Super 35 is the original and most common format in movie making up until recently, when full frame “hybrid” cameras have become common.
It gets a lot of hate.
The S5/5II/5IIX all crop their 4k at the extreme end and this is seen as short coming, which I get I guess as it is sold as such. The lowly G9, a dated, photo-hybrid camera can shoot un-cropped 4k/60p/420 or 4k/30p/422 as is.
Is this really an issue or just perceived to be one?
Super 35 is a variety of formats based on the original purposing of 35mm movie film, which is when it was used sideways to 35mm stills film (or the right way I guess). In digital the format is still used in many top end cinema cameras, but the actual shape varies a little.
Cropping a full frame camera gets you something like Super 35 in the much maligned and oddly named APS-C format, which is still bigger than M43 and traditionally used by many semi-pro/pro cameras. Many of the big films from the film era were shot on S35.
A screen shot from a recent M43/G9 shoot, using 1080 in standard mode, with minimal grading. So much more on offer from even S35 in the S5 in FLAT profile, but even this “bare bones” offering is enough for most uses.
I have been doing a lot of reading and watching of videos on this topic recently and it seems that apart from a 1.5x increase (= more folks, more!) in focal length, there are actually few other down sides to cropping.
The S5 in 4k does not lose quality. It is still true 4k with no loss of resolution. The sensor is actually a 6k sensor, so this makes sense.
It does not add any noise or reduce light gathering, but the smaller surface area may show noise up quicker on close inspection.
The rolling shutter performance is 100% better (from 21ms to 10.5ms), which is enough to take it from average up to the very good class of cameras.
You are using the sweet spot of the lens, which is a plus for the 20-60 kit lens for example, a lens otherwise very stable except for soft corners wide open.
The kit lens becomes a more cinema standard 30-90mm (with of course the 20-28mm option in full frame). This more normal range suits me ideally for general use. My preference is for normal perspective wide screen, not wide lens distortion and perspective.
The middle of the road 50mm in turn becomes a true 75mm portrait lens for half the price of the 85mm and the 85 then becomes a 130mm f1.8! I actually like the slightly more relaxed and natural looking 75mm over the more aggressive 85mm anyway.
More lenses become available, including the TT Artisan 35mm I already own.
The loss-less pixel/pixel mode in FHD nets you a 3x increase in focal length. The 50mm becomes roughly a 225mm f1.8 and the kit lens covers 20-270mm overall.
The variable aperture lenses also get faster for their relative focal length (30mm is F3.5 rather than about f4-5 etc). This is the secret of M43.
The stabiliser is more efficient I am guessing, because it is the case with the M43 format, but this is probably balanced by increased magnification, if it is used.
You gain a slight increase in depth of field at the same magnification for easier manual and AF accuracy. Your 50mm acts like a 35mm in these respects, so a little of the M43 advantage. Shallow depth is still possible of course, but light gathering considerations do not force you to extremes as quickly.
All formats the camera offers now come with the same parameters, so no changing of “hats” mid stream. The cameras stats suddenly become a lot more exciting without the “oh but I have to switch” holdup. For me, UHD and S35 are fine so 100% choice.
There may be a small advantage in file size or sampling rates. Not sure here.
By embracing its potential, you effectively double your lens arsenal, using full frame as the “B” option. This means you could have the 24 and 50mm lenses, with 35 and 75 as your normal working range. To me this is the ideal four and in balance*
*A wide angle is often used sparingly, but is required for some shots, the standard 50mm is also in an odd space between the often preferred and more natural 35-40mm and is not a true portrait focal length (it is a good compromise, but a compromise none the less). The 35 and 75 on the other hand are the “perfect” pair.