Is 4k needed for your film?
There are many articles and videos all over the internet talking about whether 4k matters.
Many will say 4k is absolutely necessary and others will say 4k doesn't matter.
So what is the right answer?
There's a difference between Want and Need.
Here's a couple questions to ask yourself when your trying to figure out if you need 4k for your project.
What project are you working on?
Where will the project be shown?
All of these things affect what you will need to complete the project.
In the same way you would choose the right actor for the right part, you would choose the right camera for the right job.
Where and When?
Lets compare these scenarios.
Music video for web
Lets say you are filming a music video but you are told it is only going to be displayed online on a website.
In this situation I might film in 4k and use the extra resolution to reframe some shots that could be off, in the end I would render out a master 1080P file for them, not 4k.
For this it is beneficial to you to have 4k for editing but not for a master export.
Corporate Work for T.V.
In this situation you are asked to shoot a corporate video for a company that will air on T.V.
In this situation there is no need to shoot a video in 4k that will never be seen in it's true 4k quality. Normal broadcast T.V. is not there yet and mostly only broadcasts at 720 x 480 30fps.
Now you have an option here and you can decide if the extra time of handling and editing 4k files over 1080p files is worth it to end up with a requested 1080p file that will air at less than 720p.
There are other factors that weigh into this choice as well, that includes how much you plan on color correcting/grading (assuming your camera shoots 4k 4:2:0 8bit or 1080p 4:2:2 10bit) and if you plan on future proofing your work.
Ultimately it comes down to you the filmmaker assessing what is needed of your project and handling it in the most efficient way.
Don't shoot 4k because everyone says its the only thing worth watching or because they say 1080p is dead.
In my opinion there is no Right answer. It all comes down to what you Actually need in the end.
Make the choice based on what YOU need and your project will benefit from it.