OM System OM-1 has a
20.0MP Four Thirds (17.4 x 13 mm ) sized Stacked BSI Live MOS Sensor sensor . On the other hand, Panasonic GH7 has a
25.0MP Four Thirds (17.3 x 13 mm ) sized BSI CMOS sensor .
Panasonic GH7's sensor provides 5MP more than OM System OM-1'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 Panasonic GH7 and OM System OM-1 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 OM-1 and GH7 sensor size comparison.
Sensor Size and Resolution Comparison image of OM System OM-1 and Panasonic GH7 Cameras
OM System OM-1 and Panasonic GH7 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
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
OM System OM-1
or the
Panasonic GH7 ,
including hyperfocal distance.
