refractor diagonal comments?

I am looking to purchase a 2" diagonal for a Meade 5" acromat. I have heard good things about the Williams Optics 2" diagonal, but there are two options. Would it be worthwhile to get the one with dielectic coatings? (more$$)

Also, I would like to get some sort of minus-violet filter to keep permanently installed in this diagonal. Are any better than the others? Are there any I should avoid? Any other options I should be considering?

Thanks,
Charlie

I have an AR5 and the color ain't that great on Jupiter and bright stars. I use a minus violet filter for that, Otherwise, no need to.

I'm using a Meade UHTC 2" diagonal I bought here for $100 and it's just fine. I've owned the TeleVues in the past. I don't think most eyes could tell the difference between the 97% and 99% diagonals. This was the subject of much debate a while back on another forum and some said they could tell the difference in the two different TeleVue diagonals - most said they couldn't. But most also went ahead and bought the more expensive ones, too. Go figure.

William Optics makes a 2" Minus Violet filter.

I've seen one on a Megrez 80 with excellent results. Can be had reasonably from Anacortes.

http://www.buytelescopes.com/product_list.asp?m=49&t=48

Regards,

Ron

you need to make sure that the filter uses glass that is flat and uniform to optical standards. Many filters use ordinary float glass and cause image degradation when used away from the focal plane (e.g. on a diagonal). Check the recent S&T article about color correction filters. The only filters they mention as not degrading the image were the Baaders. Elsewhere, Astronomik has been mentioned as making good optical quality filters. Not sure if either of them make a 2" minus violet filter.

David