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

[ctitanic]

I completely agree with Brian's words—I couldn’t have said it better myself. Any of those cameras will pair well with the EF600mm f/4L lens. The only addition I’d recommend is a 1.4x extender, which will provide the extra reach you're accustomed to with the R7 or currently achieve with the 7D.

As a former R7 owner, I would personally avoid this camera due to its autofocus issues, especially with rumors circulating about an R7 Mark II release this year. Additionally, I’ve read numerous comments from 7D owners who purchased the R7 expecting an upgrade, only to find themselves disappointed.

[ctitanic]

Nice picture!

[johnrmoyer]

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@ctitanic wrote:

Nice picture!

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Thanks!

[hobs1466]

Unfortunately the R5mkII is out of my price range, even used. So how you put a used R5 ahead of the R6mkII?

I have a 90D hopefully being repaired, but am planning in case it can't be. I was immediately drawn to the R7 because I am used to the APS-C reach and do some amateur bird photography. However, after reading about AF issues for fast shots and poor(er) low light performance (I also do astrophotography) I started looking at the R6mkII. But **bleep** I hate to give up that reach. I'm starting to think my best bet to stay at or under $2K is the R6mkII and a teleconverter.

But then someone recommended a used R5 which has a big enough sensor that even in crop mode is usable. Though the older AF system.

[March411]

The R6 MkII performs better in low light than the R5. Dawn and dusk the R6 MkII was my go to body. If you have denoise software the point is moot. Depending on the lenses you own the Canon EF/RF adapter would be your best bet, some third party adapters don't play well with the lens to body communication protocols. All that being said the R5 is an outstanding body, more megapixels but a bit higher cost. 

The R7 is a decent camera but getting it set up to take advantage of the AF is a challenge. I finally have mine tweaked and my hit rate has greatly improved. It really struggles in low light and contrast. This is an interesting video on the R7. Duade's suggestions put me on a better path. 

The link below is for EF lenses supporting burst which may interest you since your focus is wildlife. You'll find a full list of Supplemental Information on Compatibility on the left margin

Lenses Supporting Maximum High-Speed Continuous Shooting Speed 

Edited post because I wanted to add some information on the R7

[TomRamsey]

I bought the R6 Mark II to pair with the RF 200-800 for birding and other wildlife.  Besides the excellent autofocus, 24 MP full frame means that it has bigger pixels and therefore gathers light really well.  I am completely happy with the camera (and lens).  Here are a few recent bird shots showing a couple with large crops and a couple uncropped:

Female Red-winged Blackbird, uncropped:
Female Red-winged Blackbird

Saltmarsh Sparrow, Significant Crop:Saltmarsh Sparrow

Brown-headed Nuthatch, significant crop:

Brown-headed Nuthatch

Green Heron, uncropped:

Green Heron

[March411]

Great light on that second image Tom!