What is Deep-Sky Astrophotography?

My Profile on Astrobin: https://www.astrobin.com/users/WilliamGott/ Starburst Galaxy (Taken by the President of our Astronomical Society) - Astrobin https://www.astrobin.com/gek830/ Astrophotography - Wikipedia https://en.wikipedia.org/wiki/Astrophotography Milky Way Image (a Shot I Took) - Astrobin https://www.astrobin.com/be7t7j/ Apochromatic Lens - Wikipedia https://en.wikipedia.org/wiki/Apochromat Bino-Refractor that is $27,310 - Deep Space Products https://www.deepspaceproducts.com/product/cff-bino-refractor-160mm-oil-spaced-triplet-apochromat?gclid=CjwKCAjw1JeJBhB9EiwAV612y4Uq1I-9Q1J7o6-K9mAJFySwplVHqsM1z1FI7PLxqDb3_YqAuTLUbxoC0I4QAvD_BwE Field Flattener - Night Sky Pix https://nightskypix.com/what-does-a-field-flattener-do/ Petzval Lens - Wikipedia https://en.wikipedia.org/wiki/Petzval_lens Newtonian Reflector - Wikipedia https://en.wikipedia.org/wiki/Newtonian_telescope Dolphin Nebula (Diffraction Spikes are Present on Stars) - Astrobin https://www.astrobin.com/zihlpc/ Schmidt-Cassegrain Telescope - Wikipedia https://en.wikipedia.org/wiki/Schmidt%E2%80%93Cassegrain_telescope Telescope Pier - OPT Telescopes https://optcorp.com/collections/telescope-piers Planetarium Software - Wikipedia https://en.wikipedia.org/wiki/Planetarium_software