HTC diary - London Launch Event 2014 by Tom

25.03.2014 - The All New HTC One

It was damp and cold when I got to the station; a 20 minute walk in the drizzle. I didn't care - the excitement I was feeling was a bit silly really - I felt a bit like a Belieber going to their first concert. Where I was actually going was to The Olympia conference centre in Kensington to see the HTC One M8 unveiled. I was one of only 20 HTC Elevate Members chosen to attend this event, so I was feeling privileged, excited, apprehensive about meeting new people, and also not looking forward to the length of the day. The train arrived on time, and I headed to the Parcel Yard pub at Kings Cross - where I met up with most of the other Elevators who were going to the Event. We then got on the Underground and went to the venue; where we were pretty much fast-tracked through a registration process and led to seats at the front of the auditorium.

This was a much bigger venue than last year; massive black cloth drapes and moody lighting were accentuated by a thin fog of fake smoke. As we entered the main room there were a good few hundred seats all full of reporters, VIPs and other guests, and of course Laura Kimball with her trusty intern sidekick Britt. We had seats on the very front row, right by the stage. Kevin, Dan, and myself got logged in on our phones and connected to the Hangout that Mike was hosting, and started filming straight away. There was quite a wait until it started but once it did, Phil Blair, HTC's EMEA President, introduced the show and what HTC were thinking about when they designed this year's phone; and then brought on Cher Wang who clearly showed her passion for great devices and great user experiences. Once she had wowed us, she brought on Scott Croyle, HTC's design guru, to tell us about the phone itself, and all its new features.

All this was interspersed with loud music and great graphics on the huge screen behind the stage. The whole atmosphere was one of excitement, and joy, and passion - showing just why HTC make such great devices for the user, whether they be casual users or massive tech geeks.

Key points that I took away about the phone are the massively improved camera which even allows setting apertures and shutter speeds; new features enabled by the second rear camera such as refocussing after the photo is taken; improved boomsound performance; and lots of little doo-daddy bits to make the user experience even better than Sense 5.5 was.

After the main presentation, suddenly the drapes at the side of the main hall were pulled away, revealing an area as big again as the hall, but filled with benches containing  dozens and dozens of demonstration phones. Some were simply set up so you could play with the phone itself, whereas some benches were set up specifically to showcase specific features - one for the camera had models standing and posing for people to use the cameras on; the ones for HTC TV demos had actual televisions lined up in front of them etc. All the time, staff were approaching us with Canapes and drinks. There were more than enough demo phones to go around, the event seemed to have been very slickly organised. Towards the end we saw staff wandering around with signs to assist journos wanting buses to airports and so on.

After the event, we all gathered and walked to a Byron's Burger bar about 15 minutes' walk away, where HTC treated us to burgers and beers for a good few hours. We spent all of this time laughing, joking and discussing the new stuff we'd seen; this to all of us is an extremely exciting device. It looks fantastic in the hand, it's slick, fast and easy to use, and the features under the facade are absolutely brilliant. If you have even half a chance of buying one, do it - you will not be disappointed.

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Lithium-Sulfur battery cells, the upcoming replacement for Lithium-Ion

Lithium-ion batteries, the current battery technology used in smartphones, has a high specific energy (energy per weight) but has a few drawbacks. Let's take a closer look and compare both technologies.

The main issue with Li-ion is that is requires lithium dissolved in extremely volatile and flammable organic solvents; e.g. dimethoxyethane which has a low flash point -2 °C (28 °F), the temperature at which a volatile substance can evaporate and form an ignitable mixture in air. This makes them extremely dangerous when the charging circuits malfunction and fail to protect the battery from overcharging, and consequently overheating. We have seen some scary stories in the recent past with people waking up to their phone bursting into flames while they were charging overnight, and the battery fires in the new Boeing 787 Li-ion battery packs. So obviously there is need for development into a safer battery composition with similar or better energy capacities.

Recently I did some research into the developing Lithium-Sulfur battery, with extremely promising specifications at the present time better than Li-ion. Li-S is extremely light weight due to the use of sulfur instead of ionic liquids, additionally sulfur is much cheaper to produce than ionic liquids. Despite frequent headlines about new battery compositions with potentially high capacities, Li-S is actually in the production stages and no longer just a concept.  

