Orion Nebula (South Australia)

This is my first Image I've uploaded onto this site of the Orion Nebula. I'm still very new at this and believe my telescope is slightly out of Alingment which i plan to fix over the next few days. I've taken a few other images of the Orion Nebula before but the middle has always been over exposed, this is my first attempt to fix that problem.

This image consists of 4 photographs at various ISO and Exposures stacked with a total exposure time of 21 minutes.

It's taken with a Celestron HD 8" SCT on a Celestron Advanced VX Mount and a Orion SSAG + Short Tube Guiding setup. I've ordered myself a focal reducer so I hope that will arrive in the next week or two.