Canon have improved the sensors in the EOS R and RP. The R sensor is based on the same sensor we see in the 5D mark 4, and the RP is based on the same sensor in the 6Dm2 and Canon have managed to squeeze a little more out of both for some good results.
As you can see the EOS-RP sensor performs much better than the 6Dm2 sensor over the whole range of long exposure times. Canon have possibly continued to improve the manufacturing process or the new DIGIC processing is really working some extra magic. The RP is where I expected the 6Dm2 sensor to be after the fantastic long exposure performance of the original mark I. Better late then never.
The EOS-R is also better than the 5D mark IV. It’s not the same jump in sensor improvement as the RP, but it’s still a big improvement of almost 20% less noise at 1 second. Again there is consistent gains over the long exposure testing range.
So it’s a good gain for Canon, but I do feel disappointed again, just like I did when testing the 6D mark II. Canon are making consistent gains with each new model, but the long exposure sensor noise is where the competition was years ago.
When comparing the R and RP to the Z6 and Z7 based on long exposure base noise alone It would be difficult to recommend Canon, especially if you are not gear biased. The R/RP may do better for extreme long exposures of 5 mins or more, but how these models would compare with dark frames added to remove noise for extreme long exposure I don’t know.
Conclusion:
If you are currently using Canon then the R and RP are a good step up from the 5D mark 4 and 6D mark 2 in regards to sensor noise. If your thinking of upgrading to mirrorless I think both these would perform well and give good results. It’s possibly the most sensible path to go down if you have a lot of EF glass and just want to expand your kit.
The EOS-R has the best long exposure low noise sensor from Canon over 20MP, so if you are after Canon, this is the one to buy. The EOS-RP is also very respectable and not far behind. Will they be the cleanest images money can buy for long exposure?, No I expect not.
If you would like to compare the EOS-R and EOS-RP to more models, or learn more about the sensor database click here.
Again, a big thanks for Alex @Stallards in Hobart for access to these cameras for testing.