R3 with 1.4 TC or R7

Zcarxrg wrote:

I am an "enthusiast" bird photographer trying an apples to oranges comparison between the Canon R3 and upcoming Canon R7 camera to determine which would be a better purchase for me. I don't shoot at set up blinds and prefer action photography over stills. I currently shoot an R5 or 1dx II with a 600 MM f4 IS II, Canon 400 MM DO IS II or Canon 100-400 mm IS II. I am pleased with the overall results I get using any of those lenses and a 1.4 Teleconverter. The R5 often takes more time to acquire focus than the length of an event that I am trying to acquire unless the R5 is pre-focused near the focus distance required for the shot.

Replacing my 1dxII with one of these two options is the goal due to the focus tracking superiority, increased resolution and frame rates available and the ease of capturing occasional viewfinder based videos. I usually carry both the r5 and 1dx II on primes as my "zoom" option.

My comparison is based on using the 1.4 type three teleconverter on the 24 mpix R3 or having a bare lens on the 32 mpix R7. I am expecting to have superior focusing abilities with the R3 and 1.4 TC than the R7 due to technical design, battery type and marketing position. My example is based on having an R3 combo providing a 560 mm equivalent field of view vs an R7 cropped equivalent 640mm field of view considering using a 400 mm lens on either camera. I want to consider the crop sensor R7 so I can carry smaller lighter glass and potentially get better detail with the 32 mpix sensor.

I am also considering Canon's own documentation stating that the perceived resolution of the R3 is more like that of a 30 mpix sensor and that the expected 32 mpix of the R7 requires a pixel size and density equivalent to a full frame sensor of more than 80 mpix. I have to expect a significant ISO noise penalty with the R7 compared to the R3 since 1/2000 is considered my minimum shutter speed except on large birds in flight.

While I can afford the R3 ( a used one may be available at $5 - 5.5 K ) I still have to consider price a factor. Considering price it might also make sense to consider that I could get the R7 and the RF 100-500MM lens for about the same cost as the R3 alone.

Ideally, bird in flight shooters and action wildlife shooters using the R3 would comment here. Thanks in advance....

As with most discussion I fully expect this to be more about compromises and "discussion" vs "conclusion".

This is no longer discussion worthy.  The R7 is not the APS-C version of a pro camera that the 7D series was and should have been called an R8 or maybe an R9 to leave space for a true 7Dseries replacement and maybe another camera in between. Before announcement the indications that the camera was using two sdxc uhs II cards was a red flag, perhaps telling about the size of the camera and even more worrisome, the buffer size- which appears to be about 60 frames in 30 fps electronic mode, even with the fastest and most expensive memory card on the market .  The idea of the R7 being a replacement for the 7d series meant it would be very much like the R5 and R6 and be in a similar body size just like the 7d Series had the same body and controls layout as the 5d series. Instead the camera appears to aim at the Sony 6600 in a body that requires a battery grip for many users and has ergonomics which make it a difficult backup for the R5 or R6 cameras.  I was hoping the R7 would have the shooting capabilities to make it worthy of the $2000 to $2700 pro-level camera some were expecting but that did not happen.