A preferred method for transmission electron microscopy includes a step of generating a microscopy signal. The microscopy signal is then detected with an active pixel detector that includes a plurality of pixels. Each of the pixels includes at least one photodiode. Each pixel integrates an incident signal over a collection time period. Using a massively parallel on chip analog to digital conversion, very fast read out times can be achieved, e.g., many frames per second. In a preferred embodiment, the read out time permits there to be a single electron event recorded per pixel, indicating either a single electron or the lack thereof. This permits simple accumulation of the pixel counts for each pixel in read-out and storage electronics.