Jason Hiner/

September 12's Apple event will be the most anticipated and the most watched technology event of the year, as it is each year. And as usual, the main event will be the unveiling of the next iPhone. 

Apple is famously tight-lipped about its products, does not pre-brief the media, and doesn't need to leak any information to build anticipation and interest. However, some details inevitably slip out -- usually because of the long supply chain of partners who work on various components of the iPhone.

Based on this year's list of reports about what's coming to the iPhone 15 models, here's a look at the four biggest upgrades worth watching.

1. USB-C brings one cable to charge them all

By far, the most widespread report about the iPhone 15 product line is that Apple is switching the charging connector from its decade-old Lightning port to the near-universal USB-C. This lines up because of the multiple photos that have been leaked and the fact that the European Union has mandated that electronic devices will need to use the USB-C connector by 2024 -- with the goals of saving money for consumers and reducing electronic waste.

If you're deep in the Apple ecosystem, then that means you'll now be able to use the same charging cable for iPhone that you use for your MacBook or iPad -- as well as other non-Apple accessories like cameras, headphones, the Nintendo Switch, etc. However, it also means that your existing Lightning cables and accessories will no longer work for your iPhone, although you may still need them to charge some Apple accessories like AirPods.

Also: Apple's Lightning to USB-C switch: What iPhone owners need to know

During the September event, pay close attention to see if Apple mentions whether the switch to USB-C includes an upgrade in charging speed or an upgrade to how fast you can transfer photos and videos from iPhone to Mac.

2. Periscope camera catches up to Samsung

A periscope telephoto camera lens has been one of the most anticipated -- and perhaps even one of the most customer-requested -- iPhone features of the past few years. It has long been reported to be coming to the product, or at least the Pro line of iPhones. Multiple reports from reliable sources like Mark Gurman and Ming-Chi Kuo now expect 2023 to be the first year for the iPhone to get a periscope lens, but for it to be limited to the iPhone 15 Pro Max model. There are also reports that Apple may rebrand the iPhone 15 Pro Max as the iPhone 15 Ultra to highlight its extra special-ness with the periscope upgrade.

The reason for all the fuss is that one of the last remaining types of photos that iPhone cameras don't take very well is for things far away where you have to zoom in. Even today's best iPhones only have a 3x zoom lens (you can zoom farther than that but the quality gets very pixelated). Meanwhile, Apple rival Samsung offers a 10x zoom lens in itsS23 Ultra phone -- and has been offering 10x zooms since 2020. 

Also: iPhone 16 Ultra camera will integrate biggest leap in photos since B&W-to-color

I carry a Samsung as my work phone and have been using its periscope lens since the first one was released in the S20 Ultra. The crispness and the clarity of photos taken at 5x-10x with the Samsung periscope lens have been significantly better than anything the iPhone could take for years. It will be exciting to see the iPhone finally get a stronger periscope lens to pair with its powerful camera sensors and software. We'll see if Apple goes to 5x, 6x, or 10x -- and if it brings the periscope lens to more models next year.

The Apple Event invite for the fall 2023 event to unveil the next iPhone

Apple

3. Action Button offers new level of customization

Another one of the most popular expectations for the iPhone 15 is that Apple is going to replace the Ring/Silent switch with a new Action button. This is now widely expected because of leaks from case makers who have already redesigned their cases to accommodate the new button configuration.

Also: Every product we're expecting at Apple's September event (and what won't be unveiled)

The Action button is being imported from last year'sApple Watch Ultra , which introduced the feature as a bright orange button that is user-customizable with seven different sets of functions. According to a deep dive into the code of the iOS 17 beta, the Action button that's coming to the iPhone 15 could offer user customizations with up to nine different sets of functions.

I would be thrilled to set up an Action button on the iPhone for instant camera access (and to use it as a physical shutter button). On the iPhone, it still takes several seconds to get the camera app open when the phone is locked, while on my Samsung I can double-click the power button to access the camera a lot more quickly. I've taken over 80,000 photos with the iPhone since 2007, so I average about 5,000 a year. I'm confident I'll take even more and miss a lot fewer shots if I can open the camera app with one button click even when the iPhone is locked.

4. Titanium makes it tougher, and lighter

One of the most persistent reports about the iPhone 15 during 2023 has been that Apple is changing the material of the chassis from a shiny stainless steel to a brushed titanium. This would have multiple benefits -- it would be much lighter, it would be more durable over time, and it would potentially have a more tactile and less slippery feel in your hands. 

Considering the Apple Watch Ultra is already made out of titanium and Apple has a crack team of metallurgists on staff to help innovate products with material upgrades, it's easy to be confident that if Apple is making such a key change to the iPhone's core materials then it sees clear benefits. This will likely only come to the iPhone 15 Pro and iPhone 15 Pro Max (or Ultra). 

Also: The best phones right now: Expert tested and reviewed

Recent models of the iPhone have gotten pretty heavy (240g for the iPhone 14 Pro Max), so anything that makes it easier to operate the iPhone with one hand is a good thing. And if the phone becomes less slippery and easier to use without a case, then that would be an extra bonus. 

Apple

Unlock the best new features in iPhone 15, iOS 17, and Apple Watch with these tipsiOS 17: The most impactful new iPhone features are also the ones you'll notice the leastNew iPhone 15 models compared: iPhone 15 vs. Plus vs. Pro vs. Pro MaxOne subtle (but important) reason to buy the iPhone 15 Pro instead of the iPhone 14 Pro

• Unlock the best new features in iPhone 15, iOS 17, and Apple Watch with these tips
• iOS 17: The most impactful new iPhone features are also the ones you'll notice the least
• New iPhone 15 models compared: iPhone 15 vs. Plus vs. Pro vs. Pro Max
• One subtle (but important) reason to buy the iPhone 15 Pro instead of the iPhone 14 Pro