Remember back to the good old days of March 2021, when a glint of hope surfaced showing Canon was working on a set of completely new supertelephoto designs? Canon Rumors wrote then of a patent application surfacing that showed big, beautiful, crazy-aberration-free lenses ranging from a 200mm f/2 through to an 800mm f/5.6.
Well, that patent application has now been registered as an official Japanese patent. Each lens showed adapted designs, using similar concepts, rather than throwing in teleconverting groups to double the focal length.
Everything else, in the meantime, went a little sideways. Canon recently opted to announce the release of differently-designed lenses, employing magnification lens element groups on the existing 400mm f/2.8 and 600mm f/4 options, both based on EF-mount designs from some years ago.
The expected image quality of the recently-announced production lenses – tipped off via the image height aberration graphs shown in the relevant patents – is a bit less than the quality suggested by the graphs in this new patent. The graph above shows the new patent 600mm version's expected variation from perfect (straight vertical lines). The four types of aberrations' graphs look essentially like four straight, vertical lines, and can probably be considered functionally perfect. That said, the image quality of the newly-announced supertelephotos is expected to be hard or impossible to distinguish from that of earlier Canon designs, which will disappoint few.
Canon choosing instead to run with the older EF designs, with quality-munching teleconverting elements; the much higher pricing; and the lack of RF-mount features such as allowing integrated lens and sensor image stabilization, have caused the new production announcement to land with a bit of a thud. At least among forum dwellers, and especially after Nikon launched (and last week started delivering in some countries) its short light, and three-times-cheaper 800mm f/6.3.
The lenses in the new patent, include a 200mm f/2; a 400mm f/2.8; a 500mm f/4; an 800mm f/5.6 and a 300mm f/2.8.
Because the patent's lenses all adjusted the design to the relevant focal length, none of those would produce manufacturing efficiencies compared to the announced lenses, which share many elements. This is cold comfort to Canon shooters who do not appear to be sharing in those efficiencies; the new versions costing roughly 20 percent more than earlier models.
It almost seems like Canon was caught flat footed and chose to rush this stuff to the market. Hopefully Canon will redeem itself with a genuine RF design 500/300 L later this year. The R3 is incredibly capable and deserves a lightweight modernized version of those lenses.
And you'd think with the new RF mount they would start with the 300 and 500 first before placing a built in converter to the 400 and 600 and releasing those. Its about time they come out with e 500mm f/4, the current EF version ii is long in the tooth.
So in this case, Canon filed the patent we're discussing in September 2019, the patent published in March 2021, and Japan just granted the patent.
Many patents never actually become products, so patent filings are a poor guide to buying choices. The best practice is if you need something now buy it now, and if you don't need it now, wait because there will always eventually be something better.
Ah Thank You! makes a lot of sense!
The many improved RF designs we enjoy are some enabled by the RF mount, and some are simply a new design to replace an old one. The EF 400 f2.8iii was not an "old" design. It was a new one with no need for updating or improving in any credible way that I have heard anyone articulate (it's as light and sharp as they can make it).
I do grant that they ducked the chance to add a control ring like an EF-RF adapter provides.
Maybe after several years and the next generation of the lens or body is released.
In 6 months maybe the body and lens is finally in stock and you don't have to pre-order.