A Common issue/solution is that the wrong scale or position is passed to the solver, causing the solver to spin its wheels looking in the wrong place or at the wrong scale. Thus, often when people have solving issues, unchecking Use Scale and Use Position helps. That said, in @tkakura's screenshots he shows unchecked Use Position and unchecked Use Scale as failing. Note that in his screenshots, the failing positions and scales values are quite different from the successful ones.

@Paul, you should know what your true scale and true approximate position is, so make sure those are about right if you do use Position and Scale, and see if it works. It could be your system was somehow initialized to a bad value. I have definitely seen cases where for whatever reason, the scale is filled in with a wrong scale, and if use-scale is checked, the solver has no hope of succeeding. Also, make sure you're in focus.

A Raspberry Pi 4, being a slower CPU, could use the position and scale to improve response time, but only if they're reasonably accurate.

If things don't work, can you upload (e.g. google drive with a link here) an image you can't solve. That is, capture an image with the same exposure/binning/focus as align uses.

Hy

PS "Blind solves" and non-blind solves aren't really that different. That is, the solvers find star patterns in the test image and then search for those patterns in their data files. So, they all start somewhere. I suppose the difference between a blind and non-blind solve is that in the blind solve, the solver starts at some random place (like RA=0, DEC=0, scale=1) and then continues looking at all possible scales and positions. With non-blind solves the start from the suggested position and scale and searches nearby before looking further away (within the constraints given, e.g. possibly the high/low scales, possibly the search radius, the runtime constraint). In the align module, I believe if you don't check use-position, the solver will start from where the telescope module claims it's pointing (so it's not really "blind").

Read More...