The LX200 and the Focal Reducer, Part 8 New vs Old

Although the results in Part 7 were indicative, they were perhaps not conclusive that the new lens is worse than the old one. I remembered that the old lens had performed almost perfectly with my ETX125, and that one of the objects I imaged using that combination is in reach now.

In November last year I took a picture of NGC 146, NGC 133, and King 14 as a group with the focal reducer attached to my ETX125. This combination has a number of advantages over the LX200, for example:

The ETX is a Maksutov and as such has no chance of mis-collimation
I can be absolutely sure that the set up is identical now to what it was last time

I can also go into my archives and be sure that the old and new images were processed identically. Each was a stack of 15 frames, each of 30 secondes exposure, stacked in RegiStax with only a tiny wavelet enhancement. The results are below.

	This is the picture from November last year taken with my old focal reducer. Notice the almost complete lack of coma.

	And here is the same region taken on 2nd of July using the new focal reducer. You can clearly see coma on stars near the corners of the picture (look in the lower right). More careful examination shows coma on all stars outside about the innermost 50% of the picture.

Conclusion:
The new lens is significantly worse than the old one. I shall be asking for the old one back.

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