The iPhone is definitely usable as a camera. It has numerous high speed settings, including Super Slo-Mo (240 fps @ 720p) and Slo-Mo (120 fps @ 1080p). You can also go down to 60 fps.
When you open the files, different programs will read different fps settings, but they will all be fractionally close to 240 and 120. I prefer hooking up my iPhone directly to my Mac, thereby using ImageCapture to download any images I want via a lightning to USB wire. It's much faster. You don't get a chance to specify a format when you upload them to your Mac. They will come as .MOV files, which are playable by most video players, and importable directly into Kinovea.
You will need to figure out some way to mount the camera. I've used this (https://www.amazon.com/AILUN-Rotatable- … amp;sr=8-9) and either mount it to a tripod, if you are clever enough, you can mount it to a tripod microphone stand which would give you some elevation.
This is most likely the best solution (especially if you already have an iPhone) for non-real time analysis.
If you want to go the real time route, you will need to look into machine vision/industrial cameras, 4 brands of which Joan has written plugins to support real time operation. Read more up here: https://www.kinovea.org/help/en/capture … trial.html
They start out at affordable, then go up to over $1,000. You'll need the body, a lens, and a certain amount of technical knowledge to use and install them - thus my recommendation for using the iPhone.
High Frames per second. Shutter control. Exposure control. Lots of high quality light (make sure you check these forums for the lighting users found that work well with high frame rates. I use Hykolity lights which put out bright, non-colored light that can freeze most motion (https://www.hykolity.com/collections/le … bay-lights). Best yet, they are affordably priced.
Best of luck with your dissertation!