After considering my mount as part of my lightweight re-think of my astrophotography setup, I need to consider my optical and imaging setup. Currently I use an Orion ED80 f/7.5 refractor. The ED80 has a focal length of 600mm, and weighs 2.6kg. To this I add a 0.85 focal reducer/corrector that adds 320g and reduces the focal length to 510mm.