The chemistry behind Li-S is essentially the lithium gets plated onto the anode when charging and poly-sulfides are reduced and coat the anode when discharging, compared to the use of intercalated anode and cathode plates in Li-ion. This is the main factor which gives Li-S potential to be a battery composition with an extremely high specific energy. The different chemistry also allows the use of much less volatile solvents such as polyethylene glycols (flash point up to 287 °C/548 °F).

The degradation of Li-S is different to Li-ion but is also susceptible to an increased rate of degradation at high temperatures. There are unwanted side reactions that can take place, but are reversible until they dissolve into the solvent. Luckily sulfide compounds are relatively insoluble in electrolyte solutions but any increase in temperature will increase their solubility, so batteries need to be well regulated to prevent rapid charging and discharging.

Manufacturers are beginning to pour money into research and development for Li-S as there are a lot of factors which can be significantly improved, from something as simple milling smaller sulfur and carbon particles to something more difficult like developing a better solvent to improve battery capacity and reduce degradation. (Carbon nanotubes/nanofibres are used as a conductor due to sulfur’s poor electroconductivity, and they are still quite expensive to produce.)

I've put a graph at the top to compare rechargeable battery technology in the past with Li-S. Now, time to see which OEM will be implementing Li-S first.

TL;DR Lithium-Sulfur batteries are capable of having a higher wattage per weight than Lithium-ion whilst being both safer to the consumer and cheaper to manufacture.

Puncture test comparison

Short circuit test comparison

This article is also to be found on its author's personal blog.

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What’s new in 2014 - a year of technology

What’s new in 2014...

Have we reached the point of diminishing returns?

With 2013 now behind us, I want to look back upon the past year and analyse the technology we saw, as well as speculate upon what we are likely to see this year. I think 2013 was a relatively disappointing year for mobile phones, however 2014 looks more promising.

Displays of 2013

For many, 2013 will be known as ‘the year of 1080p screens’, as almost every flagship model incorporated these high resolution displays at the cost of battery life and overall fluidity. This meant that overall performance seemed stagnated in general operations, with the HTC One X rarely under performing to the HTC One, except in gaming performance. 

However, the benefits of a 1080p screen as compared to a lower resolution are noticeable to most and definitely offer an improved experience, resulting in less eyestrain and the ability to browse the web more elegantly. Of course, not every 1080p screen is equal. We saw improvements in colour reproduction, brightness and touch sensitivity in 2013, as well as advancements in technologies like AMOLED. With Apple retaining it’s sub-720p display on the iPhone 5S, many agreed that this was subpar and that this will need to be improved upon in 2014, else market share will suffer. The Xperia Z was widely criticised for its poor viewing angles, resulting in poor sales despite otherwise quality hardware. This shows the great importance of a quality screen in the current market. Display size in 2013 saw a huge increase from previous years. In 2010 for instance, the display of the iPhone 4 at 3.5 inches was considered large. By 2011, the Galaxy S2 had upped this to a 4.2” screen, and in 2012 the Galaxy S3 was released with an even larger 4.8” screen. 2013 can be known as the ‘phablet year’, with a large number of phones released with a screen size larger than 5 inches. This is a trend on the rise and I believe that in 2014, any screen with a size less than 5” will be regarded as ‘small’.

Displays of 2014

In 2014, many smartphones are rumoured to be incorporating WQHD screens, with a resolution of 2560 x 1440. This is a resolution higher than most laptops on the market and seems to be overkill for a screen so small. The benefits of 1080p were visible, but with another resolution jump, the impacts on performance and battery life don't seem justified. A 1080p screen seems pin sharp and any higher may truly be more pixels than the eye can distinguish. This year in the television industry, there will be a major focus on OLED displays, due to their superior black levels, brighter whites and fast refresh rates. However, in the mobile industry I believe that LCD will still dominate, due to a cheaper cost and advancing technologies allowing for higher resolutions on a thinner screen. Only Samsung and Nokia are currently utilising OLED screens and while they are praised for their colour saturation and black levels, many argue that the colour is not reproduced accurately and that the Pentile matrix of Samsung’s latest screens means that they are not at true 1080p. OLED displays also commonly have a tint, resulting in darker, less pure whites. The S4 for instance has a clear blue/green tint when compared to the HTC One which uses an LCD. To conclude, I believe that in 2014, 1080p will be the standard resolution for most phones, with a few rising to 2560 x 1440. The benefits of this are yet to be determined. Screen sizes in 2014 will be 5” or above for flagship devices, with the Galaxy Note series increasing to around 5.9”.

