SM 90 - well done Bill.
What story did you come up with
Is there a reason you are only using a 25mm EP? Also I would think the SM90 on an ED80 will show pretty good views, even at 24x, which is underutilising it and might be a bit bright for good detail. With that setup you should be able to go way beyond 100x if conditions permit. Any eyepiece will work to some degree. None should be total crap. If you see a featureless red disk, there are 4 explanations I can think of, assuming filter set is installed correctly:
1. Likely: Image too bright at low power, see above. Stop down or increase magnification.
2. Likely: Filter is tuned out. Tune by turning the little brass thumb wheel
3. Possible: You may be looking at a ghost image. My SM60 shows ghost images many degrees from the main image (which means they are not a problem because they are not in the same AFOV as the main image). The first thing I saw through mine when I first got it was such a ghost, and I thought ...k me, the filter's a dud
4. Unlilkely: Etalon is broken. Better think of a an even better story before returning the equipment
?
- so interested to look at solar work for a while otherwise I might have to get rid of quite a collection of my gear which has not been used for almost 18 months! I managed to borrow a Coronado SolarMax 90 filter kit recently.
