Quote:
Originally Posted by Leonardo70
The metal backfocus of standard reducer is 72.2mm and remember to calculate the extra coming form a filters tickness.
An exposure of 30min with 8300 is a light bomb ... you need a superdark sky to avoid gradient.. but probably you have this. 
Again congrats Paul...
All the best,
Leo |
Thanks for the correction Leonardo regarding the metal back distance. My filters give me another mm to work with. That said for now I am not going to be buying the CAA and a Takometer.
1 hour out of Adelaide generally is a quite dark sky. So 30 minute subs are ok. Most nights we get around 21.6 on an SQM. There is some slight light pollution to the north west of my position but I don't image in that area much.