Batteries of 2013

In any portable device, battery life is a major concern and in mobile phones, this has an even greater importance. Over the past few years, battery life hasn't really improved. This isn't due to the non advancement of battery technology, but more due to the increased power usage of components in phones, with the latest screens and SoCs using more power than they did a couple of years ago. This creates the illusion that the batteries used are exactly the same as those used in 2011, while really they are advancing at a steady pace. For example, the HTC Desire (was one of the highest rated phones of 2010) utilised a 1400 MaH battery, while the HTC One uses a 2300 MaH battery. With 900 MaH extra capacity, the HTC One should have greatly improved battery life, while in reality it is not much different. This is because of the more power hungry components. One anomaly in 2013 was the iPhone 5S, which uses a 1570 MaH battery. This is far lower than other flagship phones on the market yet still manages to provide a days usage. This is due to the less demanding processor, as well as software optimisation in the closed Apple ecosystem. The drawback of current batteries is that they are still too large. To include a large 3,200 MaH battery such as the one found in the Galaxy Note 3 requires… you guessed it, a phone the size of a Galaxy Note 3. This means that phones cannot continue to get much thinner with the current generation of batteries, else battery life will suffer. 

Batteries of 2014

Phones released in 2014 will have a healthy bump in MaH as compared to 2013, however we shouldn't expect to see a noticeable difference in usage times, due to the impending release of WQHD displays and even beefier processors. I believe MaH will hover around the 3000 MaH range for flagships this year, with phablets potentially pushing towards the 4000 MaH mark. A day of solid usage can be expected. One thing that split opinions in 2013 was the issue of the removable battery. It was argued that it was required in order to switch batteries when the original had lost charge through age and that non-inclusion was a type of planned obsolescence. Others argued that many don’t keep a phone for longer than 2 years and that in this time, a battery would still maintain at least 75% of the original charge. Personally, I find a removable battery useless for my needs and think that the design changes required to incorporate one are detrimental to the looks of the phone. I would take a well built solid unibody phone over one with a removable flimsy back cover any-day. In fact, a removable battery just seems so old school, Nokia 3310 anyone? In 2014, unibody phones will be standard.

Cameras of 2013

In 2013, DSLR sales suffered. This was mainly due to the increasingly good picture quality on mobile phones. While professional photographers can’t sell their professional equipment yet, for many users a mobile phone camera is more than sufficient. Cameras in 2013 saw resolutions as high as 13 megapixels, while some manufacturers decided to go in the other direction: reducing the number pixels in return for better low light photos and less noise. There is split opinion on the effectiveness of this strategy. Personally I prefer the photos taken from the standard 8 megapixel HTC One X camera than those taken from a 4 megapixel HTC One, with 2um pixels (‘Ultrapixels’). The 13 megapixel camera of the Galaxy S4 can take some great shots, however colours are too processed and noise is an issue with such a small sensor. Overall, I think that the greatest camera of 2013 was that on the iPhone 5S, which features an 8 megapixel shooter with larger pixels like seen on the HTC One. This allows for good sharpness while also reducing noise. Mobile phone cameras now have a number of quality features that even DSLRs can’t match, such as high quality slow motion video, 4K video recording and options to remove unwanted objects from an image with a simple tap. Shooting speeds also dramatically increased from 2012, with speeds of up to 10 photos per second. 

Cameras of 2014

I think that this larger pixel technology will be seen more often in 2014, with HTC and Apple likely to continue the trend. However, I wouldn’t expect to see Samsung attempt this. In fact, a 16 megapixel camera on the Galaxy S5 wouldn't surprise me. HTC will likely release an 8 megapixel ultrapixel camera, while Apple could either remain at 8 megapixel or jump to 13. Expect to see an improvement in editing options this year, as well as the rise of 4K video. Optical image stabilisation will also be included in most of the flagship devices, as this removes camera shake from photos, meaning that photos taken with a non steady hand or on the move won’t be blurred.

