All About Symbian - Symbian, Nokia and S60 unwrapped.
Resistive vs Capacitive: Moving the goalposts?
Published by Steve Litchfield at 16:13 UTC, July 12th 2010
Summary:
In an article written some 15 months ago, just after the first S60 5th Edition smartphone had appeared (the Nokia 5800), I went in depth into the pros and cons of resistive versus capacitive touchscreens, pronouncing both technologies as being valid for different use cases. We're now mid 2010 and it's clear that capacitive technology is winning out, for mid and high priced smartphones at least. So what's changed? Who moved the goalposts? I try to explain below!
Before I comment though, just to summarise the pros and cons of resistive and capacitive touch technology, from the previous article (don't bother to look this up, some things are now out of date and I've amended this version of the table appropriately):
| Resistive touchscreen | Capacitive touchscreen | |
| Visibility indoors | Typically very good | Typically very good |
| Visibility in sunlight | Potentially only average, the extra layer reflects too much ambient light. | Potentially very good, but only if the manufacturer puts in a transflective layer (or, latterly, a Super AMOLED or IPS display) |
| Touch Sensitivity | Pressure is needed to make the contact within the screen's layers, can be affected with fingers (even with gloves on), fingernails, stylus, etc. The latter is important in Asian markets and anywhere where gesture or character recognition is important. | Even the slightest contact of your electron-rich finger with the screen's glass is enough to activate the capacitive sensing system below. Doesn't work with inanimate objects/fingernails/gloved fingers. |
| Accuracy | Accurate to at roughly display pixel resolution, as can be seen when drawing (or writing characters) with a stylus. Useful for handwriting recognition and interfaces with smaller control elements. | Accurate to within a few pixels, in theory, but seriously limited by the physical size of your fingertips, plus the low capacitive resolution of many devices, both of which make it hard to accurately press any control element or select something on screen that's small. |
| Cost | Cheap to use in a phone design. | Definitely more expensive than resistive screens, by between 10% and 50%, depending on who you talk to. On a flagship device, the extra build cost isn't that important, for a budget phone, using a capacitive screen might be prohibitive. (We've seen budget Android smartphones, for example, come with resistive touch) |
| Possibility for multi-touch | None, without re-engineering the way a resistive screen is wired into a device's electronics. | Depends on implementation and software, but used in the iPhones and on many (though not all) Android smartphones. |
| Robustness |
The very nature of resistive screens means that their top layer is soft, soft enough to press down and indent. This makes such a screen vulnerable to scratches and other minor damage. A resistive screen also gradually wears out and requires more frequent calibration. On the plus side, a resistive layer over a plastic screen does make for a device that's generally robust and unlikely to be damaged by a fall. |
Glass is usually used as the outer layer. Although not invulnerable (and certainly prone to shattering on major impact), glass is more resistant to casual scratches and blemishes, especially when 'toughened' (e.g. 'Gorilla Glass')... |
| Hygiene | Because a stylus or fingernail can be used to effect each touch, there's a potential for less fingerprints, finger grease and germs to be transferred to the screen. | Full finger touch is needed on the screen, though the use of glass as the main material means that the screen's also very quick and easy to clean. |
| Environmental concerns | Will work happily between -15°C and +55°C and at all real world humidities. | Typical operating temperature is 0° to 35°, requires at least 5% humidity (for capacitive effect to work), uncomfortable to use at high humidities. |
Looking at the raw table (slightly updated from the original article), it's clear that, in theory, my original conclusion should still stand. In truth, there are just as many (if not more) pros for resistive touch technology than for capacitive. However, use in real world devices rather belies this and for good reason.
Looking at the tech objectively doesn't take into account the software that these smartphones use, meaning the user interface elements. If all that was required was the odd tap of a menu option or a hyperlink, if just the odd 'OK' button and virtual keyboard tap was needed, then yes, resistive would win out for almost all devices. After all, they're cheaper, more adaptable, more robust, more accurate, and so on.
However, smartphone user interfaces have evolved. In contrast to the S60-with-touch added on approach, which fits in with the paragraph above and you can absolutely see why Nokia chose resistive screens for the N97, N97 mini, 5800, 5530 and others, we've had the iPhone OS and now Android, both heavily investing in the idea of swiping, dragging, pinching, splaying, pulling up, pulling down, gestures that make intensive use of movement along the touchscreen, not just tapping it to register a particular coordinate.
Whole application interfaces are now built around such 'intuitive' gestures and, with the best will in the world, trying to drag your finger across a resistive touchscreen while maintaining the appropriate pressure is, relatively speaking, hard work. When critics of, for example, the Nokia N97 and N97 mini refer to a user experience that's unexciting, it's usually that where the touchscreens are involved, they're distinctly underused, for the reasons just mentioned. In contrast, the iPhone and top end Android phones have more swiping and pinching than you can handle, with interfaces that respond to these sweeping gestures.
