So, what makes that “cinematic” look?
Most obvious is the different Aspect Ratio (AR) of course. While the classic 35mm photography sticks to its 3:2 ratio ever since then, TV moved from 4:3 to 16:9 not that long ago but cinema went into widescreen land already during the fifties. Over time, there has been quite a number of different widescreen formats introduced, starting with Cinerama or later on that classic Cinemascope look which constitutes an AR of 2.35:1 by utilizing anamorphic lenses. Other formats go even wider and if you are interested in that topic I can highly recommend to watch this excellent and comprehensive summary about it.
Working within different AR’s already affects image composition or, even deeper, the visual language as a whole. While some composition techniques apply across all ratios (e.g. the rule of thirds) it’s obvious that a scene is cropped in quite a different manner depending on the actual AR. Shooting a face close-up on a 6×6 medium format film might fill the whole frame with just that face whereas within a 2:1 format just half of the frame actually contains the face and/or the face might be heavily cropped on bottom and top.
Indeed we can see a lot of cropping going on in widescreen format movies and not only if it comes to close-up’s – it seems that everything goes as long as the subject can properly be spotted. Spotting whats relevant is further supported by strong background separation. Utilizing strong background blur is just one method to achieve this and there are many others like color separation or just simpler structured background compositions. While in still photography composition techniques such as layering can be used to create rather complex scenes, in moving images this rather tends to be avoided. Here, complexity evolves over time instead, frame by frame.
There are a couple of artifacts from lenses and film itself which also contributes to a distinct look. The very first widescreen formats were created with anamorphic lenses whose design introduces some side effects, most prominently that typical lens flare look. Even today such lens designs are still produced and in use to obtain that special look. The analog film itself creates a look on its very own due to the specific color rendition and saturation behaviour. Within digital post-production, additional color grading techniques emerged to give an entire movie a distinct and unique look, to emphasise a certain mood or just to avoid a too sterile look if the footage was already filmed digital.