An 8MP camera with 2um pixels will require a phone to be 18mm thick at the camera site; not sure if any manufacturer will go there. Check out this article for more details - Cameras in Phones - what do we really need?

Processors of 2013

Qualcomm dominated 2013 with their Snapdragon range. In fact, every Android flagship of 2013 used a variant of a Snapdragon processor, with the exception of the 8-Core Exynos processor used in certain non-European models of the Galaxy S4. The first 64 bit mobile processor came in 2013 with the launch of the Apple A7. This offers certain improvements, such as a 25% performance increase just for apps that are compiled in 64bit, as well as being able to handle more RAM for the future. Processors have reached the stage where most activities on a device are fluid and apps launch very quickly. The GPU on a SoC matters more, as this determines gaming quality and can affect the FPS of general device navigation and scrolling. The Snapdragon 800 and Apple A7 are very fast CPUs. An interesting point is that while all Android flagships used a quad core CPU in 2013, Apple only used a dual core. The dual core A7 even outperforms the quad core Snapdragon 800. This is due to the ARMv8 internals of the chip. Every processor currently used in Android devices is ARMv7 or less. ARMv8 offers a number of improvements including 64 bit support, faster handling of encryption and an increased number of registers.

Processors of 2014

Currently, the Snapdragon 805 is expected to be released in the first quarter of 2014. This is known to have a maximum clock speed of 2.5GHz and an Adreno 420 GPU. However, it is still based on ARMv7, meaning it is 32 bit. This means that Qualcomm is actively slowing down the development of ARMv8, even with ARMv7 currently at the end of its cycle. I expect to see an ARMv8 processor from Qualcomm towards the end of 2014. Processors will remain at quad-core for the most part and I expect Apple to keep its dual core set up which has proven itself as a great performer.

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Merry Christmas everyone!

Android Revolution HD Team would like to wish you all Merry Christmas and a happy New Year 2014.

May love and happiness be a part of your everyday life. 

Forget about the problems and enjoy the moment. Smile, laugh and share the love.

Of course, we also wish you quick Android updates and a lot of flashing.

Android Revolution HD

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Sense 5 Toolbox - the best customizer for HTC Sense 5 based ROMs

If you haven't used it yet - you really should. I'm talking about the "Sense 5 Toolbox" application, made initially for Android Revolution HD. In the last few weeks the popularity of this application reached an unexpected level, and we believe it's a reason to celebrate.

More details about the Sense 5 Toolbox can be found on this blog, under "Sense 5 Toolbox" link on the right panel. Or, just click here.

Why Sense 5 Toolbox?

The application is an answer for 2 basic issues: many users wants to customize their OS as much as possible, but currently available solutions similar to Sense 5 Toolbox are very limited when it comes to the possibility of using them on most custom ROMs.

Android Revolution HD is known to be a "stock-looking" ROM, which was always the most important aspect for many users, who were looking for a stable and well known custom ROM. However, having a custom ROM with such popularity brought our attention to many users, who were looking for a stable custom ROM, but also with a little touch of customisation features - like displaying the battery percentage, or being able to re-order or re-design some part of the UI. This leads to two different approaches:

1. having a custom ROM full of many more or less advanced features coded into the framework, which always ends up with all sort of issues, bugs, waiting a long time for a new ROM version based on freshly released official OS update etc; or
2. having a custom ROM like Android Revolution HD, close to stock with just a few changes under the hood to make Android users life easier, combined with a standalone application like Sense 5 Toolbox.

The result is what most users are looking for: stock looking by default, a stable and optimized custom ROM - but with the capability to change many things inside the OS.

With Android Revolution HD and Sense 5 Toolbox you have:

1. fast updates when a new OS is released/leaked,
2. a stable custom ROM,
3. the capability to customize your OS,
4. great performance because of the tweaks under the hood,
5. many features not available on the stock ROM.

The Sense 5 Toolbox is under continuous development. More and more features are coming with each new release and the "to do" list is quite large.

