Dave, Glad to have provided you with an outlet for your "unique" point of view. Is there any possibility of you posting a link of some kind to some of the library's more interesting treasure trove? When the society was resurrected in 2004, I thought it might be more tongue in cheek this time around - sounds- not so much lol Mat Chuck has already posted his thoughts on the horsehead filter issue I would like to add from a different point of view (odd little pun there) reminding ever yone that the horsehead is backlit. The stars behind it are relatively young and could be putting out more energy across the EMS, including t he 03 band. Then again, you also said the stars were twinkling - so maybe it was more atmospheric scatter on the earth end. Maybe a combination of both. It's been years since I saw the horsehead in Lowell's 20 inch and I think he had an O3 filter in then. Wish I could remember the details. I was just excited to see it. Congrats on scoring the horsehead which is, allegedly, a photographic only object.