According to a reliable rumor source (thank you!) Canon is testing prototypes of the following DO super telephotos;
- RF 400mm f/3.5 DO IS USM
- RF 400mm f/4 DO IS USM
- RF 500mm f/4.5 DO IS USM
- RF 500mm f/5 DO IS USM
- RF 800mm f/9.5 DO IS USM
According to the source, only one of these is expected to make it out of the prototype and into production. The 500mm lenses have had the best results so far, with one of them currently in the wild.
While we didn't have an RF 500mm DO IS USM on our roadmap, with current supply chain delays Canon may be forced to do something out of order with these lenses.
Interestingly, the source states that Canon hopes to announce this lens either with an actual announcement or development announcement in conjunction with the R1 announcement. The source mentions that production delays may force Canon to do just a development announcement for this lens this year. The source is certainly implying that the R1 announcement is expected later on this year.
Canon certainly could do the R1 this year, especially after so firmly stating that the R3 is most definitely not their flagship mirrorless camera. An R1 announcement later this year, would be 18 months apart from when we first found out about the R3, and 3 years since the development announcement of the 1DX Mark III.
This in the past is nothing unusual as Canon has had fairly quick turnarounds in the 1 series cameras;
|1D Mark II||April 2004|
|1D Mark III||Feb 2007|
|1D Mark IV||December 2009|
|1Ds Mark II||November 2004|
|1Ds Mark III||April 2007|
|1DX Mark II||February 2016|
|1DX Mark III||January 2020|
So there is nothing historically different from Canon releasing the R1 this year. The only oddity would be that it's far from the next summer games hopefully held in 2024 and that the major “sports” capable flagships are released during the Olympic years. But faced with stronger Nikon and especially Sony competition, Canon may be feeling the heat to release it as soon as possible.
(The EF 400mm DO is shown above as a reference)