In the background, another project is still alive and under heavy development too. I'm referring to the "Revolution Toolbox" application, announced in this post few weeks ago. It's still being tested, however we are getting close to the first public beta. Just one little secret I can say out loud now - Revolution Toolbox and Sense 5 Toolbox will "connected" in a particular way. Can't say more for now, stay tuned!

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NFC vs. Bluetooth (and why Bluetooth is better)

NFC is by no means a new 2013 invention, despite what the recent influx in NFC enabled phones may lead you to believe.

History of NFC

In 1983, Radio Frequency Identification was patented. This the earliest form of NFC, and features in contactless credit cards. A drawback of RFID was that it did not support two-way communication, which makes it less secure than NFC. In 2003, NFC was approved as an ISO/IEC standard; in 2004 Nokia set up the NFC Forum (which can be found <here>). Designed to promote the uses of NFC and ensure that new devices were compliant, the website now has over 170 corporate members including mobile manufacturers, banks and mobile network providers.

Unveiled in 2007 at the Consumer Electronics Show in Las Vegas, the Nokia 6131 NFC was the worlds first fully integrated NFC mobile device. This led the way for more NFC enabled phones, with 100 million shipped in 2012. In 2013, this rose by 156% to a total of 400 million devices globally. It is estimated that by 2015, 53% of phones will be NFC-enabled.

History of Bluetooth

Bluetooth is an older technology than NFC as the name was adopted in 1998 - a full 5 years before NFC was approved. The Bluetooth SIG (Special Interest Group) was established in the same year to promote Bluetooth and gain corporate partners. The SIG was party to 400 members by the end of 1998, and by 2013 it has reached over 19,000 members, including high profile companies such as LG and Apple. The first mobile device to have Bluetooth was the Ericsson T36 in 2000, which allowed it to pair with the first headset which was also released that year. Now in 2013, over 20 million Bluetooth enabled devices are shipped per week, with the total number exceeding 2.5 billion. This means that Bluetooth is still much more widely used than NFC, although this gap is set to narrow substantially throughout the next 5 years. Bluetooth has gone through a number of advancements over the years and is currently at version 4.0, which is supported in Android 4.3. This is not new however, and has been around since the iPhone 4S. A detailed article on the inclusions of Bluetooth 4.0 will follow.

Security

In terms of security, both NFC and Bluetooth are fairly secure. Bluetooth has a range of 9.75 meters (or 32 feet), while NFC has a maximum range of 4cm. This means that NFC has the edge, due to the fact that a hacker would need to be right next to you for an attack to work, while Bluetooth has a longer working range. 

NFC doesn't come with built-in security measures, however the limited range offers great protection. NFC is also extremely sensitive to direction, and even a slight directional movement on the device will disrupt the signal. NFC is only active when it needs to be, meaning that even if you leave it on in your pocket, the NFC chip isn't actually functioning. This further increases security.

Unfortunately, NFC can be exploited in other ways. Take a smart tag in a magazine, programmed to open the webpage on your phone. A hacker can manipulate this and change the code to instead make it send premium text messages, costing you hundreds in a matter of minutes. The worst part of this is that you wouldn't even know until your monthly bill arrived. To avoid scams such as these, try to avoid using tags which aren't behind a barrier, as these are less easily accessible and harder to tamper with.

Another concern with NFC is privacy. When you pay for a product in-store, you are identified and your purchase information is stored. The shop then uses this information to send you advertisements based on products you may find desirable. The privacy concern is that shops can then sell this information to third parties, who may in return send unsolicited spam. 

Bluetooth implements an authentication mechanism based on the SAFER+ block cipher. This means that when two devices attempt to connect, they will both need to enter the same numeric PIN code for the transfer or connection to take place. This ensures that a malicious connection cannot take place without the victims knowledge and acceptance. Two devices can be 'paired' which means that they will no longer require entry of a code. This is useful for allowing a trusted device to connect easily, but can open security risks if a paired device is compromised.

Bluejacking is the process of sending a file to an unsuspecting victim, which is usually harmless (like rick rolling) but can occasionally be malicious such as the ability to take control of a device and call premium rate phonelines. A number of Bluetooth vulnerabilities have been found in its history, however most have since been patched. A major bug in 2007 meant that a hacker could open a remote root shell on any Mac running OS X 10.4. This shell could then modify the contents of the hard drive, and reveal sensitive documents. 