Nokia did add kinetic scrolling to most of their lists and panes, adding a degree of responsiveness to touch, but the issue of swiping with added pressure still seemed a little behind the capacitive competition. The Nokia X6 was the first mainstream Symbian smartphone to try out a capacitive touchscreen (the Samsung i8910 HD was, of course, the very first) and this did improve things slightly, but, as detailed in several editorials on All About Symbian over the last few weeks, if you're going down the touch route for a user interface then what's needed are the overhauls in Symbian^3 (to a lesser extent) and Symbian^4 (which should look dramatically different).
The upcoming N8 has a capacitive screen as well and, with the removal of any 'double-tap' confusion, should see a far better user experience (see the video demo embedded below), and I'd expect other Symbian^3 devices, announced over the next few months, to also use capacitive technology.
And so the goalposts have moved. What was once a case of detecting taps (think Psion Series 5, Palm OS, Windows Mobile and yes, even S60 5th Edition) is now part of a holistic user experience, where the fingertips rarely stop moving and where flesh needs to glide over ice-rink-smooth glass, caressing the hardware and effecting silky smooth changes in the interface beneath.
Such a sea-change, despite the objective pros/cons, means that for touchscreen smartphones in every tier but the lowest, capacitive technology is now mandatory.
Steve Litchfield, All About Symbian, 12 July 2010
Discussion
I work with a lot of dirt and dust, which has a bad effect on physical keypads, so I need touch.
I am 90% gloved so can't use capacitive.
I need something that is resistant to impact so I can't use capacitive.
So, I end up with a 5800 with tape over the three buttons. Works good!
http://zerolinesofcode.wordpress.com...acitive-touch/
Sounds like you need something ruggedised rather than expecting a consumer device to do the job for you
@bluejacker
Double-tap is supported on capactive as well. The best of both worlds!
The reason most people would not know the difference is that most people have not actually used touch screens at all (or have used only resistive ones). I own both an iPhone 3GS and an N900 and I can tell you the difference in user experience between the screen types is huge.
It's quite hard to explain. Even though the screen on N900 is very sensitive, you still need to apply some pressure, however minimal it needs to be. When using a capacitive screen you don't need to use *any* pressure at all. This yields a far better user experience.
And that difference is what makes capacitive screens become the dominant ones (at least in high end models) even though on paper resistive screens have better properties.
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Originally Posted by malerocks
Is it true about Capacitive screens working only in temperatures of 0 degrees to 35 degrees C? If that is the case, during winters in all places where it snows, people will not be able to use their devices at all?
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IceB
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Originally Posted by bp101
@Unregistered
Sounds like you need something ruggedised rather than expecting a consumer device to do the job for you ! |
The 5800 does it. already.
On the other hand, if you need or want a stylus (yes, there are some of us left), then resistive is the way to go.
So much for rational discussion. I think it's quite obvious who was the main pusher for the capacitive screens, and the US tech media followed suit.
Writing and Doodling.
Not the act of artistic authorship, the actual mechanical methodology of putting implement to paper and recording thought.
Especially true for artsy-fartsy/creative types, using tools specifically designed to create a semi permanent record is not something easily overcome with sweeping gestures on a 3" - 4"+ canvas.
Cross and other companies came out with pad sized digitizer solutions that allowed a user to write up notes on paper while recording them digitally with additional functionality provided by key input locations and gestures on and around the paper. Integrated OCR coupled with PC I/O planner style formats made these solutions intuitive and logical follow-ups for PDA's.
And then ..... crickets.
Instead, phones, PDA's, laptops and the ubiquitous paper tablet/planner became standard luggage that would show up on table tops during meetings.
One of the most elegant solutions that ever came about was a Papermate PHD Multi pen, a short stack of small, clear tab Post-Its, the ubiquitous tablet/planner portfolio and a PDA phone.
By the late 90's most PDA displays were large enough for the clear tab Post-Its which carried over to the PDA phones.
Stick a few Post-Its on the display and you'd have a semi-clear screen protector you could write on or just pull off for any reason.
Call up the handwritten notes or Post-Its like app, write your note, apply or give over the Post-Its and ShaZam! Permanent record, handy note/instant art, digital record and your screen is always in great shape.
Plus, Post-Its art rocks.
Has anyone tried using a Post-Its like app on capacitive screens with fingers? Very unsatisfying.
And newer resistive display technology is very very good.
http://www.youtube.com/watch?v=K7-OBoDFeDY
unlike the capacitive screen, resistant screen is vulnerable to scratches but will not break as easily as glass! (remember the N97 drop test?)
http://www.youtube.com/watch?v=MXGPc70pZQ4
On a mobile phone this could be used for a totally new interface. An example:
Tapping the display softly, sets focus to the element, dragging afterwards, marks a range.
