Even if you take two cameras with a similar pixel density, such as the E-M5 ii and A7rIV, so that each pixel more or less receives the same amount of light, the sensor still receives more light in total, so still has a similar equivalence due to size difference. You might look at it at 100% and say they’re the same at the same ISO, but it’s not the case when you look at the images at the same size, like you would when someone is looking at a whole photo. The roughly 2 stop advantage still comes in play because the sensor as a whole receives more light despite each pixel getting a similar amount of light as the smaller sensor. Hence, f/4.5 is still equivalent to f/9, maybe slightly less but close enough, you would effectively get the same results just more detailed.
Hence the post
>>3764914 is wrong. A FF lens at f/9 projects the same amount of light as f/4.5 lens in MFT, it is just spreading it out over a larger circle at a lower intensity.
50mm f/2 and 100mm f/4 both have the same 25mm aperture.
