it's not uncommon to keep windows closed to retain heat. In these situations the sensor will consider the lowest level to be around ~400ppm, even if it's actually much higher. This, of course, scales all other readings, so a sensor might read between 400-800ppm, leading you to believe everything is fine, when the actual indoor range is 800-1600ppm.

Because the auto-calibration happens over a period of time, it can be quite difficult to determine that your sensor is misreading, and the only way to fix it is to expose it to fresh air to reset the baseline.

The best solution I found to this is a dual-NDIR sensor which measures two different light frequencies, one which is absorbed by CO2 and one that isn't. This allows the sensor to know the absolute CO2 concentration, rather than the relative CO2 concentration, and avoids the need for auto-calibration. (I believe for absolute accuracy it still needs calibration for altitude, but for consumer use this makes such a small difference to be irrelevant).

Unfortunately, when I last looked, I couldn't find any consumer-grade sensors which used dual-NDIR sensors, only more expensive and less aesthetic commercial sensors. In the end I built my own using a CDM7160 sensor connected via I2C to a ESP8266, which reports over MQTT.

abirkill··on Canada's 'gamble' on delaying, mixing and matching Covid-19 vaccines paid off
Out of the three vaccines in use in both Canada and Europe, it appears that Canada entered agreements as follows:

  Moderna: August 5th, 2020 [1]
  Pfizer: August 5th, 2020 [1]
  AstraZeneca: September 25th, 2020 [2]
Europe entered agreements as follows:

  Moderna: November 25th, 2020 [3]
  Pfizer: November 11th, 2020 [4]
  AstraZeneca: August 27th, 2020 [5]
I couldn't immediately find data on the quantities ordered, but this doesn't seem to support the claim that Canada was slow in placing orders?

[1] https://www.canada.ca/en/innovation-science-economic-develop...

[2] https://pm.gc.ca/en/news/news-releases/2020/09/25/new-agreem...

[3] https://ec.europa.eu/commission/presscorner/detail/en/ip_20_...

[4] https://ec.europa.eu/commission/presscorner/detail/en/ip_20_...

[5] https://ec.europa.eu/commission/presscorner/detail/en/ip_20_...

abirkill··on Waymo pulls back the curtain on 6.1M miles of self-driving car data in Phoenix
From the second paper[0]:

'In order to provide more information about event severity within the S1 designation, S1 severity events have been separated into two columns in Table 1 based on whether each event is of sufficient severity to result in actual or simulated airbag deployment for any involved vehicle. Of the eight airbag-deployment-level S1 events, five are simulated events with expected airbag deployment, two were actual events involving deployment of only another vehicle’s frontal airbags, and one actual event involved deployment of another vehicle’s frontal airbags and the Waymo vehicle’s side airbags. There were no actual or predicted S2 or S3 events'

[0] https://storage.googleapis.com/sdc-prod/v1/safety-report/Way...

abirkill··on Waymo pulls back the curtain on 6.1M miles of self-driving car data in Phoenix
They're using the ISO 26262 scale for severity, not their own: https://en.wikipedia.org/wiki/ISO_26262#Part_9:_Automotive_S...
abirkill··on Canada to bar entry to non-residents (except US)
Another interesting example is Hyder, Alaska, which is only accessible by road from BC, Canada. It relies on various services from Canada, including ambulance and fire services, the latter due to Hyder's fire hall being burnt down, with their fire engine inside, during an Independence Day fireworks display.

There are no border controls when entering Hyder from Canada, as the only way to access the rest of Alaska from Hyder is via seaplane, and those flights are treated as international in origin when they land. There is a inspection station when crossing into Canada, but it is closed overnight -- anyone wishing to enter Canada when its closed must report via videophone.

abirkill··on Facebook tracks your private calls
As a counter-example, I requested mine about 20 minutes ago, received an e-mail confirming the request, received another e-mail 6 minutes later to say it was available for download, and the ~90MB download completed in under 10 seconds on my 150Mbps connection.
abirkill··on Dark Site Finder: tracking light pollution to find locations for stargazing
From the location of those light sources, I suspect they are from drilling rigs extracting oil from several large oil fields around the Grand Banks of Newfoundland.

There's a map of the largest fields in this article:

http://www.cbc.ca/news/canada/newfoundland-labrador/husky-we...

abirkill··on iPhone X
If you're simply looking for capacitive touch in a consumer environment, then there are a great many. Simple capacitive touch sensors to replace physical push-buttons were widely seen in the 80s, I remember using them on elevators, and built one myself as a child.

Capacitive touch sensors that registered an X/Y position rather than a simple on/off state were also common in laptop touchpads from around the mid to late 90s. The iPod introduced a capacitive touch wheel to replace the click wheel in their second-generation model, released in 2002.

