Jupiter - Digital zoom and stacking?
I thought I would try scaling images before stacking them to see if the result was better than not scaling. This is effectively the same as using digital zoom where the greater image size is due to interpolation between the pixels. For a single image no new information is gained with digital zoom, so there's no point. However when stacking, the increased number of pixels gives scope for finer adjustments in position for aligning and presumably subtle tone variations, even in the interpolated pixels when stacked, may provide more information.....well that's what I wanted to test. I tried this for Jupiter stacking 37 images in Registax:
Stacked image, no resizing before stacking, upsized final image by 150%:
Stacked image, where they were upsized to 300% before stacking and the final image reduced to 150% after stacking to match the image size above:
I know there's slightly different post processing, but each was done to maximise the detail shown. To my eyes the 2nd image seems to show more detail and therefore suggests there is an advantage to upsizing images before stacking. But there could be another explanation. If Registax can align between pixels anyway, then presumably there wouldn't be an advantage of up-sizing before stacking? Interested to hear others views, maybe it's a tried and tested technique anyway?