Comments on Why do these photometric observations of Betelgeuse look “quantized” in 0.1 magnitude steps? suggest that these are visual estimates, mostly (but not all) to 0.1 magnitude resolution.
Are there any designs for simple photodiode-based amateur photometers for stellar brightness measurements?
Just as an illustration of the kind of thing I'm asking about, I'm imagining a pair of binoculars with a 1 mm photodiode suspended by its wires the focal plane of one eyepiece, and a Raspberry Pi recording the photocurrent (with a small amplifier) and audio simultaneously ("I'm now measuring xxx... mark!") The data would be jumpy but presumably would reach a plateau whenever the star fell on the active area of the diode.
Or is this too impractical and not backwards-compatible with existing data?