* Posts by Steve Todd

2004 posts • joined 19 Sep 2007

Mono Magic: Photography, Breaking Bad style

Steve Todd
Silver badge

Re: Foveon

You're assuming that Foveon sensors are perfect also. They are not. There's a lot of crosstalk between Red, Green and Blue. The blue channel contains large red and green components. Green contains a lot of red etc. It's this crosstalk, plus manufacturing variations, that cause the colour inaccuracies that I was talking about.

Modern CFAs deliberately introduce some crosstalk between adjacent colours themselves, so each photodiode gives more spacial information, plus the filters are formed into lenses to increase the amount of light hitting each photodiode. The result is higher light sensitivity and a more predictable colour response than Foveon types.

Use your Sigma and be happy, just remember that there are reasons that most of the photographic world uses CFAs and are happy with them. (And no, I don't work for a CFA manufacturer, nor any photographic company. Nor do I employ other accounts for down/up voting)

0
0
Steve Todd
Silver badge

Re: Foveon

In photography there's no arguing against someone who says "I like it". It's a personal preference and you can't say someone doesn't have it. What you can do is to point out when their reasons given for liking something are incorrect. I've never come across colour Moire patterns on a conventional DSLR, but far more objectionable are chromatic aberrations and lens distortion. Both of those can be corrected out by a decent RAW converter, but the only converter available for Sigma Foveon cameras is lacking in those facilities, is slow and badly written.

0
0
Steve Todd
Silver badge

Re: Foveon

Firstly that's a 180 degree about face in your position, you claimed that Foveon sensors made all the difference between film and digital.

Secondly he IS wrong. Take a digital image, add the right contrast, saturation and curves, add grain effect noise and you'd be hard pushed to spot the difference between film and digital. You can take sublime photos on a cell phone, never mind a modern DSLR or film camera.

Thirdly the lack of an anti-alias filter is a cheat in any analogue to digital conversion (sound, images or whatever) as any detail above 1/2 the sampling frequency will produce false artefacts. Go look up Nyquist's limit, this explains the problem. The lack of the filter produces false lines and repeats when you get close to or above the limit on the Sigma. You don't get blotchy colour, but it's still wrong.

Distortions and noise are easy to add. Not so much to remove. A good camera system concentrates on getting as close to perfect as possible, and lets you do what you want with the images afterwards. There are many great photographers of the past who relied on the printing process and what they added there to lift their work above the ordinary. Digital makes this faster and easier.

1
0
Steve Todd
Silver badge

Re: It is techno-Luddism

@Nigel

Unless you like the smell of the chemicals (which I found moderately unpleasant) and have the space for a dedicated darkroom then you're better off learning how to use RAW format on a DSLR (or on of the better bridge cameras). This gives you full control over converting the data from the sensor into a displayable image with nothing needed but a PC.

0
1
Steve Todd
Silver badge
Stop

Re: Foveon

I started using film cameras over 35 years ago. I've used medium format and 35mm, B&W (which I did my own darkroom work for) and colour. I've been involved in digital photography since the days of the Kodak DC1, have had a DSLR since the Cannon 20D and have seen and compared Foveon images with conventional Bayer. Foveon sensors still need an anti-aliasing filter to prevent Moiré effects, but look less ugly than colour Moiré that you get from Bayer so Sigma cheat and don't use one. The result is a sharp looking image (with Moiré if you look) but poor colour discrimination (it tends to confuse reds and orange for example). Reduce the size of a Bayer image by about 20-30% along an axis (with sharpening) and it looks at least as good, and you still have more pixels.

The only manufacturer who tried Foveon (Sigma) seems to have given up the battle (last updated over 2 years ago IIRC), and their cameras were slow, clunky and unable to handle above 400 ISO equivalent.

0
0
Steve Todd
Silver badge

Re: Foveon

Bayer filters aren't the problem that you seem to think. They mimic the way in which the human eye works, with less sensitivity to colour data than intensity. Foveon sensors are worse at colour discrimation and accuracy, plus they don't even come close to matching Bayer type sensors for detail (divide Bayer pixels by about 1.6 to get equivalent Foveon (real, not counting R, G and B separately) pixels.

1
1

Apple's portable power podule patent promises paroxysms of fanboi joy

Steve Todd
Silver badge

Re: I don't get it

Patents are for "a method". The patent isn't on fuel cells, they've been around for some time. This patent appears to be for a method where the mobile device charges AND communicates with the fuel cell pack at the same time, allowing it control over charging and access to info like the fuel level.