There were various capacitive touchscreen display devices around before the iPhone, but probably the most relevant to your query (and one of the most well-known, due to its similarity to the first iPhone's technology) was the LG Prada, a phone with a capacitive touch-screen announced about 6 months before the iPhone.

The thing with the iPhone's touchscreen wasn't that the technology was particularly revolutionary -- sure, if you combine enough words together, then you can make the argument that the iPhone was probably the first mass-consumed capacitive multi-touch hand-held consumer device, but you can remove any of those words and it was no longer the first. The revolutionary aspect of the iPhone was, in my opinion, the software that allowed the device to be controlled with the relative imprecision of a finger, rather than a stylus. The actual hardware to process the touch inputs was at best evolutionary, not revolutionary.

abirkill··on Amazon recalls eclipse glasses
If yours also claim to be manufactured by American Paper Optics, as the pair in the parent comment claim to be, the (real) manufacturer has some information to help determine if they're counterfeit:

https://www.eclipseglasses.com/pages/safety

See the photo at the very bottom of the page for an illustration of the (very minor) differences.

abirkill··on Amazon recalls eclipse glasses
Many libraries have received glasses for free from the Space Science Institute, which is a reputable organisation funded by NASA, the National Science Foundation, and others.

There's a map of libraries on their website:

http://spacescience.org/software/libraries/map.php

If yours is on that list, you should be pretty safe, I think.

abirkill··on Amazon recalls eclipse glasses
This isn't limited to glasses. I purchased a 12x12 sheet of solar filter film from a seller on Amazon, manufactured by Thousand Oaks Optical (who are listed on the American Astronomical Society's list of reputable vendors), and I'm also being refunded.

I checked the Thousand Oaks Optical site and they have a list of legitimate resellers of their products, and the Amazon seller I used is listed. I'm surprised Amazon didn't do the same basic checks before e-mailing me.

When I was searching for more information after receiving the e-mail, I also found someone on an astronomy forum[1] who is being refunded for a telescope that appears to retail for around $1199.

[1] https://www.cloudynights.com/topic/587658-amazon-eclipse-gla...

abirkill··on First large-scale deep-sea floating offshore wind farm
As an example, the Vestas V164-8MW seems to be one of the largest off-shore wind turbines, and has a rotor diameter of 164m and a rotational speed of between 4.8 and 12.1rpm. [1]

Unless I'm miscalculating, that means that the tip of one of the rotors will travel 515 metres per revolution, which at 4.8-12.1rpm is a tip speed of between 2,472 metres per minute and 6,231 metres per minute.

To put that in more common units, that's between 148km/h and 373km/h.

[1] https://stateofgreen.com/en/profiles/vestas/solutions/v164-8...

abirkill··on Herman Miller Launches New Aeron Chair
I had the same issue with the seat edge, I believe that it's referred to as a waterfall edge. The rest of the chair was great, but I found that extremely uncomfortable after a few hours. Many people don't have a problem with it, however.

I also recommend Steelcase as a good alternative. I considered the Leap but eventually chose the Gesture, and am extremely satisfied.

abirkill··on Rolling Shutters
YouTube's stabilisation option attempts to remove (with reasonable success, in my experience) rolling shutter wobble caused by camera movement, although I don't believe it will mitigate the effect of a moving subject.

There was a talk at last year's Google I/O with some examples:

http://youtu.be/QdXugkXBTbc?t=15m56s

abirkill··on Show HN: Give 7 billion people a physical address
Not all houses in the UK have numbers, especially in rural areas. If you don't live in a village or larger, it's pretty common to have a house name, and no number. (Edit: I just checked the village I grew up in, and was surprised to find that out of 48 houses covered by the postcode, 41 of them only have a house name, no number -- I'd have guessed closer to a 50/50 ratio).

Even in cities, it's not particularly unusual to have houses that don't have numbers, especially older houses -- in my parents' postcode, two of the houses only have a name.

House names are fully supported by correctly implemented postcode lookup systems -- for example, in the common online use-case where you enter your postcode and a list of houses is brought up, the list will include the houses that only have name identifiers.

abirkill··on Time lapse of all nuclear exlosions from 1945 - 1998
The vast majority, but not all, I don't think?

Wikipedia states that the most recent atmospheric test detonation was carried out by China in 1980, although the reference link appears to be broken:

https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests#...

abirkill··on Apartment Blockers: Parking Rules Raise Your Rent
There is at least one residential building in Vancouver, BC that has implemented an automated system, but according to this article, the cost per space is almost double that of a conventional space:

http://www.vancourier.com/news/vancouver-robo-garage-lowers-...

Also, having spoken to someone who lives in that building, it seems to be disliked by a lot of residents, due to the long waiting times at peak periods. That's not particularly surprising given there are only two transfer stations.

