The Apollo detector houses a monolithic active pixel sensor performing correlated double sampling, on-chip thresholding, on-chip event detection, and event encoding. The sensor is composed of 4x2 rectangular sensor segments comprising a contiguous 4096x4096 array of 8-micron pixels. The time resolution for event detection is 418 µs. Pixel readouts from the sensor are directly transferred to on-board field programmable gate arrays (FPGA) that carry out super-resolution centroid mapping, yielding super-resolved dose-fractionated movie frames with 8192x8192 virtual pixels. In these images, each counted electron is converted to a signal value of 16 per pixel. Although the Apollo sensor is capable of a maximum average counting rate of ~266 e -/pix/s, the bandwidth of the on-board memory in the Apollo camera limits the detection rate to a maximum of ~126 million e -/sensor segment/s, which equates to a maximum average counting rate of ~60 e -/pix/s or a total counting rate of >1 billion e -/s. We note that these maximum counting rates are averaged over blocks of pixels and therefore are a straightforward limit during uniform illumination of the sensor. However, in diffraction, the illumination is highly non-uniform, with primary electrons concentrated in discrete reflections. In this case, the detected intensity of each reflection may be much higher than the counting rate limits discussed above, because pixels between reflection will have much lower detection rates. On average, the counting rate limits are still satisfied.