2
5

China's BYD ramps up 'leccycar battery production in challenge to Tesla

Steve Todd
Silver badge

Re: Battery life is an issue on the Tesla?

LiFePo - Lithium Iron Phosphorus.

0
0
Steve Todd
Silver badge

Battery life is an issue on the Tesla?

Last thing I heard they were exceeding their target of 80% of original capacity after 8 years of use.

Lithium iron cells have the advantage of being safer, with no tendency towards thermal runaway. They have the distinct disadvantage of significantly lower energy density, so you need a bigger, heavier battery pack for the same range.

2
0

BBC: We'll give FREE subpar-Raspberry-Pis to a million Brit schoolkids

Steve Todd
Silver badge
FAIL

Re: Ha @codejunky

Scientific bias isn't banned by their charter. Political bias is. I can't say that I like their stance on a number of scientific issues, but that doesn't make them wrong or bad. My taxes pay for scientific research that is biased against my views too, that doesn't mean that I should be able to opt out of paying for them.

These machines will be used at school. No matter how poor a child is their school will have rooms full of PCs that they can use these on. Chances are their local library will also have machines able to program them. This is not an equality issue.

The Pi on the other hand requires the machine, an SD card, a PSU, a HDMI cable, a HDMI capable TV or monitor, a keyboard and a mouse. Minimum that's going to add up to 10x the cost of this device and there are far fewer kids who could use it at home.

1
1
Steve Todd
Silver badge

Re: What can you do with a 74HC00?

Letting them loose on a simple CPLD might be fun. A MAX V 570 for example should give them enough logic to build a CPU for about £5

0
0
Steve Todd
Silver badge
FAIL

Re: Ha @codejunky

The BBC isn't allowed to be biased against a particular party. That doesn't mean that individual programs cant be biased, but as a whole their output must be unbiased. They tend to show bias and take a stance on particular issues (global warming for example), but then so does any news agency you care to mention.

As to existing educational projects, think of this as an intro to those who will move on to the Pi, Arduino, mbed etc. The device is small, simple and cheap. It's there to introduce the fundamentals of computer hardware and programming. Its for kids who have just started secondary school, and you don't want to throw them in at the level of how to program a GUI at that age, you want to get them hooked on the ideas and wanting to take things further.

Costs? The BBC isn't paying for the hardware. The partner companies are. All the BBC are doing is creating some educational programs to teach kids how to use them. That's definitely in their remit.

4
1
Steve Todd
Silver badge
Stop

Re: Ha @codejunky

You missed the bits about "Inform and Educate". Being at arms length from the government its a damned site better than any state funded news organisation, and normally better than ITV news. It's also hard to argue against its role in education, which is what this whole thread is about.

4
2
Steve Todd
Silver badge

Re: Ha @codejunky

Listen out for that whooshing noise. It's the sound of the point going over your head. Many people in the country don't like Trident, but the government decided to fund it in the public good so their taxes go towards paying for it.

Likewise the BBC is held to be a public good (entertainment is just one of the three legs it is built on). Because of that the public has to pay for it, like it or not. Democracy is like that. Don't like it? Move county.

17
3
Steve Todd
Silver badge

There's a little more info

over here http://www.bbc.co.uk/mediacentre/mediapacks/makeitdigital/micro-bit

Looking at the picture and backers list I'd guess it was an entry level ARM M0 connected to an nRF24L01+ radio chip and a simple LED matrix. Less than £5 to build in that volume would be my guess

3
0

Apple Watch: Wait a minute! This puny wrist-puter costs 17 GRAND?!

Steve Todd
Silver badge

Re: Overpriced?

Not it you want it to still work you don't. The oil on the bearings has a limited lifespan to start with, it needs to be stripped down completely, cleaned, re-lubricated, re-assembled and re-calibrated unless all you want is an expensive wrist ornament.

0
0
Steve Todd
Silver badge

Re: Overpriced?

Rolex watches need an expensive service every 2 years and, even brand new, they are way less accurate than even a cheap quartz watch. They are every bit as much about being a status symbol as one of these Apple watches.

1
1
Steve Todd
Silver badge
Stop

Re: Worth it's weight in Gold.... @Metrognome

Plating? The whole point about the Edition version is it's machined from solid 18K Gold alloy (an alloy that Apple have toughened up compared to standard 18K Gold). If they sell it in the UK I'm assuming it will have to be hallmarked. We're talking 1,000s in raw materials before they start the machining process.

