Is there any hope for this. I put the plate solve in so you could see the sources of the two (there is actually a second duller one in the lower right).
The image is 600s of H-alpha, so you could cut that down, but with the obvious downsides of less signal.
Hopeless? Better brand/type of reducer?
For the record (and Google Search the backfocus from the end of the Celestron Focal Reducer to the front plate of the STT 8300M is 4 inches- 10cm).