Variable apertures are staging a comeback in flagship phones, and the buzz suggests the big names are eyeing the main camera. That’s the wrong move. If Apple and Samsung want the biggest leap in real-world photos, the adjustable iris belongs on the telephoto lens, not the wide.
The premise is simple: aperture controls light and depth-of-field. We’ve seen it on phones before, from Samsung’s dual-aperture Galaxy S9 to the multi-blade designs in Huawei’s Mate 50 Pro and Xiaomi’s 14 Ultra. Those implementations targeted the primary camera. But the physics of depth and light gathering say telephoto lenses stand to gain far more.
Why Telephoto Gains More From Aperture Changes
Depth-of-field shrinks dramatically as focal length increases. At a typical 24mm-equivalent main camera, shifting from, say, f/1.6 to f/2.8 subtly adjusts background blur. At 70–120mm-equivalent—where most smartphone teles sit—that same aperture shift produces a much larger change in subject isolation and bokeh character. Photography resources such as Cambridge in Colour break down why: blur disk size scales with focal length and f-number in tandem, so longer glass amplifies the effect.
There’s a low-light dividend, too. Consider Apple’s iPhone 15 Pro Max tele at 120mm-equivalent, f/2.8. Indoors or at dusk, the camera often leans on long exposures and heavy noise reduction. Opening a tele iris from f/2.8 to f/2.0 nearly doubles the light—about 96% more—cutting ISO and motion blur without resorting to aggressive multi-frame stacking. Samsung’s Galaxy S24 Ultra runs a 5x module at around f/3.4, which is even more light-starved; a wider tele aperture would pay off immediately in cleaner 5x shots.
Stopping down the tele can be just as valuable. A narrower f/4 on a 3x or 5x lens increases depth-of-field for group portraits, distant landscapes, and tele-macro, where keeping multiple planes sharp matters. It can also tame edge softness and longitudinal chromatic aberration that are harder to fix in software.
Portraits And Low Light Stand To Benefit Most
Telephoto lenses are the default choice for flattering portraits because facial features look more natural with compression at 70–90mm-equivalent. With a variable iris, a tele can produce the kind of organic background separation that software still struggles to mimic. Even industry leaders—Apple’s Portrait mode and Google’s depth segmentation—occasionally stumble on hair wisps, glasses frames, and fine edges, as documented in independent evaluations by DXOMARK and long-running comparisons on DPReview. More optical blur means fewer algorithmic cutouts and cleaner results straight from the sensor.
Night zoom is another pain point. Secondary cameras often have smaller sensors and tighter apertures than the main, so they lag badly after dark. A tele that opens wider for Night mode would start from a stronger signal, preserving texture and color without prolonged handheld exposures. And for daytime portraiture, being able to dial between, say, f/2.0 for single-subject pop and f/4.0 for two or three people on slightly different planes gives photographers the kind of creative control that feels genuinely “pro.”
The Hardware Hurdle Is Tough But Solvable
Tele and periscope modules are already intricate: prisms, folded optics, OIS assemblies, high-Tg adhesives, and tight tolerances for alignment. Adding an iris sounds daunting—and it is. But the industry has cleared similar hurdles. Sony shipped a continuous optical zoom periscope (85–125mm) in the Xperia 1 IV. Huawei and Xiaomi proved multi-blade smartphone apertures can be robust and fast. The remaining challenge is packaging.
Vendors don’t need a cinema-grade iris to reap benefits. A two- or three-step design (for example, wide, medium, and stopped) keeps actuators simple and preserves OIS calibration tables. Placing the aperture near the tele’s entrance pupil—potentially before the prism in some layouts—can minimize added thickness. MEMS or micro-blade designs, already common in compact camera shutters, are mature and power-efficient. The result might add a millimeter or two of module height at first, but that trade-off is in line with other recent leaps like larger sensors and folded zoom.
A Better Roadmap For Samsung And Apple Flagships
Keep the main camera bright and simple. A fixed f/1.6–f/1.8 paired with today’s superb HDR and semantic rendering already delivers reliable results without the mechanical complexity. Put the variable aperture where it moves the needle: the 3x and 5x modules. Target an f/1.8–f/4 range, integrate it with Portrait and Night modes, and write the selected f-stop to EXIF for creators.
The payoff is tangible: higher keeper rates for portraits, cleaner 5x shots after dark, fewer segmentation artifacts, and less ISP churn and heat from heavy computational bokeh. Supply chain reports have repeatedly hinted that future flagships are exploring adjustable apertures; channeling that effort into the tele would yield a more visible upgrade than nudging depth-of-field on a 24mm main camera.
If variable aperture is coming—and it is—put it where physics, photography, and user delight all align. Give the tele the iris, and let the pictures make the case.