0
0

Intel SoCs it to 'em with new D: Tiny but powerful

Steve Todd
Silver badge
Stop

Re: Cheaper PCs/Servers was how x86 got a look in

Unfortunately for you and Intel that number is closer to 1/2 than 1/10, and the newly anounced A72 core reduces that lead significantly. The other, rather large factor that you're ignoring is that companies can get ARM based chips made to specification, with precisely the onboard IO support that they require rather than Intel's one size fits all approach. This makes the complete system cheaper by more than the cost of the CPU. I do hope you aren't resting your pension hopes on Intel.

1
0
Steve Todd
Silver badge
Stop

Cheaper PCs/Servers was how x86 got a look in

Mainframes were displaced by Mini Computers. Mini Computers were displaced by workstations. Workstations were displaced by x86. Why do you insist that x86 is immune?

These Xeons are 45W parts. Current technology ARM 64 chips draw about 4-5W for a 4 core CPU with onboard IO. 40 physical cores on the same energy budget as one 8 core Xeon?

All they need do to take a large chunk of market share is to be fast enough, have software support and be cheaper.

7
1

Elon Musk insists Gigafactory's ALL GO as China charging fears hit Tesla shares

Steve Todd
Silver badge
FAIL

Re: China

Have you done the sums? You could run a domestic 3kW air conditioning unit at 100% continuously from the Tesla battery for 28 hours. In practice you'd get longer than that as it won't run at 100% continuously and you don't need a 3kW plant for a cabin the size of a car.

5
1

UK spaceport, phase two: Now where do we PUT the bleeding thing?

Steve Todd
Silver badge

Re: two options

There is Machrihanish airfield, that was certified for use by the Space Shuttle (as an abort site) and has a 10,000ft long runway.

1
0
Steve Todd
Silver badge

Re: North East

Or maybe Durham Tees Valley airport? Due to management incompetence it seems to have 2 or 3 scheduled flights per day, but RADAR/ATC left over from when it was an RAF reserve base so it handles most of the traffic up to Newcastle and down to Leeds.

1
0

Nokia boss smashes net neutrality activists

Steve Todd
Silver badge
Stop

@Donn Bly

You're dead wrong there. If an ISP can provide a decent technical justification why, for example, Bit Torrent traffic is being slowed, and it is only being slowed enough to cut congestion, then there isn't a problem. Comcast's justification and amount of throttling didn't meet that standard. VOIP on the other hand is low bandwidth and predictable in its nature. You'd need a LOT of connections before VOIP flooded a network, and even POTS has connection limits.

3
0
Steve Todd
Silver badge
Stop

He seems to have failed to understand

What net neutrality is. It does allow for the prioritisation of packets. What it doesn't allow is PAID prioritisation (and that includes prioritising companies in which the ISP has a financial interest above similar services). If VOIP packets get priority then ALL VOIP packets are treated equal, no matter where they came from.

21
1

NO ONE is making money from YouTube, even Google – report

Steve Todd
Silver badge

Apple did this when? They offered to sell tunes on the iTunes store for a fixed 30% fee. Labels are free to withdraw from this deal, set the price band of their music etc. What they did, that the Labels didn't like, was to unbundle tracks. It turns out that the buying public did like this and the Labels made lots of money this way.

Next they offered the Labels money for the right to provide cloud storage for tracks that users had already bought or obtained from elsewhere. Free money for doing nothing.

Finally they have been working on deals for streaming on demand. I've not heard of them making other sales conditional on being involved in this program (which would probably get them in trouble for abusing their position in the market).

The only ones ripping off the artists are the Labels.

23
7

Qualcomm bungs ARM's beefy 64-bit A72s into new mobe brains

Steve Todd
Silver badge
FAIL

Re: @JamesTQuirk

You seem to be trying to change the subject. Non of the A80 boards that I have seen are much less than £100 each, but they would need to cost less than £10 each to be competitive with a desktop GPU in terms of FLOPS/£.

Your original point was that the Qualcomm chips (also ARM based) wouldn't sell. My point was that they were much faster than the A80 you were holding up as an example of Chinese technology that was going to kill it, and that they were aimed at a different market segment (the A80 isn't really targeted at cell phones). Because of this I expect them to sell in huge quantities inside of Chinese cellphones (the Chinese don't really care where they get their parts from, just how they effect the saleability of their devices).

You also seem to be trying to make out that my attitude makes me a Wintel stooge. What? Saying that desktop is more powerful than mobile (demonstrably true) and that the Chinese don't make the best ARM chips makes me a Wintel fan? Time to take your head out of your arse.

