Hi Dave,
Great shots for such short exposures!
looks like we have about the same level of light pollution.
Since I moved to Auckland it got a lot better with light pollution for me. I can see the LMC and SMC in good nights with direct vision and the Milky Way almost always unless it´s too far down in Auckers skyglow (which is cute compared to Melbourne´s
).
However, I am still using the Astronomik CLS clip-in filter for my EOS and with it I can easily expose 5-10min (ISO 800 - depending on direction, elevation) whilst maintaining a histogram with the skyfog peak within the first third (left of center).
Keep the ISO down as it doesn´t create more image info (photon´s) it just amplifies the few you collect over time as well as the noise.
What focal lenght is your refractor? Your Jupiter looks awesome, I thought planets taken with SLR on prime wouldn´t be much of sight unless one deploys 5m focal lenght.
Cheers