If you plan on taking landscape astrophotography images, you will likely want a full-frame camera. The larger sensors in full-frame cameras generally perform much better than APS-C or Micro Four Thirds cameras, especially when they’re under 30 megapixels. This is because the individual pixels on the sensor are significantly larger and more efficient at collecting light and dispersing thermals, two key factors in helping increase the performance of a sensor. Lenses specifically made for full-frame cameras are also more efficient at gathering light toward that sensor. Wide and ultra-wide angle lenses for full-frame cameras generally deal with distortion and chromatic aberration significantly better than lenses designed for smaller sensors. Going with a full-frame camera and lenses comes at a cost, though, as making the jump to full-frame can be a significant investment.