Measured ISO and dynamic range comparison

Fotoni said:

DxOMark say that D3200 ISO 100 is measured as ISO 71 and dynamic range is 13.23 EV

DxOMark say that K-1 ISO 100 is measured as ISO 95 and dynamic range is 14.6 EV

https://www.dxomark.com/Cameras/Compare/Side-by-side/Pentax-K-1-versus-Nikon-D3200___1075_801

Does this mean that Pentax K-1 actually needs less exposure at ISO 100 setting than D3200, but still has 1.37 EV advantage in dynamic range?

Click to expand...

Sure, the K-1 has 2.34x more sensor area, so it gets 2.34x more light at the same exposure. This also means it captures a different image, so I don't compare different sensor sizes at the same exposure. I compare them capturing the same image.

Optically shrinking an image to APS-C from full-frame makes it 2.34x brighter. The D3200 ISO is effectively 2.34x the K-1 full-frame ISO. The base ISO of 72 on the D3200 acts like 72x2.34 = ISO 169 on the K-1. Theoretically an APS-C sensor with a base ISO of 95/2.34=40 ISO could be expected to match the performance of the K-1.

The D7200 already seems to have better dynamic range at base ISO than many full-frame cameras even without such low base ISO. It is actually full-frame and larger cameras that don't reach the dynamic range we might expect.

If you take a few frames with your D3200 and combine them in post you can match the dynamic range of the K-1 at base ISO. You effectively halve your base ISO by combining 2 frames and double the dynamic range.