Mirage - Normal Glass vs ED Spotting Scope

[AR Shooter]

ED (or HD) is better glass. Especially in lower light conditions. You'll likely never notice the difference until you do and you'll be glad you have ED glass. As stated above, get the best you can afford (says the user of a Kowa Prominar spotting scope - ED glass & all ED glass scopes).

A good quality spotting scope is a "lifetime" product (you'll own it forever). Get a good one.

 

[Turbulent Turtle]

ED (or HD) is better glass. Especially in lower light conditions. You'll likely never notice the difference until you do and you'll be glad you have ED glass. As stated above, get the best you can afford (says the user of a Kowa Prominar spotting scope - ED glass & all ED glass scopes).

A good quality spotting scope is a "lifetime" product (you'll own it forever). Get a good one.

Please note that HD glass is not the same as ED glass, for the purposes of this discussion.
HD glass is "High Definition" or "High Density" glass, and does not address chromatic aberration. ED (and Super ED) glass, is where ED means Extra low Dispersion.

I have found that when manufacturers really use ED glass, they will state that fact in their propaganda. March is the only one using Super ED. Their propaganda states all their other scopes use ED glass, except for the LPVOs, where ED glass is not needed.

Edited to add: ED is not necessarily "better glass". It is designed to address a specific issue (CA) and it's only a few lenses that are ED and Super ED glass. Super ED glass is very spendy ($$$).

 

[209jones]

I don't understand a pile of optics discussions, but, I can say that along about 1991, I had a double hole on a target I couldn't see at 200yds with a 15-45 B&L spotter, so, got mad and went to sa birding/optic store, end up with a Kowa 77. Took the target with me and stuck on a post 200 yds away (turned out to be quite conveniently on the entrance to Cdn Tire store) across the mall lot. Hot day, lots of mirage, it was pretty much no contest against 5 or 6 other spotters he had there. Seems to me it has flourite coated lenses, and that's always been an ad feature with Kowa since then, at least. Not that I intend to "upgrade" it, but do wonder what would be the difference in the lenses, from say the 1991 flourite coated lense to what is on them now? I have certainly never regretted buying that scope, although it was a case of handing him the c/card and saying "don't tell me the price" at the time (was 1000.00 Cdn).

 

[Turbulent Turtle]

The word is fluorite, not flourite. Also, fluorite glass is not a coating, it's the actual glass material. There are fluoride coatings, but that's not what we are talking about here. Notice the spelling: fluorite glass, fluoride coatings. Not the same thing.

Not sure about the Kowa 77 from 1991, but I think Kowa introduced their fluorite glass more recently and the 77 was XD glass until recently. I think that's their version of ED or even Super-ED glass.

 

[Krogen]

Some years ago an "eye-opener" to better sporting optics occurred while hunting rockchucks. I had a new set of Fujinon binoculars. I spotted a critter flattened out sunning itself on some basalt. Plain as day. Then I went to find him in my Leupold scope. I couldn't see him. Back to the binoculars and again he was plain as day. I still couldn't find him in my scope. The hapless critter lived another day.

I think this was largely due to binocular vision. Two eyes are better than one! Still, closing one eye and looking through the binocular gave a better image than the scope. That points out the second issue - optical quality. Fujinon lenses and optical mechanism were just better than Leupold.

 

[Turbulent Turtle]

This video might be of interest for the readers of this thread.