In the backstage videos of music videos, you can see that camera operators are filming with small video cameras.
In the backstage scenes of TV shows, you can see that cameramen are filming with large cameras that they carry on their shoulder (or mounted on a tripod).
Comparing the quality of music videos and recordings of various shows posted on YouTube by TV channels, I do not find any difference.
It seems that small video cameras shoot just as well as large video cameras.
What is the difference?
Maybe for you, but I generally can.
Bigger cameras have bigger sensors. This means they can process more light, amcan get more detail, and have less noise.
The gaps between large triple ccds and smaller single ccds has certainly shrunk. But if a professional has to get the best possible result in all sorts of environments while not wasting time/money, buying a proper camera that isn’t going to need as much post processing, or as many lights (especially with multiple subjects) is going to be a huge timesaver.
Kinda like photographers with a DSLR Vs an iPhone. The difference has become less, but a DSLR is going to kick an iPhones ass every time.
Next up is the lenses.
If you have a small lens with a defect, more of the picture is going to travel through that defect.
If you have a large lens with a defect, a smaller amount of the picture is going to travel through that defect.
Also, lenses generally have more abberations towards the outside of the lense (like barrelling or chromatic aberration). If you can only process light from the middle of the lens, the picture is going to be so much better.
So you make big lenses, and only use the but in the middle of them.
Finally it’s things like other features.
From encoding format, framerate & resolution, outputs (clean feeds, native sdi or SMPTE fibre, remote CCUs, return feeds, coms), genlock and timecode syncs. Even to things how the viewfinders, zoom and focus controls work.
And by the time you are making a $100k camera with $250k lenses, it’s kinda a thing that works for sports, film, TV, whatever. There is a lot of overlap of features, and nobody wants to buy the same lens for 2 different cameras because the cameras are slightly different.