Sigma FP2 is more than twice as fast as predecessor

As a full-time e-shutter camera, the Sigma FP’s rolling shutter rate is critical for its usability for stills as well as video. We’ve carefully measured the camera in a series of modes, to check the impact on both.

The camera’s max sync speed of 1/50 sec already gives a good hint of how quickly its sensor can read out. Sync speed is defined by the shortest period for which the entire sensor can receive light from the flash. It’s defined by how quickly your shutters can start and end the exposure, because you need a delay after the bottom of the sensor’s exposure starts but before the exposure ends for the top of the sensor.

In a typical e-shutter system, exposure is ended by reading out the sensor, line-by-line. If it takes 1/60 sec to read out the whole height of the sensor, then the process of ending the exposure has to begin 1/60 sec before you want the exposure to end for the bottom of the sensor. So the shortest exposure where the whole height of the sensor is active and able to receive light from the flash is a fraction less than 1/60 sec.

Stills mode:

Our tests show that the FP2 takes 14.2ms (around 1/70 sec) to read out its sensor in single-shot mode, regardless of whether you’re shooting JPEGs, DNGs or both. This is a tiny fraction faster than we saw on the Panasonic S1II or Nikon Z6III. Interestingly, the Nikon is able to sync with flash up to 1/60 sec, rather than the 1/50 sec limit of the FP2, which makes us wonder whether Sigma is less confident about how precisely it can trigger the flash to fire, during that tiny period during which exposure has started for the whole sensor, but not yet begun to end.

In the camera’s burst modes, the rolling shutter rate jumps to 11.1ms (~1/89 sec). This suggests the FP2 could sync at a faster speed if pushed into this readout mode when you connect a flash.

Video modes:

We also checked the rolling shutter rates in video and found them to be entirely consistent with this faster mode.

We measured the readout rate for both the 6K and 4K open gate modes and found them to be the same in 6K/30 as at 4K/60 and 4K/30. We also found the 6K open gate Raw output matched this 11.1ms rate. This suggests the 4K open gate footage is derived from the 6K capture, which implies the sensor can be read fast enough for 6K/60 open gate, but that it’s not feasible, for reasons of power consumption, heat generation or processor load, to capture it.

Dropping to the 16:9 modes, the FP2 consistently delivers a 9.4ms readout time, whether you shoot 6K or 4K, 60p or 30p, compressed, processed footage or Raw. 9.4ms for the 16:9 region of the sensor equates to exactly the same 11.1ms for the whole sensor height. It’s the exact same speed we measured when we tested the Nikon ZR.

This is more than twice the speed we saw from the original fp or BF, meaning a subject would need to be moving twice as fast before you experienced a comparable level of motion distortion in your video or stills. It also means the still images should be less prone to banding under artificial lights, as well as being able to sync with flash at exposures nearly a stop faster.

And it’s worth noting we haven’t encountered much in the way of banding during our shooting, so far. This is something we’ll keep looking for, as we keep using the camera.