If you thought Apple’s 4x tetraprism telephoto on the iPhone 17 Pro was already wild for a phone, Sandmarc just turned things up to “that’s not a smartphone anymore” levels. The company’s new Tetraprism 72mm lens snaps onto the iPhone 17 Pro’s telephoto camera and effectively pushes total zoom all the way up to 24x, while still giving you real optical reach instead of a mushy, overcropped digital mess.​

At the heart of this whole setup is Apple’s 48MP Fusion Telephoto camera on the iPhone 17 Pro and Pro Max, which already delivers a true 4x optical zoom at a 100mm equivalent focal length using a tetraprism design that folds light multiple times inside the phone. On its own, that lens can get surprisingly close, and Apple uses the high‑resolution sensor to give you high‑quality 8x “optical‑quality” zoom by cropping into the 48MP image. Sandmarc’s 72mm glass doesn’t replace that; it sits in front of it and adds another 3x layer of optical magnification on top, which is how you get to that headline 24x number.​

Numbers-wise, Sandmarc says you can shoot at up to 12x optical zoom while still pulling a full 48MP image from the telephoto sensor, and if you’re okay dropping to 24MP, you can push to 24x without relying purely on software zoom. That’s a pretty big deal: you’re not just pinching to zoom on the iPhone viewfinder and praying the image isn’t unusable when you zoom in later – you’re actually stacking glass in front of glass to get real reach. Think of it like a teleconverter on a mirrorless camera: not something you leave on all the time, but a serious tool when you need distance.​

Sandmarc is clearly targeting people who care about image quality, not just zoom bragging rights. The 72mm lens uses a multi‑element, multi‑coated glass design, which is what you’d expect from a decent interchangeable lens, and the company claims it’s tuned to maintain sharpness and color accuracy at long distances while cutting down on flare. The signature “compression” you get from longer focal lengths is part of the appeal here too – that stacked, layered look where mountains, buildings or city lights feel like they’re right on top of each other, something you normally associate with 200mm‑plus lenses on dedicated cameras. Sandmarc explicitly calls out landscapes, cityscapes, wildlife and live events as use cases, which makes sense: this is the sort of lens you strap on for a hike, a safari, or the cheap seats at a concert.​

The 72mm isn’t arriving alone, either. It slots into Sandmarc’s existing lineup next to the 48mm Tetraprism lens, which provides 2x magnification and is meant for a slightly shorter tele reach. Both the 48mm and 72mm versions are designed to mount directly over Apple’s tetraprism telephoto, working in tandem with that 100mm‑equivalent module instead of trying to adapt over the main camera as many older clip‑on lenses did. The new 72mm model weighs around 180 grams, so it’s not exactly subtle; once you’ve mounted it using Sandmarc’s case and filter system, your ultra‑sleek iPhone suddenly looks a lot more like a compact camera with a bolt‑on telephoto.

There’s also a software twist you need to care about. Because Apple’s stock Camera app loves to silently switch between lenses to keep exposure and focus stable, Sandmarc recommends using a pro‑grade third‑party camera app like Halide or Blackmagic Camera. Those apps let you lock the iPhone 17 Pro to its tetraprism telephoto module, so the phone isn’t suddenly jumping to the main camera and digitally cropping when you’ve just mounted a fairly serious piece of glass over the telephoto. It’s one of those “advanced user” details that will trip people up if they just snap the lens on and leave everything in auto, but anyone who has shot manual on an iPhone before will be right at home.

Compatibility-wise, the Tetraprism 72mm lens is at its best on the iPhone 17 Pro and 17 Pro Max, where you get the full 24x zoom story, but Sandmarc also supports the iPhone 16 Pro, 16 Pro Max, and iPhone 15 Pro Max with a lower ceiling of up to 15x zoom. That’s still plenty of reach for wildlife, sports, or candid street shots from a distance; it just won’t match the 17 Pro’s newer 48MP telephoto and its 4x base magnification. If you’ve already bought into Sandmarc’s ecosystem, the 72mm slots into their case and filter system, which means you can pair it with their ND filters or other accessories and treat the whole setup more like a modular camera rig than a typical phone.​

Of course, none of this comes cheap. The Tetraprism 72mm lens is priced at around $299, while the existing 48mm version sits at roughly $249. At those prices, you’re in the same ballpark as an entry‑level compact camera or even a used mirrorless body with a basic telephoto zoom, which is exactly why the online reaction is mixed. Some photographers argue that if you’re going to carry a 180‑gram lens anyway, you might as well bring a dedicated camera for even better optics and control, while others point out that the advantage here is convenience: your shot is already on your phone, ready to edit and post, without dumping RAW files or juggling SD cards.​

That “best camera is the one you have with you” cliché hits a little differently in this context. On one hand, adding a sizeable chunk of glass to the back of an iPhone absolutely kills the minimalism that makes phone cameras so appealing. On the other hand, for hikers, travelers, creators and even pros who already rely on their iPhone as a main or backup camera, having a 24x optical‑leaning option in the same ecosystem is genuinely attractive. Imagine a travel creator shooting 4K video at 24mm on the main camera, then switching to the tetraprism telephoto with the 72mm lens attached to grab compressed, cinematic B‑roll of far‑off details – all on a device that also runs CapCut, LumaFusion or Final Cut for iPad‑style editing workflows.​

Underneath the hype, this launch also says something interesting about where smartphone photography is going. Apple has already pushed as far as it reasonably can with internal optics, folded tetraprism designs and computational photography to deliver more zoom without turning the iPhone into a point‑and‑shoot brick. Accessory makers like Sandmarc are effectively picking up from there, saying: “Okay, if you’re willing to bolt on extra glass occasionally, we’ll give you reach that rivals entry‑level telephoto setups.” It starts to blur the line between phone and camera even more – you can stay in the Apple ecosystem, but treat your iPhone more like a modular body that gets better or more specialized depending on the lens you clip on.

So, who is the Tetraprism 72mm really for? Probably not the casual iPhone user who just wants nicer vacation pics – the built‑in 4x telephoto and Apple’s image processing are already more than enough there. This lens feels built for enthusiasts, mobile filmmakers, travel creators, and that niche of users who genuinely prefer to push a phone to its absolute limits before committing to a separate camera system. If you live in that world, 24x zoom on an iPhone 17 Pro isn’t just a fun spec sheet flex – it’s one more reason to leave the big camera at home and still walk away with shots you wouldn’t have dreamed of getting from a phone a few years ago.