Ease of Use

NFC allows a fast and easy connection between two enabled devices. The lack of authentication makes a file transfer as simple as quick bump. While this opens a security hole, it means that NFC is very easy to use, and requires much less knowledge than Bluetooth. Once turned on, NFC will be automatically enabled when needed, and doesn't require any further setup. One advantage of this is that there is very minimal battery drain with NFC left on. Bluetooth can drain an excessive chunk of power even when powered off. Bluetooth requires the entry of a PIN code first, and has many settings to configure such as device name and pairings. This ultimately makes Bluetooth file transfer less intuitive than the simple bump needed with NFC, however it ensures that transfers are secure.

(Note: most file transfers initiated using NFC take place over Bluetooth - NFC has no capability to transfer data bigger than a few short instructions or a small amount such as a contact card).

Abilities

NFC transfers files at a maximum data transfer rate of 424 kbit/s, which is much slower than the theoretical 24 Mbit/s rate of Bluetooth 4.0. NFC is only suitable for small files, and Bluetooth shouldn't really be used for files over ~ 150mb. For large files, Wi-Fi Direct is recommended, which is a different matter entirely.

Bluetooth allows a connection to headsets and speakers: a feature which NFC doesn't support. This means that for people wishing to stream their music through their car speakers or headphones, Bluetooth is the only option. NFC simply lacks the range required and does not support audio streaming. Bluetooth is also used with smart watches, which display texts and other information directly on your wrist.

NFC can be used with tags. When the phone touches the tag it can activate a number of commands, which include opening an application on the phone, loading a webpage or even changing settings such as toggling Wi-Fi. This is useful as it means that 4G can be activated as you leave the house, and Wi-Fi can be turned back on when you enter, which can potentially save a lot of battery. In regards to battery life, NFC typically draws around 50mA of current when powered on. This is reduced by a couple of features baked into the Android OS: 

NFC polling is limited to 10Hz, meaning the transceiver will only looks for tags at certain intervals and not consistently, which helps battery life greatly. This polling is completely disabled when the screen is turned off, which means that when your device is in standby, so is NFC. When the screen is merely locked, polling ceases but card emulation doesn't, which allows apps such as Google wallet to function.

NFC will generally consume minimal amounts of battery, with the general consensus being around 0.5% a day with no use, which wouldn't be missed. Bluetooth drain is slightly more, perhaps around 4% per day, however this is also barely noticeable in real world use. 

Final words

In conclusion, I still feel that NFC has a long way to go before it will match Bluetooth, due to limited range and low file transfer speeds. It is easier to use than Bluetooth, however has limited use, only being useful for small file transfers. Bluetooth is great for streaming music to an external speaker, and for transferring files from a PC to Phone. Not many PCs have NFC, but all can be fitted with a Bluetooth dongle, and all Apple laptops have Bluetooth 4.0 inbuilt.

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Pixels and Pixellation

How many pixels do you need? This is a question many, many people ask and to be honest I think it's the wrong one. Let me give you a few numbers!

First of all, it's widely accepted that a monitor with more than 100 "dots per inch" or "pixels per inch" placed 18-24 inches from your face looks pretty good - with outstanding monitors at that distance having 130-170ppi. I'm also going to assume that the average monitor resolution is 1080p - that's 1920x1080 pixels in a 16:9 rectangle. This is actually quite generous but I've done that deliberately. Now when you're printing images on paper, it's generally accepted that 200ppi is "reasonably good" quality, and 300ppi is "excellent".

