Originally posted by photoptimist The rapid growth of the smartphone camera shows that the vast majority of photographers (in the broadest sense of the term) do not care about sensor size. Tiny sensors (+ clever noise reduction algorithms) are good enough and getting better. It's only the upper echelons of the photography market that want big sensors in order to get the highest-possible DR, narrowest depth of field, and highest usable ISO. Yet the same physics that makes big sensors great at collecting light makes then hard to read-out the data fast enough for good video and low-lag EVFs. Physics also makes optics a lot larger and more costly for larger sensor cameras.
The larger issue is that the photography market will NEVER converge because photographer's needs and desires will never converge. Some want big cameras, some want small ones, some want high-reach, some want large aperture, some want video, some don't care about video, some want OVFs, some want EVFs, some want 20 frames-per-second, some take one frame per hour. Add in brand loyalty issues and user interface preferences, and there's room for lots of formats from lots of makers.
In an ideal world there would be room for lots of formats from lots of makers but I'm not sure that is borne out in practice either on film or on digital. The reason is pretty straightforward: the camera companies are businesses. They need to make a profit. That is best effected by creating a large market for near-identical products which turn benefits from efficient and economic mass production standardized on mass-produced components. I'd have thought this process is turbocharged in the digital era when R&D costs have increased exponentially and sensor design and fabrication are so costly that the biz has centred on just a handful of companies worldwide. So, for example, while plenty of people might greatly like M43 cameras, it might be that simply not enough of them are prepared to spend what it takes to make M43 a viable business proposition, at least in future. The cost now of maintaining any digital platform is so large that you need a lot of customers and a lot of money coming in to make it viable, far more than in the analogue era. The same could apply to almost any other format.
The tempting standardizer here of course is FF, the format that is distinctly large enough for those upper echelon photographers and which enjoys economies of scale through the vast amount of legacy material still available for it from the DSLR manufacturers. Buy a body, dip into countless millions of still perfectly good FF legacy lenses. I'd have thought there is quite a chance of a bit more standardizing on FF in coming years and fewer smaller formats. Many might not like that but, as they say, nothing personal it's just business.