1
0
Steve Todd
Silver badge

Re: @JamesTQuirk

Anyone mining bitcoins with a GPU these days is going to be disappointed. They were surpassed by FPGAs some time back, and they were surpassed by ASICs. The GPU in the A80 tops out at about 68Mflops. The ATI 7970 desktop GPU has 2048 cores and tops out at about 3800Mflops. You'll need a LOT of A80s to match just one, and they aren't THAT much cheaper.

I'll say this once again as you're apparently not understanding. These chips are many times faster than the A80 for general tasks, contain most of what you need to make a phone (including 3G and LTE radio) and will be used by the Chinese in large quantities (think millions) for higher end phones.

0
0
Steve Todd
Silver badge

Re: @JamesTQuirk

Not according to Allwinner's web site, and given that ARM's design for big-LITTLE allows for up to 4 of each type, I'd suspect your information is wrong.

You're also lacking in understanding on how GPUs work. Not all GPU cores are equal. Just "having 64 GPU cores" doesn't make it a fast GPU, and GPU cores are normally useless for general compute tasks. The standard Adreno GPU has 128 ALU cores these days, but the PowerVR is a better chip. On the other hand it can't hold a candle to the latest desktop GPU cores.

The other point is that the Qualcomm models are designed for mobile comms devices (phones or pads), not All-in-one boards. Chances are that a lot of Chinese phones will contain them.

0
0
Steve Todd
Silver badge
Stop

@JamesTQuirk

Do you know ANYTHING about ARM processors? The A80 is 8 core, yes, but using the older ARM V7 architecture that is 32 bit only. The A72 in the Qualcomm chips is rated by ARM as 3.5 times faster than the A15 (the "big" side of the A80), uses the newer ARM V8a instruction set and is full 64 bit. It doesn't even compete in the same market space as the A80 as the A80 has no in-built cellular modem like Qualcomm's chips.

0
0

Qualcomm, ARM: We thought we had such HOT MODELS...

Steve Todd
Silver badge

I'm not sure that ARM are in trouble here.

They either licence the IP for their processors, IO interfaces etc, and charge a small fee based on what each individual client is using (certainly too small a fee to be worth most clients developing their own processors) or let the client build their own compatible designs for a lessor fee. They don't force you to use their components (want to use PowerVR rather than Adreo graphics cores, no problems) and the costs are only based on the components used on chip, not the final device.

Qualcomm are a different matter however. They're going to have to resign themselves to charging per chip, not on the end-user price as the IEE is pushing for.

6
0

Meerkats helped Ofcom unlock White Space spectrum-hopping

Steve Todd
Silver badge

Actually it does both. It has a list of frequencies for a given area, then it looks out for unlicensed kit working on the same channel and hops about to reduce interference with that. As it's highly improbable that all 48 channels (or even close to that number) will be licensed in a given area then it's a non-issue.

0
0
Steve Todd
Silver badge
Stop

@boltar

1) DTTV can fit 4 HD streams into a single 8MHz channel.

2) There are 48 channels allocated to TV at the moment.

3) There are 10 digital multiplexes in the UK, not all of them working in a given area.

4) 802.11b/n (the 2.4GHz version most people use) has only 3 distinct channels available, 5GHz has 16 non-overlapping channels available here in Europe.

0
1
Steve Todd
Silver badge
FAIL

An apt handle. Radio gear already knows how to monitor for traffic and switch to a different channel if the current one is busy (it's part of the spec for 5GHz 802.11ac). You think there's only one or a couple of spare frequency slots in white space?

0
2

BT coughs £12.5 billion for EE as fourplay frolics pay off

Steve Todd
Silver badge

Well, that's what passes for EE customer support ...

completely trashed then. I suspect my contract won't be renewed with them.

5
1

Zimmermann slams Cameron’s ‘absurd’ plans for crypto ban

Steve Todd
Silver badge
Stop

Re: The Point

The government sees a need for official secrets, which it won't disclose to the public until 50 or more years after the fact (or not at all in some cases). If it's ok for them to have secrets why can't we have them?

19
0

Crackdown on eBay sellers 'failing to display' VAT numbers

Steve Todd
Silver badge
FAIL

Re: Imports from outside the EU

They do if the seller hasn't lied on the customs declaration. Having a VAT number will stop them lying on their paperwork will it?

0
0
Steve Todd
Silver badge

Imports from outside the EU

Already get import duty plus VAT applied to them on entry. How is this going to reduce the foreign sellers from cheating on their form filling?

