Is there any software available which would allow me to use an iPhone 4S' camera as my MacBook Pro's iSight camera? I am specifically looking for something that would allow me to use my iPhone as New Movie Recording via QuickTime Player. Anything would be appreciated, really. Thanks!
I don't like to disappoint you, but I think the chances are small.
These kind of camera follows a hardware protocol, and it will take a incredible amount of code to make it work.
Possible, but difficult. Plus, 1080p or even 720p from iPhone to MacBook Pro, I think the quality will be relatively poor.
A real web camera with support up to 1080p won't set you back a lot, take a look at some. I think they might be better at stability and stuff, after all that's what they're made for.
If you don't want to use it as iSight, just a video recording device that records directly to you Mac, here's a way.
AirPlay mirroring can mirror your iPhone display to Mac (actually Apple TV, but there's an app for that), and then record that. An app called Reflector (https://www.reflectorapp.com) made it really simple with built-in recording feature. You can show the camera app and record that. Of course that comes with a cost of ugly camera bar. I think you can find an app that shows camera without any distraction. And the end result is pretty outstanding considering it's over WiFi and
There is another way, video call to your Mac, and record that. But that's way too complicated.
There was once a project called iPhoneCam which allowed you to stream your iPhone video over WiFi to your Mac, but it seems like this project never got released.
I haven't tested it myself, so I don't know for sure if it will work. But it should do the trick according to the developers.