I guess these systems may work better in retail locations where there is a steady flow of traffic coming and going through the day, rather than at residential or office locations where there are very high peaks in demand. To build enough transfer stations to satisfy the peaks would presumably both be very expensive, and reduce the space savings that were made.

abirkill··on The Bay Bridge is gradually disappearing from Google Maps
On a similar vein, I was very impressed to note that, when the I-5 bridge over the Skagit River in Washington collapsed in May this year, it took roughly 1-2 hours from the news breaking (around 7:00pm PDT) for Google to have removed that section of the I-5 from their maps.

I would be very interested if anyone has insight on how it was done so quickly (particularly as to whether it's some automated process driven by a reliable data feed, or whether human intervention was required). It seemed too quick to be instigated by Map Maker edits, but maybe if enough people submit the same change, updates are pushed through faster?

abirkill··on The demise of the DSLR
I'm very familiar with phase-detection autofocus on the sensor, and I absolutely agree that this is very likely to be the primary technology in the future, but it's not yet capable of providing the required focusing performance for serious wildlife or sports photography.

All of the systems currently widely available are what are called hybrid systems, because the on-sensor phase detection alone is not sensitive or accurate enough to work on its own in a wide enough range of conditions. They use the phase detection to get the lens roughly in focus, which then allows the contrast detection to work over a very small range of possible values, and allows the combined focusing to be both fast and accurate. (There are various claims online that the 70D, which uses the new sensor you mention, isn't a hybrid system, but Canon's own specs state it still uses some contrast-detection in live view mode[1], so my understanding is that it's simply doing more phase-detection and less contrast-detection than earlier systems, rather than being 100% phase detection)

As an example of how unsuited these systems currently are to sports or wildlife photography, in the Canon 70D, there is no way to enable proper continuous autofocus when using live view to shoot still images. Tracking is only available in movie mode.[2]

The camera can continuously provide a rough focus[3] (which speeds up final focus acquisition, and is also probably the exact same system used for movie focusing -- see below), but this is not accurate enough for reliably in-focus shooting. (Behind the scenes, this will almost certainly be using the on-sensor phase detection only).

Whichever mode you half-press the shutter in, the camera will then perform a precise focus (behind the scenes, it's almost certainly using the phase detection data combined with contrast detection data), but at that point, regardless of which of the modes you are in, the focus is locked -- if your subject moves closer or further away, you will need to release and re-press the shutter to regain accurate focus. I'm sure you'll appreciate that if you gave this system to anyone other than an extreme amateur sports or wildlife photographer, they wouldn't touch it.

(Note that the 70D does include a 'tracking' mode[4] in live view, but this merely uses face detection to ensure that the focus area is constantly over a face in the image, it doesn't cause the focus to adjust should the camera-to-subject distance alter while the shutter is half-pressed)

When you're shooting movies, of course the camera will track focus, but while it does a pretty good job compared to previous systems, it's very easy to see how bad the system would be for still photos. Take a look at this example footage[5], where it's very easy to see that the autofocus system is not performing anywhere near what would be required for action photography -- even at the default Youtube size and resolution (without needing to view it full-screen), the inaccuracy and big jumps are very easy to see, on a subject that is moving very slowly and predictably. And that's in pretty excellent light, not an indoor stadium or under trees in overcast conditions. (Also remember that that video is very clearly out of focus at times at a resolution of just over 2 megapixels, and when you're shooting stills you're expecting it to be sharp at 20 megapixels)

As I say, I think it's very likely that improvements to the on-sensor phase detection, as well as algorithmic improvements to the blending of the phase-detection and contrast-detection data, will mean that this is the future of action photography, but it's not there yet, and personally I'd say we're probably 2-3 generations away from a system that can track action as well as even a low-end DSLR that uses a separate dedicated phase-detection sensor.

[1] http://gdlp01.c-wss.com/gds/5/0300011965/01/eos70d-im-en.pdf (Page 436)

[2] http://fr.canon.ch/Images/Dual_Pixel_CMOS_AF_Tech_Explained-...

[3] http://gdlp01.c-wss.com/gds/5/0300011965/01/eos70d-im-en.pdf (Page 228)

[4] http://gdlp01.c-wss.com/gds/5/0300011965/01/eos70d-im-en.pdf (Page 233)

[5] http://www.youtube.com/watch?v=gMMwNZYRT2A

abirkill··on The demise of the DSLR
Isn't that somewhat sweeping? Sure, for some types of photography, getting a shallow depth of field is rarely a concern, but in other disciplines, a shallow depth of field is highly desirable.

Many wedding and portrait photographers have at least experimented with the Brenizer Method[1], the sole purpose of which is to create an image with a shallower depth of field than is otherwise possible, and replicate the appearance of large-format photography.

[1] http://en.wikipedia.org/wiki/The_Brenizer_Method

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