Can a Phone Even See a Golf Ball Going 150 mph?

Dev blog #2. Last time I explained why I started building an Android launch monitor. This time, the question that had to be answered before I'd written anything worth keeping.

Every project has one question hiding underneath it that you're a little scared to ask out loud, because if the answer is no, there's no project. For Trackeon, here it is: when you catch a driver flush, the ball leaves the face at over 150 miles an hour and is basically gone in the time it takes to blink. Can the camera in your pocket actually see that? Clearly enough to measure it, not just film a pretty smear? What are the minimum camera specs required to do this consistently?

I had educated hunches from my time working with Android cameras but hunches are worthless. So before I let myself fall in love with the idea, I went to find out for real.

Why this is the only question that mattered

Here's the thing about a launch monitor: every number it gives you is built on top of the camera actually seeing the ball. If the ball shows up as a clean, findable shape in enough frames, you have something to work with. If it's a faint blur lost in the grass and the glare, then it doesn't matter how clever the rest of the app is. You can't measure what you can't see.

So this wasn't a "nice to confirm" detail. It was the foundation. I didn't want to spend weeks building on sand, so step one was the least glamorous thing imaginable: go to the range, set a phone down behind the ball, and hit shots. Lots of them.

What the phone actually sees

This is the part that surprised me most. We're all used to our phones taking gorgeous, crisp photos. But the moment you ask a camera to work fast enough to catch a golf swing, you trade away a lot of that polish. Here's a single frame from one of those high-speed sessions, straight off the sensor:

Look at how small the ball is. Look at how little separates it from the turf behind it. Now imagine that ball not sitting still but tearing across the frame, and you start to feel the size of the problem. This is the honest, unglamorous reality underneath every slick launch-monitor number you've ever seen: it all starts with a small, grainy smudge and a lot of stubbornness.

So... can it?

I'll be straight with you, because that's the whole point of writing these as I go. The answer I walked away with was yes, but. Yes, there's real signal in those frames. Yes, a phone can capture enough to build a launch monitor on. And also yes, there's a long list of "buts" that turned into the next several days of work, and a few of them genuinely kept me up at night.

Exactly how I get from that grainy little dot to trustworthy numbers is the part I'm going to keep behind the curtain for now. That's the tricky part, and it's the reason Trackeon exists instead of being a weekend experiment. But I'll happily walk you through the problems I ran into, one post at a time, because honestly they're the fun part.

Next up: filming the fastest two milliseconds in golf, and why getting a phone to capture impact reliably is harder than it has any right to be.

If you want to follow along, the best way is to pre-register and stick around. See you on the range.