pentax sdhf 75 apo startest

hello
this is my first post in this wondefull community.
i Buy this refractor last week and in a night of good seeing i decided to test it and when i got the startest i got this result
i never seen about a refractor a result like this
the test was done whit a DSRL Nikon D 70 without barlow and without diagonal,the star for the test was Vega but also whit stars of small magnitude didn't show difference
what the result show is what i see clearly also in visually test whit a baader genuine ortho 5 mm .This big (too big)spot in the centric in intra and extrafocal are normal? i think, but im not so expert, who is a big zonal error
sorry for my bad english
thanks in advance for yours comments
cheers
Giorgio

Attached Image:

Yes, you would seem to have a zone at the center of the lens.
The error is large in terms of wavefront wavelengths, but is very
small in terms of the area affected. It will be a little like
a Newtonian with a small secondary mirror. The rest of the lens
looks OK. Overall I would say it is probably a good lens.
The peak-to-valley error will be large, but the root-mean-square
error and Strehl ratio are probably OK.

There are no other optics -- only the Pentax lens?

If you know the amount of defocus in mm for the outer
images (on left and right) it might be possible to calculate
the errors. Was the image re-binned or re-sized?