4
0

Living with a Renault Twizy: Pah! Bring out the HOVERCRAFT

Steve Todd
Silver badge
Stop

Re: Consumption Is Consumption No Matter What You Are Consuming

Oddly enough there is a market for 5 seater executive saloon cars in that price bracket. Not everyone wants or buys the cheapest available model of everything. Compared to the cars it is designed to compete with (Mercedies S class and BMW 7 series for example) it compares favourably.

Tesla's plan is and always has been to start at the top of the market (where the margins are high) and work downwards. Their next model is targeted to cost $35k which is much more in the mainstream price bracket.

1
0

Tesla bumps up Model S P85D acceleration – with software update

Steve Todd
Silver badge

Back in the dim and distant past

When I was at 6th form the local Poly had a Univac 1110, which they paid a not insubstantial sum to upgrade the performance of. The engineer turned up to discover that someone had already moved the jumper and it wouldn't go any faster.

4
0
Steve Todd
Silver badge

Re: @Wyrdness

Given 80KG adults, that's only about an extra 0.3 seconds to 60 (it's a heavy car at over 2,200KG empty weight). It's screamingly quick for a car its size.

2
0

FORCE Apple to support BlackBerry hardware, demands John Chen

Steve Todd
Silver badge
Stop

Erm, wrong

Net neutrality is nothing to do with terminals or client systems, it is about the flow of data over the web (and how no ISP should throttle or impede trafic based on failure of the provider to pay a premium).

You can't use it as a stick to force Netfix et al to write software for your crappy platform, but you can use it against your ISP if there IS a Netfix app and they throttle it while pushing their own streaming video service.

19
3

Virgin, Qualcomm, back 600-satellite space internet plan

Steve Todd
Silver badge

Re: Latency?

That's because existing satellites are in geostationary orbit, much higher up at about 22,000 miles. A ping therefore requires a round trip of at least 88,000 miles (up to the bird, down to the ground station, to the server, back to the ground station, up to the bird and back to the sender), or about 1/2 second latency at the speed of light. This is reduced to a minimum of 3000 miles (of about 16ms) with this system

2
0
Steve Todd
Silver badge

$2bn in launch costs

Assumes $10,800 per pound to launch, which isn't unreasonable. SpaceX are aiming to get costs below $1000 per pound, so my guess is that they will get most of the work launching clusters of satellites at a time.

0
0

Apple v Ericsson: Yet ANOTHER patent war bubbles over

Steve Todd
Silver badge
Stop

Re: Strange how fruity patents are so valuable

Still not grasped the difference between FRAND and normal patents then? If a company wants to get one or more of their patents included in a standard then they must commit to licensing them under FRAND terms (Fair, Reasonable And Non-Discriminatory). If they do this then the fee per use they can charge tends to go down, but the number of items using it goes up so they can make good money from the licensing.

Ordinary patents carry no requirement to license and no fee structure. A company doesn't have to license them, and can charge whatever they can get away with if they do. Apple didn't want to license out its patents in the cases you've heard about, hence they were asking for more in infringement costs. They do however take part in a number of other patent pools (like h264) where they have contributed and get paid on FRAND terms.

Typically the Apple patent arguments have been over whether the patent owner can charge their fee on the radio element of the design, or on the whole RRP of the phone. Most companies get their licenses for GSM/LTE from the baseband chip manufacture included in the price of the chip, i.e. a few bucks per phone in total.

5
3

Tesla S P85+: Smiling all the way to the next charging point

Steve Todd
Silver badge

Re: electricty is so clean right

1) Most countries use a mix of nuclear, conventional and renewables. The cleaner the mix the cleaner the electric car is.

2) Improving the mix makes any existing electric car better. Petrol/Diesel engines never improve other than by replacing the vehicle.

3) EVs are a great way of soaking up surplus power from renewables when they are on stream, you store the energy in the battery, and many EVs make for large scale.

4) The pollution happens at the power station, which can be out in the countryside, rather than in the middle of a city, where it is bad for the health of those living/working there. Its also easier to clean up emissions in a large scale fixed plant than in the exhausts of thousands of mobile IC units.

1
0
Steve Todd
Silver badge
Stop

Re: It didn't change my mind

Take a look at the following review from Norway. A US spec Model S (no cold weather mods) driving 270KM in the snow, fully loaded, while climbing 800M on the way and not driven gently, managed it without a recharge. I'm not saying that there is no effect on range, but it has been rather over stated.

https://www.youtube.com/watch?v=XZ5PqPeOPT0

1
0

Forums