45* Erecting Prisms

I posted this in the course of another thread and never got an answer, so I'll try again as a new thread...

Has anyone tried the William Optics erecting prisms? Just curious as to quality vs the other 45* erecting prisms that are available.
http://www.buytelescopes.com/product.asp?t=&pid=4335&m=49
http://www.buytelescopes.com/product.asp?t=&pid=4331&m=49

Jim

Hey Jim,

For what it's worth, I use a Televue Ranger for birding. I've used the TV 90* mirror, an Orion 45*, and the porro straight thru.

1. The first 45* I used produced a glare "line" when I looked at something intensely bright like a planet, but didn't show anything in daylight. I replaced it with a similar one from Orion and don't have the problem anymore. So there's difference between seemingly identical equipment. Mark it up to quality control.

2. I really can't notice any difference in contrast, brightness and sharpness between the 45* and the TV mirror 90*!! I tried. An astronomer friend of mine says you really only see difference at high powers. I've used mine at 60x or more without seeing a diff.

Also, when I have used the mirror diagonal at high power birding, I have a hell of a time finding the bird because of the left-right reversal.

In short, I use my 45* 99 percent of the time.I often share the view, so a 45 works out nice as my partner and I have almost a foot difference in height.

Finally, if i replace it, I would probably go with the one you mentioned just because it looks like it was assembled with some care and quality control is 50 percent of the reason that top brands are worth so much more than bottom brands. $99 isn't that much for something you'll use for years and years.

cheers and good birds to ya!