Canon R1 has been announced

[DavidEccleston]

I'm going to assume the R8 sensor will be similar to the R1's, as they're both 6000x4000 full frames, and can just compare my R8 and R7. In theory I should be able to mount the 100-500mm on a tripod and just swap bodies, giving the exact same shooting conditions. I just need to figure out a static subject with enough fine detail to be useful. I know the R8 has a crop-shooting option for video, and when using RF-S/EF-S lenses... I'll have to see if I can force that mode on when using an RF lens, so they'll frame identically. I'm actually curious how this will turn out.

[Kayaker72]

I went with the pragmatic/real world comparison as to a large extent the "laboratory" comparison (tripod, controlled lighting, etc) is what Bryan does in his resolution tests.

R7 vs R8

R1 vs R5II

Getting into the weeds a bit (and warning, you can just look at the charts), MTF charts are 10 lp/mm (line pairs per mm) and 30 lp/mm. Byran's chart maxes out at a resolution of 4000 lines per image height. Doing the math, 4,000 / 2 (lines in a line pair) / 24 mm (image height of FF sensor) and with FF sensors, his chart maxes out at 83 lp/mm.

Lenses used to not even be that good.

More math, but the R8 and R1 have 4000 vertical pixels, so they also theoretically max out at ~83 lp/mm. R5 theoretically maxes out at ~113 lp/mm. R7 theoretically maxes out at ~155 lp/mm. As the sensor height is different for crop sensors, the 4000 vertical lines on a crop sensor camera, Bryan's chart has a maximum a resolution of ~134 lp/mm.

That is a long way of saying, Bryan's chart matches the resolution of the R8 and R1, but the R5 and R7 theoretically out resolve his chart.

Next tech bit, but the darker the lines the better. The distinctive white/black lines is the goal, as they get more gray you are losing resolution. MTF50 is the black being 50% of desired (roughly speaking). True resolution loss is something like MTF8, where you cannot distinguish between white and black lines.

Hitting "ctrl" and the plus sign, you can enlarge the image of Bryan's chart. To my eye, both 24 MP sensors are at their resolution limit as the lines hit the black square, and starting to gray as the resolution increases as the line moves into the square. The R5/R5II/R7 the lines are gray, but they do out resolve the 24 MP sensors.

This is part of how I justified the R1. We are talking about out resolving charts! We are talking about 83 lp/mm, which lenses used to not be capable of doing. We are also talking about a point where any vibration/movement will ruin that resolution advantage.

[DavidEccleston]

Based on the minimal size change from the R8 and R7 charts you link, and Bryan's desire to get the full chart in the shot, he is changing the camera distance to frame the chart, not shooting the chart from an identical location. You're seeing the resolution difference, but he's already corrected for the 1.6 crop. So, the very real question of what does the R7 buy you when you're focal length limited, and/or physical position limited, is still an open one. I'll test it. I can even throw on the extender so you'd see what the R8+1.4x vs R7 looks like too. Gotta brush the dogs to get a finely detailed static...

[DavidEccleston]

So, I did one low-light comparison before the subject went away. 300mm 1/400s f/8, ISO 5000, R8 set to 1.6x crop mode (first camera settings page, easy to find). Here's the full image for both, and a 100% crop showing dog nose and fabric detail. Using "preview", and setting to 160%, you can match the R8 and R7 views, and the R7 clearly has the detail advantage, even at an advanced ISO. I used AF, so I can't guarantee the same focus between shots, but should be similar.

I will try to do a lower-ISO version, but likely not today.

I know Flickr puts size limits on non-pros images. I can download the full-sized images, but I have no idea if you can... so I've added crops too. To not clutter up my Flickr, I have them set to private, but accessible via these share links:

R7 - Just exported from LR - https://www.flickr.com/gp/15493374@N03/0e780858C7
R8 - Just exported from LR - https://www.flickr.com/gp/15493374@N03/2qLe240CW9
R7 100% crop - https://www.flickr.com/gp/15493374@N03/yK7rj46Hc0
R8 100% crop - https://www.flickr.com/gp/15493374@N03/A8vA2ZsC63


R7_Dog-100pct by Dave E, on Flickr


R8_Dog-100pct by Dave E, on Flickr