With the advent of summer in the Northern Hemisphere, Steve Litchfield reprises an old rant with a look at how the current crop of 2008/2009 smartphones fare on a sunny day. Does your phone turn into a hand mirror or can you see what's going on?

As with certain other subjects (which I won't go into here!) in the phone world, screen contrast on a sunny day is one I keep going back to - and for which I make no apologies. Almost every phone or PDA screen looks gorgeous indoors, but the acid test comes when you venture out into the big, bad world, with the sun's incandescence threatening to overpower the feeble screen backlight in your handheld device.

Now, you're unlikely to be checking your email or editing a document in the full sun (unless you're a real workaholic!), but you are likely to want to see the screen to:

• see who's calling you
• see the image of the thing you're trying to photograph
• see a map of where you are and where to go next

And so on. Over and over again, I believe that some manufacturers neglect to think about screen contrast in all conditions, with resulting poor choices in terms of technology and materials. What follows is just a brief sample of direct sun performance of some of the phones I happen to have to hand. If you're the really mobile sort, next time you're looking for a phone or smartphone, don't you think you should take the screen tech into account?

Device	In sunlight	Comments
Nokia E75 Uses a non-touch, transflective LCD screen, similar to those on the majority of (but not all) Nokia smartphones, including the E61, E71, N95, N82 and many others. Curiously, the N76 and N93i didn't use this screen tech and failed miserably in the market. Coincidence?(!)		Superb contrast in direct sunlight, since the sun's own light is bounced back past the LCD crystals from the reflective layer.
Nokia N96		Uses a tweaked, high reflectivity transflective screen. Stunning visibility in the sun, to be honest (and rather hard to photograph!) - Nokia's best ever screen?
Nokia 5800 XpressMusic Also some modern Windows Mobile phones (e.g. HTC Touch Diamond 2)		Not the worst TFT (with resistive touch) touchscreen I've ever used, but performance is poor in direct sunlight, since the backlight is directly competing with the sun.
Nokia N97	{Image under replacement}	A surprisingly good take on modern touchscreens, the N97 has a resistive top layer but on top of a transflective backing. The resistive layer dulls brightness slightly indoors and adds reflectivity outdoors in sunlight, but the result is still very useable, unlike the 5800's screen above.
Nokia N86 8MP/N85 (also Samsung i8910 HD and i7110 - reports are that the i8910 HD is better, but I really don't see how this is possible. Watch this space!)		Nokia's first AMOLED screens. Utterly gorgeous inside and just about readable in sunlight (OLED much brighter than TFT) as long as the sun's not directly behind you (as was the case here, give or take a few degrees) - in such a case, the screen simply blacks out, since the OLEDs can't compete.
Samsung INNOV8  (also the rather forgotten G810 (the camera-centric one with Xenon and optical zoom)		Appalling use of TFT for a traditional phone form factor. Not only that, but it's a terrible TFT and the screen is effectively invisible whenever the sun's out. A showstopper, I'm afraid.
Apple iPhone/iPod Touch (also the T-Mobile G1 and other HTC Android phones, plus the Palm Pre)		Uses a transflective LCD, like most non-touch Nokias, but cunningly adds a capacitive touchscreen that doesn't get in the way of light. Visibility in the sun is almost as good as on the likes of the N95 and E61.
HTC TyTN 2 (and all previous Windows Mobile phones)		This is resistive touch, TFT, and the combination of the extra resistive touch layer and the transmissive technology mean that visibility is very poor in the sun. Marginally worse than the Nokia 5800, I'd say.

Steve Litchfield, All About Symbian, 24th June 2009 (minor update Sept 09)