Full image - 2688x1520 (4 million pixels) displayed at 600 x 339

So - with a 4 million pixel image in a 16:9 arrangement, your image dimensions are going to be close to 2688x1520. If we divide that by 300ppi for printing we get a print size of 8.96" x 5.07". Call it 9" x 5" for round numbers and you're looking at an "Excellent" quality image bigger than most commercially bought prints which would be 6" x 4" or 7" x 5". Start blowing up from 9" x 5" and you're slowly going to start losing image quality. Pixellation will likely begin to occur at about 13" across. For displaying on a screen it's a completely different story: 1920 x 1080 pixels is about 2 million pixels altogether; and at the very best quality I've ever seen for myself (130ppi) that's a monitor size of 14.76" x 8.31" (about a 17" 16:9 monitor). So - if you display a 4 million pixel image on this monitor you're zoomed out so that half of the pixels in the image are never displayed. If you zoom in so that every pixel is displayed you can only see half of the image's area: but still at 130ppi you can't see individual pixels and the image quality is absolutely perfect. On my monitor at work, which is 22" 1680 x 1050 (90ppi) I begin to be able to resolve individual pixels with the naked eye when zoomed in to around 350% - where each image pixel is represented by 3.5 screen pixels on average.

So - let's use these as our ballpark figures; zoom in to 350% or print larger than 13" for individual pixels to appear on a 4 million pixel image.

The original image, cropped to 600 x 339 pixels and displayed at full size. Note the complete lack of pixellation - although there is a certain fuzziness to the detail.

Now, let's look at how the vast majority of mobile phone users use the photos they take. Please don't think of yourself or your friends here; think of the millions of people buying smartphones and how THEY use their pics. Look at Facebook, Flickr, Tumblr, Twitter, etc. That's right - MOST people - the vast majority - use the photos the way they come out. They don't edit, they don't crop, they don't zoom, they don't do any more than perhaps a bit of red-eye removal. And how are those images distributed in the main? They are very rarely displayed at their full size (in fact Facebook almost never even holds the pictures at full size but "processes" them in a way which removes massive amounts of detail and image quality to save storage space). Most places (Facebook included) allow you to choose a range of sizes to upload at, to optimise data traffic and storage space use.

The original image, cropped down to 198 x 146 pixels, and displayed at 600 x 339 to keep the playing field level with the other images. Note the fuzziness; and you can start to see individual pixels. This is now less than 9% of the original image, AND it's blown up to four times actual size.

So - the image you see on the screen is usually displayed to you at 600-1000 pixels across - far less than the original photo. At this resolution, a photo taken at 13 million pixels and a photo taken at 2 million pixels will look EXACTLY THE SAME. There is simply no way to see the original detail because making the picture that size has destroyed it - and if both are now the same width with the same scene depicted the remaining detail in the picture is also the same.

Now - there are a minority of smartphone camera users who shout "but I crop, zoom, edit my images - 4 million pixels is not enough!". I don't want to make fun of those people but - if you take a photograph so poorly that the image you want from the original picture is 30% or less of what you photographed, you're doing it wrongly. Take the photograph you want in the first place rather than taking a wider scene and then cropping it down to a postage stamp. Move closer to the subject and frame it properly. If you can't move close enough that the subject is easily visible in the frame, then a smartphone camera is the wrong tool for that image. Use a camera with a nice big lens, optical zoom and a nice big sensor. Smartphone cameras were (and are) intended for quick opportunist snaps; although a skilled photographer can capture some outstanding images with even a 4 million pixel smartphone camera because they're a skilled photographer. For examples of what I mean, look up Colby Brown who uses smartphone cameras to take many of his unbeatable images. All are displayed on his site at 1140 pixels across and yet they look absolutely fantastic regardless of the camera he used. Another up-and-coming digital photographer is Craig Fish who also uses a 4MP smartphone camera for many of his shots.

To prove my point, here are links to one image which has been progressively halved in size until the smallest one is HALF A MILLION PIXELS. I challenge you to see the loss of quality without zooming in... until you get below the resolution of your monitor.

Original image: 4 million pixels

Half Size – 2 million pixels

Quarter size: 1 million pixels

One eighth size: half a million pixels

This article is also to be found on its author personal blog.

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Cameras in Phones - what do we really need?

An awful lot is being said about mobile phone cameras just lately; and we have HTC to thank for opening the conversation with the introduction of their HTC One which has half as many pixels at twice the size of anyone else's. Before we begin I'm going to get some ground rules. I won't use marketing terms; so I will talk about how many pixels a camera sensor has, and what size they are. You won't hear me talking about mega- or ultra- anything. Next is that I will show my meaning with diagrams - I'm a visual person and it helps me to explain. Please bear with me on this post; there's a lot to read but it's worth it at the end.

