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Accepting all of the limitations that have been pointed out for the focal reducer with our equipment, we still took the opportunity to try the reducer with the elements in the reverse direction. It took a while to get the weather to co-operate but we finally had an opportunity last Sunday am.
We fully understand that the attached pictures are of very poor quality with many issues but they do seem to indicated that the problem with the reducer has been mitigated to some degree. The picture of Southern Pleiades is a single exposure taken on 6/5 with the 0.5 reducer in its original configuration which shows the "headlight" effect on the stars. The picture of the Butterfly Cluster was taken on 26/5 with the elements reversed in the reducer. It is a stack of 15 subs at 4 sec exposures and even though we still have significant issues to fix, the "headlights" and flaring appear to have gone.
We understand that the stars are not round, our biggest issue with this is movement caused by our DIY tracking platform which is limiting exposure time (working on this). Even at 4 secs there was really no usable exposure. Also attached is an image of the moon taken on the same occasion as the Butterfly Cluster, using the reducer which also appear to have worked reasonably well. Once again this is with the elements reversed. Without the reducer we cannot fit the moon in a single image.
We can now achieve focus using the reducer and it is at least suitable for our standard of imaging.
Peter & Clare
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