Canon R5 vs R6 vs R7: Best for bird photography, EF lens compatibility

[Viandre]

Hi

I have a Canon EF600 mm 1:4 L IS II USM Lense.

Currently I use 7D Mark II body and want to upgrade to mirrorless.

We use the body primarily for Bird Photography and Wildlife.

What will be the best fit for birdlife photography that compatible with my lense?

[p4pictures]

EOS R5 Mark II might be the ideal choice. It has the latest generation of mirrorless AF system, and would also deliver 20MP images even when used in 1.6x crop mode where your lens would look the same as it does on the EOS 7D Mark II. You will also gain pre-shooting where a series of images can be captured from the 1/2 second before you press the shutter. Of course it is also the most expensive choice.

EOS R6 Mark II is my second suggestion, it has great low light AF and high quality even at higher ISO settings. However as it is only 24MP on full-frame, to get the same reach as you are used to with your 600mm and EOS 7D Mark II you'd need to use crop mode and that results in 9.3MP images.

Lastly the EOS R7, great high resolution camera, but needs a little more light than the other two to deliver the best quality. 32MP on an APS-C size sensor means the pixels are as big as 80MP on a full-frame camera. Also some have found that the AF can't keep up with the fastest frame rate in electronic shutter mode.

One of the most important things to know is that when you move to a mirrorless one, it will take some time and likely a different way of using the AF to get the best from these camera's capabilities, but this is worth it for the increased rate of in-focus shots. 

[johnrmoyer]

I went from EOS 80D to EOS R5. I found that I had to change how I do things, but the eye detection auto focus is a big improvement. I am acquainted with a local ornithologist who uses the EOS R7 and gets better photos than I do. One of his photos of a rarity for this area is at https://macaulaylibrary.org/asset/625146302 where one might notice it is heavily cropped. The EOS R7 allows more cropping than the EOS R5 because there are more pixels on the bird.

I do not have any RF lenses and all of my EF lenses work better with the EOS R5 than with the EOS 80D. I often use my EOS R5 in 1.6x crop mode and get a few less pixels than my EOS 80D, but get improved eye detection for small birds. I can switch to full frame for a larger or closer bird.

If the goal is documentation of bird sightings, then I think the EOS R7 is better. For art photos in low light, I think that a full frame sensor is better.

One of my photos for a rarity in this area during the Christmas bird count is at: https://macaulaylibrary.org/asset/628198491 and the photo I uploaded is:

Dark-eyed Junco (Pink-sided) Junco hyemalis mearnsi in Norman, Oklahoma, United States on December 29, 2024

Description	Dark-eyed Junco (Junco hyemalis) in Norman, Oklahoma, United States on December 29, 2024
Software	Digital Photo Professional
FNumber	8.0
ExposureProgram	Aperture-priority AE
ISO	2500
ShutterSpeedValue	1/664
FocusMode	AI Servo AF
RecordMode	CR3+JPEG
CanonModelID	EOS R5
AFConfigTool	Case 1
AFTrackingSensitivity	0
AFAccelDecelTracking	0
AFPointSwitching	-1
AIServoFirstImage	Equal Priority
AIServoSecondImage	Equal Priority
USMLensElectronicMF	One-Shot -> Enabled (magnify)
SubjectToDetect	Animals
EyeDetection	On
RollAngle	0.5
PitchAngle	-4.3
FocalLength	560 mm
LensModel	EF100-400mm f/4.5-5.6L IS II USM +1.4x III
FileName	IMG_2484.dr4
AngleAdj	0.5
WorkColorSpace	sRGB
RawBrightnessAdj	-0.67
WhiteBalanceAdj	Daylight
WBAdjColorTemp	5200
ColorSaturationAdj	2
UnsharpMaskStrength	2
UnsharpMaskFineness	4
UnsharpMaskThreshold	3
LuminanceNoiseReduction	4
ChrominanceNoiseReduction	4
DLOSetting	40
DPRAWMicroadjustBackFront	1
DPRAWMicroadjustStrength	8
CropRotatedOriginalWidth	5117
CropRotatedOriginalHeight	3436
CropX	1714
CropY	1005
CropWidth	2400
CropHeight	1600
CropRotation	0
CropAngle	0.5
CropOriginalWidth	5088
CropOriginalHeight	3392