If you're just starting out in the hobby of deep sky imaging with a DSLR or Mirrorless camera, we recommend starting with a light pollution filter if you live under light polluted skies. These filters will allow you to cut out some (not all) of the light pollution to capture objects like galaxies from home. If you're using a full-spectrum astronomy camera, a multi-bandpass filter is hard to beat for imaging targets like emission nebulae.