Data from different nights can have significantly different throughput, so weighting by exposure time is not optimal for obtaining the best signal to noise. Design a weight calculation by comparing to stars across the image and deriving an initial zero point. This will require running photometry on each frame before the image stacking step.
Data from different nights can have significantly different throughput, so weighting by exposure time is not optimal for obtaining the best signal to noise. Design a weight calculation by comparing to stars across the image and deriving an initial zero point. This will require running photometry on each frame before the image stacking step.