Yesterday around Noon, iOS 4.1 became available to install on your iPhone, and there are a lot of new features for a mere .1 upgrade. Here is what you can look forward to with the latest version of the iPhone operating system.
HDR Photos. If you have an iPhone 4, you can ow turn on HDR mode when you are taking a photograph to tell your iPhone to take three pictures in a row with three different exposures and then automatically combine them to create a high dynamic range photograph in which you see more even more details in the photograph. In the settings for the Camera app, you can elect to keep the original photo without HDR enhancement in addition to the HDR photo. Taking an HDR photo adds a few additional seconds of processing time, but when you have vastly different lighting situations such as a person or object in the foreground and a bright sky in the background, you can get much better pictures with the HDR mode turned on. HDR can help you to bring out details in dark areas, such as the bricks and the flowers in the following picture, with minimal sacrifice to the bright areas (HDR photo on the right):
HDR really shines when you want to focus on an object that is indoor while also being able to see what is out of a window on a sunny day, such as this picture where I tapped on the plant in my office to make it the focus, but with HDR you can also see the Mississippi River Bridge out of the window of my office:
(You can click on any of those pictures to see them full size.) For many pictures, HDR will not make a difference. Indeed, if the lighting is uniform throughout your picture, HDR will often make the picture look worse, taking some of the richness out of the picture. But when you have a lot of lighting contrast, HDR can make a huge difference in the quality of the photo.
HD video upload over WiFi. In iOS 4.0, you can take HD video with an iPhone 4 but need to connect to your computer to get that video off of your iPhone in full HD quality. With iOS 4.1, if you have a WiFi connection, you'll be able to upload that video so that you can more easily share HD video with others when you are on the road, away from your computer.
Fix the Proximity Sensor Bug. iOS 4 had the annoying tendency to turn the screen on when the iPhone was next to your face, meaning that your cheek could touch a button on the phone while you were talking. iOS 4.1. is supposed to fix that bug. In my limited tests last night, it still seemed like the screen was sometimes coming on when I held the iPhone close to my face, so I'm not yet convinced that Apple has completely solved this one, although I have not yet found the screen coming on when the iPhone is so close to my face that my cheek could press a button, which sometimes happened under iOS 4.0. I'll be keeping track of this one to see if it is really fixed.
Fix the Bluetooth Bug. I don't use Bluetooth with my iPhone 4 very often so I had not noticed that there was a problem with Bluetooth, but if you noticed any problems with the Bluetooth connection dropping, you'll be happy to learn that these problems are supposed to be fixed in iOS 4.1.
Enhancements to Bluetooth. In addition to fewer Bluetooth bugs, there are also more Bluetooth features with full support for the Bluetooth Audio/Video Remote Control Protocol (AVRCP). In the past, you could only adjust audio controls using a Bluetooth device such as a headset or a car stereo. Now, you can also skip forward and backward.
Speed up the iPhone 3G. iOS 4.0 was very slow on an iPhone 3. iOS 4.1 improves the speed in certain applications on an iPhone 3G. Adam Dachis of Lifehacker ran these tests and found that there are speed improvements in Safari, Photos, Messages and especially the Maps app.
Game Center. If you want to play multiplayer games on your iPhone, the new Game Center enhances the experience, allowing you to play against your friends or play against player with similar skills in certain games.
Landscape Camera Tweaks. The icons are rearranged in the Camera app when you are in landscape mode, making the button placement more consistent with what you see in portrait mode. Here is how the buttons and zoom slider were placed in landscape mode on an iPhone 4 with iOS 4.0:
And here is the button and zoom placement in iOS 4.1:
FaceTime Improvements. In iOS 4.0 you could only use FaceTime with another iPhone 4 user. In iOS 4.1, you can now use an e-mail address to initiate FaceTime, which opens the door to the new fourth generation iPod touch that doesn't have a phone number. I still wish that Apple would make FaceTime work with iChat on a Mac; I'm sure that this feature must be coming soon. Additionally, you can now add someone to your Phone favorites using FaceTime making it even faster to initiate video chats. And just like the Camera app, the buttons are rearranged in landscape mode in FaceTime.