Pressing (normally) selects (executes) the element (like double tap on S60 5th).
Pressing hard, pops up the context menu.
Of course you could use it for an extraordinary drawing app. Pressing hard makes thick lines, soft thin lines, ...
I think a pressure sensitive resistive display would be much more usefull than a capacitive display.
That said I'm sure my next handset, symbian or otherwise, will have a large capacitive touchscreen, which after a few days useage will become familiar and I won't even give the way it works a second thought, and as I live in the UK ambient temperature and humidity are unlikely to be an issue and so as long as it does what it's supposed to I'm sure I'll be happy with it :cool:
Its just some in the "have not" camps either didn't or want to see the goal post.
I have on occasion tried out a friend's iPhone with a capacitive touch screen. I found that dragging objects with my finger tip was so easy. Also, I didn't have to apply much pressure in order to register a press.
After reading this and the previous article on touch screens, I began to understand why various touch screens on various devices work the way they do. I played in a poker tournament where we used a table that was a large touch screen. I was told to use my access card (instead of my finger) to press on the buttons on the touch screen. Using my finger doesn't work. I guess it was a resistive touch screen.
I am pretty much used to my resistive touch screen on my N97. It is probably more to do with familiarity with the device than anything else. A friend who had an iPhone tried out my N97 and didn't like the fact that he had to apply some pressure when pressing on the N97's screen.
As for multitouch, the pinch zooming feature is probably the coolest feature available on a touchscreen device. The coolness of this feature is likely making manufacturers move to capacitive touchscreens. I have seen a pinch zooming feature work on a resistive touchscreen. The limitation is that you have to keep one finger in place while moving the other finger closer or farther away. On a capacitive touch screen, you can move both fingers when pinch zooming.
But the one thing you can do with multitouch zooming is to precisely zoom the way you want and this is something a slider is not fine enough to do.
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Originally Posted by Unregistered
Its not like u can't double tab to zoom in on phones with capacitive screens.
But the one thing you can do with multitouch zooming is to precisely zoom the way you want and this is something a slider is not fine enough to do. |
On the N900, Nokia have implemented spiral zoom, one handed, intuitive, accurate and able to select any level of zoom you want. Much much better and more practical, especially one handed.
Can't use gloves with Capacitive displays!
Hmmm http://i.engadget.com/2009/02/16/han...iphone-gloves/
Need a stylus so resistive is the only way!
Hmmm http://www.google.co.uk/m/products?o...w&ved=0CA4QywM
So, we can use gloves AND a stylus with a capacitive screen? No way! Technology these days....
Also regarding double tapping to zoom in, yes you can do that on a capacitive screen but can also pinch to zoom, I thought options were good? Hearing some of you folks it seems we shouldn't have innovative styles of zooming in, just stay with the old, seriously non impressive, double tap to zoom.....
I think the Market and user have switched to Capacitive, but YOU'RE not ready, change with the times man, you must be getting too old for this :-p
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Originally Posted by iFanboy
Thing is, Steve, is stylii and capacitive gloves have existed pretty much since capaictive screens first came out, yet you STILL badger on about them being a pro for Resistive screens.
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As for the stylus, my resistive screen phone doesn't come with a stylus, but I can just grab any (retracted) pen and use it as a stylus. I use a stylus on occasion and would be turned off if I had to spend $10-$20 on a specialised one.
The thing is, a majority of people can't even differentiate between capacitative and resistive but they sure can between single touch and multi touch. Since there are no phones available with resistive multitouch, they think its inferior.
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Originally Posted by iFanboy
So the arguments for resistive against Capacitive are:
Can't use gloves with Capacitive displays! Hmmm http://i.engadget.com/2009/02/16/han...iphone-gloves/ Need a stylus so resistive is the only way! Hmmm http://www.google.co.uk/m/products?o...w&ved=0CA4QywM So, we can use gloves AND a stylus with a capacitive screen? No way! Technology these days.... Also regarding double tapping to zoom in, yes you can do that on a capacitive screen but can also pinch to zoom, I thought options were good? Hearing some of you folks it seems we shouldn't have innovative styles of zooming in, just stay with the old, seriously non impressive, double tap to zoom..... |
Those gloves are absolutely no use to me and the ultimate in geekdom.
The stylus wouldn't have the fine line ability that resistive screens have, because it's a limitation of the screen sensor not the pointing device.
It's been pointed out and ignored by you that the one handed multi-touch is not great, and that Nokia have bettered this with spiral on the N900.
The temperature thing is not an anecdotal phone breaks in hot weather thing, it's laid down in the written specifications and conditions of use for the phone, specifications written by Apple. Not only that, but it's cold weather that forces gloves onto people.
You are not a fanboy, you are a hateboy. And not very good at this debating thing either.
