Sony A7R IV has a
61.0MP Full frame (35.8 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz X processor. On the other hand, Sony A7R VI has a
67.0MP Full frame (35.8 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz XR processor.
Sony A7R VI's sensor provides 6MP more than Sony A7R IV's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Another similarity between these two cameras is that both Sony A7R VI and Sony A7R IV sensors lack anti-alias (Low-Pass) filters. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the A7R IV and A7R VI sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A7R IV and Sony A7R VI Cameras
Sony A7R IV and Sony A7R VI have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Sony A7R IV has 11% larger pixel area compared to Sony A7R VI, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Sony A7R IV and Sony A7R VI sensors have been tested by DxO and the results show that A7R VI has a better overall score of 100, 1 points higher compared to A7R IV's score of 99.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A7R IV
99
26.0 bits
14.8 Evs
3344 ISO
Sony A7R VI
100
26.1 bits
14.8 Evs
3187 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony A7R IV
or the
Sony A7R VI ,
including hyperfocal distance.