MAXIM KISELEV

Just a small correction. After experimenting some more, I see I was mistaken. Lowering FOV setting really does help. I eneded up setting my focal length to 850 mm instead of 650 mm nominal, this results in a 0.2 deg FOV. Now ASTAP solves every frame efortlessly both during the session and in post processing. This probably have something to do with my optics. Stars on the outer edges of FOV are not as good as those in the middle. Smaller FOV probably forces ASTAP to limit database sample to only those...

yes, thank you. all this makes sense. cooled camera is definetely on my list of things to buy I did try setting smaller field of view but I found that reducing it below 0.27 also makes it worse. So I think I will leave it 0.27 and set downsampling to 2. Thanks again for helping me with this

I think I have found a workaround for this. If I force x2 binning the plate solves with incorrect 0.28 FOV. Here is the log from three solves, first with 0.27 - solved, second with 0.28-fails. In both cases downsampling was set to 0 and ASTAP decided to bin x3. The last solve was with downsamplig set to 2, and it solved with 0.28 FOV 8:18:55 AM Creating grayscale x 3 binning image for solving or star alignment. 8:18:55 AM 44 stars, 131 quads selected in the image. 80 database stars, 237 database...

as to your point about distortion. This makes sense. If the telescope manufacturer states that focal length is 650 while it is in fact 670, then how can we trust their statement that the mirror is parabolic. It could easily be spherical. Or somewhere in between. If this is the case then I can see how calculated FOV could be off. But still, if I could make ASTAP to prioritize FITS file numbers when solving, some frames could be saved. This is especially important when centering on a difficult target....

Thank you for responding so quickly. here is the image example, this one solves with 0.27 FOV and does not solve with 0.28. I have used D50 database. Stars less than 1.5 were ignored, other settings are all default. https://drive.google.com/file/d/18CW6264xeJ6VF-w05ygWo-C7EMDtAMTo/view?usp=sharing I completely agree, for most images FOV is not critical, ASTAP solves 99% of my images without any problems. I am very much impressed with the speed and accuracy. In this run however, about a half of shots...

my ASTAP version 20260730 has a tendency to overwrite my correct field of view setting 0.27 deg with 0.28 which results in falure to solve my frames. FITS headers in all my files show correct focal length 670 mm, pixels size 1.45 and pixel count 2160. This computes to 0.268, rounded up to 0.27. When I manually enter 0.27 the plates solves efortlessly, but as it does the setting immediately reverts to 0.28, preventing it from solving the next frame (or the same frame). Interestingly enough, the pixel2math...