Eta Carinae

[Karlzburg]

I tried Eta Car again with the reducer off to see what difference it would make. I know the resolution doubles with it off as far as what APT tells me when I do the calcs.

12 x 600sec
ISO 200
Darks
no Bias or flats

[mental4astro]

Hi Karl,

Looking at each of your pics, I woulld say that the focal reducer you are using is introducing astigmatism and spherical aberration. The tell-tale sign of astigmatism is those little seagulls that are co-centric to the optical axis. The spherical aberration comes from the comet-like appearance of the stars - it's not coma here. Coma has a similar appearance, but it's not what is being seen.

Alex.

[xelasnave]

However a great effort Karl given the quipment issues.
Alex