Even for DSLRs corrections were possible in post processing, but there are many good reason to buy a lens that gets rid of all those optical problem with physics instead of processing.
There are also good reasons not to – more correction generally requires more complex designs with more elements, meaning greater weight and higher cost.
While photographers often used Photoshop to "lie" to the viewers, now the cameras use algorithms to lie to the photographer. If you can't even turn off those lens corrections in the viewfinder, that is a major problem.
There are also advantages to seeing the corrected version in the viewfinder. Even lenses 'corrected with physics' aren't perfect. Notably, expensive L-series EF UWA zooms have plenty of barrel distortion and vignetting. Say you frame an image with the EF 11-24/4L at 11mm carefully in a DSLR viewfinder, or in a MILC EVF with the corrections disabled. When you later correct the ~7% barrel distortion in post-processing, you find that the edges of your carefully framed shot have been eliminated, and elements that were visible in the VF are not present in the corrected image. Seeing the corrected version when composing the image can be advantageous.
It shocks me that Canon even seems to be proud that their future lenses let their flaws get corrected by the camera. ... Those new lenses are not even cheaper than the old ones.
If they can offer a lens that costs less to produce but otherwise delivers similar final images, that means more profit for them – I'm sure they are proud of that, although it doesn't benefit the consumer. However, if you factor in inflation between the release of the EF version and the RF replacement, there's not much difference and some RF lenses are actually cheaper. The additional cost is generally getting you more features – wider ultra wide lenses, longer telephoto zooms, smaller/lighter lenses, greater maximum magnification, etc. The one obvious case where the lenses are basically identical is the 24-105/4L, and for that lens the EF MkII and RF versions launched at the same price (and the RF is cheaper with inflation factored in).
In other cases, some lenses are released at prices that are really a bargain. There's no way a 'corrected with physics' 16mm f/2.8 lens would be sold for $300.
The heavy distorted 14-35 is really expensive, but for that price Canon does not even deliver a lens that produces photos with low distortion without the help of software.
I highly doubt a 14-35mm f/4 zoom having low distortion could be designed that would weigh 540 g (the EF
16-35/4 is ~14%
heavier than the RF despite being 2mm narrower), and using a 77mm front filter. It's also with noting that by 16mm, the RF 14-35 has ~5% distortion, and at the wide end the EF 16-35/4 has ~4% distortion. So you can sort of view the RF lens as giving you similar performance across the overlapping zoom range, but also giving you an extra 2mm of focal length at the wide end that needs additional corrections, but doesn't cost you anything in terms of weight or size (but does cost you more money).
If Canon continues that route, I might buy a mirrorless camera one day, but only with old EF lenses.
That's your prerogative. IMO, some of the RF lenses have significant advantages over their EF counterparts. Others, like the RF 28-70/2, have no equivalent.
www.usa.canon.com
