Next year, Apple (AAPL -1.22%) is expected to launch three new iPhones. The lowest-cost of the bunch is expected to be a device with a 6.1-inch liquid crystal display (LCD), which means the display won't be as high quality as the organic-light emitting diode (OLED) displays on the successor to this year's iPhone X and its rumored larger counterpart

Analyst Ming-Chi Kuo with KGI Securities said in a research note a while back that the specifications of the 6.1-inch LCD iPhone would "differ significantly from the OLED models in hardware and design specs." At the time, Kuo didn't share too many specifics on the differences in hardware specifications, but since then, some details have trickled out. 

Apple's iPhone 8 Plus (left) and iPhone 8 (right).

Image source: Apple.

The latest rumor, which comes from Nomura Securities (by way of BusinessInsider), is that the 6.1-inch LCD iPhone won't have a dual-lens rear-facing camera, as today's iPhone 8 Plus and iPhone X do. Instead, it'll apparently have a single-lens camera, as today's iPhone 8 does. 

At first blush, this is a bit surprising. Considering dual-lens cameras are rapidly finding their way into relatively low-cost phones, I'd have thought that Apple would've wanted to put this spec in a device that, according to Kuo, will sell for $649-$749. 

However, upon further consideration, this rumor does make sense. Here's why. 

Keeping cost structure in check

Thus far, the other rumors about the 6.1-inch LCD iPhone point to a device that'll have the latest wireless connectivity capabilities (e.g., cellular, Wi-Fi) as the higher-end OLED models. In addition, the 6.1-inch LCD iPhone is expected to include Apple's 3D-sensing TrueDepth camera as well as a new full-face display. 

The 3D-sensing camera will surely add cost, as will the shift to an all-new display, even if that display is based on proven and plentiful LCD technology instead of newer, scarcer OLED technology. 

Apple's iPhone 8 running a complex 3D game.

Image source: Apple.

In addition, a new report from Kuo, by way of MacRumors, claims that the 6.1-inch LCD iPhone will include a large battery with a capacity of between 2850 and 2950 milliampere hours -- up substantially from the iPhone 8's 1821 milliampere hour battery.

Larger battery capacity means longer battery life, but the larger battery is sure to add cost. So Apple may be looking to help rein the cost structure of the 6.1-inch LCD iPhone by going with a single lens camera -- especially if that camera is substantially improved compared with the one found in this year's iPhone 8 -- rather than a dual-lens camera. 

Product segmentation

It's also important to keep in mind that the 6.1-inch LCD iPhone will be at the bottom of a product stack with three devices in it. Apple, of course, would rather potential customers buy a 6.1-inch LCD iPhone than no iPhone at all, but at the same time, it'll want to reserve features and capabilities for its more expensive devices to give customers incentive to pay a bit more to get better devices. 

To that end, if Apple does indeed stick the 6.1-inch LCD iPhone with a single lens camera, then the dual-lens cameras that will surely be on the 5.85-inch and 6.46-inch OLED iPhones will be clear selling points for those devices.

Some iPhone buyers might not care about the dual-lens functionality, but considering the popularity of the iPhone 7 Plus and iPhone 8 Plus relative to their smaller counterparts, it seems clear that a dual-lens camera is something many iPhone buyers are willing to pay extra for. 

So, in the interest of encouraging customers to buy either the next-generation iPhone X or its larger counterpart, Apple may limit dual-lens camera functionality to those devices.