|
From what I read about fast ED doublets. That's about right. The TMB version of 92mm f5.5 is a triplet with a FPL-53 glass element, and every owner describes it as near perfect color correction. I seriously doubt the LP even has a FPL-51 element and has another type that's an equivalent that is almost as good.
A ED doublet "APO" at F5.5 will need to be impossibly well made to give near color free images. Just because it says ED APO doesn't mean it is.
I found that scope on Lee Andrew's website.
"ED APO 90mm f/5.5 doublet achromatic refractor"
Even he can't decide if its an APO or achromat.
No doubt however, I bet that telescope is fantastic at rich field observing. But, I would never put a camera to a ED Doublet that fast.
Get a SW ED80 instead. It has a FPL53 Element and long history of its quality and color correction. A SW ED Doublet will be my next scope purchase in fact.
|