Rent TV Shows. You can now rent TV episodes for only 99¢. You have 30 days to start to watch the episode, and then once you start to watch it, you have 48 hours before the episode disappears. (You can watch it as often as you want during that 48 hour window.) For now, this feature only works for ABC and FOX shows; hopefully NBC, CBS and other networks will jump on board soon. If you would rather own an episode, you still have the option to buy it for $1.99 (SD) or $2.99 (HD). Note that if you rent a TV show in HD, Apple says that it can only be watched on an iPhone 4; if you rent the SD version then you can watch the episode on an iPhone 3GS or 3G. Also note that there is an odd restriction involving moving a rented TV show between iTunes on your computer and your iPhone. If you rent a TV show on your computer, you can tap a "Move" button to transfer it to your iPhone to continue to watch it while you are on the go. (And at that point, it disappears from iTunes on your computer; it can exist on only one device at a time.) But if you rent a TV show on your iPhone, you cannot transfer that show back to iTunes to finish watching it on your computer.
Spell Check. In the Settings app, you now have the option to disable spell check so that you don't get the red dots under words that the iPhone thinks that you misspelled.
Parental Restrictions. In the Parental Restrictions area of Settings, you can now restrict the use of Facetime or Game Center.
New Carrier Settings. The About panel in Settings reveals that the iPhone is now using Carrier settings of AT&T 8.0 instead of 7.0 in iOS 4.0. I have no idea what is new in 8.0, but obviously 8.0 is one better than 7.0.
Auto-Lock. In iOS 4.0, you only had five choices for when the iPhone would Auto-Lock: 1 minutes, 2 minutes, 3 minutes, 4 minutes or 5 minutes. In iOS 4.1, there is a sixth option: Never. I suppose this is nice for those rare times where you want your iPhone screen to stay on even when you are not using the iPhone (and don't mind wasting the battery), but this seems to be a security flaw because it allows you to circumvent the iPhone setting that causes a Passcode Lock to be required after a certain amount of time. For example, even if your employer requires that your iPhone lock after 15 minutes of inactivity, the passcode lock screen only comes up when the screen is in Auto-Lock mode and you wake up the iPhone. If you have Auto-Lock set to Never, then your screen will never enter Auto-Lock mode, and someone could walk up to your iPhone hours after you last touched it and use your iPhone without entering a passcode (assuming that your iPhone hasn't died by then after using the battery to keep the screen lit for several hours).
Ping. Apple's new social network for music isn't really a feature for iOS 4.1; it went live last week in iOS 4.0. Nevertheless, Apple's website advertises it as a new iOS 4.1 feature, which I suppose is fair considering that it was announced at the same time as iOS 4.1. I've just started to make use of this service, but I like the idea of it and I've already discovered a few great songs.
Nike+ Uploads. If you use Nike+, you can now upload you data directly to the Nike server using the iPhone, without having to sync to your computer first. And note that even if you don't have fancy Nike+ shoes or even just the Nike+ sensor attached to another pair of shoes, Nike recently released the Nike+ GPS app that uses the iPhone's built-in accelerometer and GPS to determine how fast and how far you ran. Click here to get Nike+ GPS ($1.99): 
Security. Like every iOS update, this update addresses potential security flaws. Jeff Gamet of The Mac Observer explains: "iOS 4.1 also fixes several security issues including a flaw that could let an attacker redirect FaceTime calls with a maliciously crafted certificate, and a flaw where maliciously crafted TIFF or GIF images could be used to crash apps or run arbitrary code. WebKit for iOS received its fair share of security patches related to maliciously crafted SVG files, the handling of text nodes and element focus, fonts, HTTP redirect handling, CSS encounters, JavaScript arrays, and more."
GMail. If you use your iPhone to sync with a GMail account, iOS 4.0 added the ability to either delete or archive messages. In iOS 4.1, if your preference is to archive, then the trash can icon at the bottom is changed to an arrow pointing to a file box, which makes more sense.
One of the things that I love about iPhones is that, due to frequent software updates from Apple, the phones get better over time. iOS 4.1 is a nice update, and as noted, there are more features than I would expect for a mere .1 update. iPhone 4 owners will especially love this update because of the new features such as HDR photography and HD TV show rentals that work only with Apple's latest iPhone.
