High sensitivity refers to the highest ISO range that a model can withstand. Generally speaking, the larger the value of the highest ISO range, the better the high sensitivity of the model. ISO can effectively increase the shutter speed when the light conditions are poor, thereby ensuring the clarity of handheld shooting.
When the Pentax 645Z is at ISO6400, the picture appears grainy to a certain extent, but the overall noise control is relatively excellent. In addition to better noise control, the preservation of in-focus details is also relatively good, and it is not inferior to 24 million-level full-frame cameras at the same ISO. After the sensitivity is increased to ISO12800, the graininess of the picture becomes more obvious, but the overall usability is still high. Starting from ISO25600, the detail sharpness drops significantly. At ISO102400, the picture usability is relatively low. In general, the Pentax 645Z subverts people's perception that medium-format cameras are only good at shooting at low sensitivities, and the available sensitivities are directly expanded to the ISO6400-12800 range. Excellent image quality under high sensitivity is no longer a patent of full-frame cameras. In other words, the Pentax 645Z has changed the way of shooting with medium-format cameras. Photographers can use higher sensitivity and handheld shooting in dark scenes. .