A digital camera uses a lens to focus an image onto an oblong of special material which has a number of sensors on it; each sensor is called a pixel and usually contains three sub-pixels; a red, a blue (actually two blues but don't worry about that) and a green one. Each of these sends a signal to the camera depending how much light of that colour is falling onto it. Bigger pixels produce a bigger signal for the same amount of light than smaller ones. When signals are small, the amount of noise (erroneous signal levels produced simply by electrons moving around) is a bigger percentage of the whole signal because noise is a constant backdrop. When the signals are bigger therefore, it's easier to pick out the signal, from the noise. More noise means that the signal produced by a smaller pixel is less accurate which means the final photo may not have exactly the same colour from each pixel receiving the same light.

Camera sensors line up their pixels in rows and columns - and the camera's rating is often quoted by counting them. For instance a 10MP camera contains ten million pixels (roughly). These are arranged in a rectangular grid with a side length ratio of 16:9 - so that's 4213 pixels across and 2370 pixels high. If you have a sensor which is 7mm across, each pixel is 7/4213=1.662 microns across (microns = thousandths of a millimetre).

In the real world, standard sensor sizes and pixel sizes exist; a 13 million pixel camera in a phone will have pixels about 1.1 microns across; this gives a sensor width of about 4.55mm (there are 4128 pixels across the image). In the HTC One, the best photos are 2688 pixels across, and the pixels are 2 microns across giving a sensor width of about 5.4mm.

Figure 1 - 4 million large pixels

Figure 2 - 8 million (smaller) pixels on same size sensor

Now we can start looking at construction. Take a look at Figure 1. This shows a camera with large pixels - the lens is focussing the image onto an area exactly the same size as the sensor. In Figure 2, we gave the camera more pixels (which really does give more detail in the image but at the expense of noise and grain - and also less sensitivity at low light levels). Of course; straight away you want more, BIGGER pixels. Figure 3 shows that if you make that happen, the image doesn't cover the whole sensor; the light falls on a little bit of it. So - in Figure 4 we move the sensor further away to ensure the image covers all the pixels.

Figure 3 - 8 million large pixels with no other changes

Figure 4 - Sensor moved away, but the lens size is unchanged.

However; the same amount of light, entering the lens, is now spread over a wider area: this dims the light hitting each individual pixel, which reduces the signal output and increases the noise. The only way to change this is to make the lens bigger - the aperture wider - so that more light gets in. This is shown finally in Figure 5.

Figure 5 - all required changes incorporated.

So - how far back do we have to move the lens? Simple trig shows us the answer. Imagine the "field of view" of the lens is about 60° (not unreasonable): the light coming in from the left and right cross over in the centre of the lens and make a triangle with the sensor as the base... an equilateral triangle is formed with all angles at 60° and all sides the same length (let's call it 5.4mm to stick with the HTC One's sensor size). So the lens must be 2.7mm away from the sensor. If we now make the sensor an 8MP one (3800x2140 pixels) that gives a width of 7.6mm - the lens still has a viewing angle of 60° so that means the sensor has to be 3.8mm away from the lens. Obviously I have used 60° as the lens viewing angle because it makes the angles, sines and side lengths easy to calculate - the numbers are probably quite different in real life but you get the idea: to get double the megapixels you have to move the sensor further from the lens, which means you need a bigger lens to gather the light needed to adequately illuminate it. Lenses very rapidly increase in price with size - a lens 4mm across instead of 2mm might cost three or four times as much. (BTW - the large circular opening on the back of the phone is NOT the lens; the lens is the tiny dark speck in the centre of it).

In practical terms for a smartphone? This means that, to get an 8 million pixel camera, with pixels 2 microns across, your phone would need to be about 16-18mm thick (at least at the camera's location); and the phone would cost upwards of US$1000 - possibly even more - JUST because of the lens.

This isn't something which can be corrected with better design, or better lenses; the only way to mitigate this increase in size and cost would be to make smaller pixels which had the properties of larger ones - and that my friends is the nirvana of a pixel scientist! The very best technology available is going into these phones - and with today's tech we're stuck with these limitations. In another article I'll talk about why I believe 4MP at 2 microns across is enough.

This article is also to be found on its author personal blog.

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