Thread: ED glass in Scopes & Binos

I've just bought a new scope that was heavily discounted.
It is the Vanguard Endeavor RS IV 5-20X50 that apparently comes with "Premium HOYA ED Glass which provides True Color and Edge to Edge Clarity" (so the marketing hype goes).

So as far as I know in scopes and binoculars, there are 'standard glass' lenses, 'HD' lenses, and 'ED' lenses. Also if all lenses are Fully Multi-coated, then ED is better for image quality than HD which is better again than a standard lens (although some manufacturers seem to use 'HD/ED' interchangeably??).

A 'better quality of image' from ED glass, seems to mean that light dispersion or 'spread' is reduced in the scope or bino, so that fringes of color around the image (known as color fringing) are reduced/minimized.

ED glass is said to control and minimize this dispersion by concentrating and directing the wavelength of light (more effectively than HD or standard lens), towards your eyes. Generally speaking, the better these colour aberrations are controlled, the cleaner and sharper the image will appear.

But you know what?
I can't see/tell any difference with this ED glass Vanguard vs my Sightron & Bushnell Elite HD glass scopes (I know different manufacturers/models but that's what I have to compare - Micky Duck will say I'm comparing 'apples and oranges').

And another thing....this ED glass in the Vanguard scope definitely does not enhance brightness… it just doesn’t have any significant low light advantage.
There is also a natural lack of chromatic aberration seen in low light environments so ED glass in low light doesn’t have any benefit over HD glass. One just cannot see chromatic aberration in low light/the dark… so no need for ED glass.

So to sum up....one of the things that has long bothered me is the VALUE - to the average shooter - of “ED” glass. From where I stand, ED glass, particularly as you move towards lower powered scopes & binoculars (say 16x and under), is more hype than substance.

I really can’t see a purpose strong enough to justify the cost difference (which is significant), between scopes and binos with ED vs HD glass.

I want to say it is so much smoke, mirrors, and marketing.
But, some on this forum speak so highly of THEIR ED glass scope or binoculars, that I don’t want to - unduly - rain on anyone’s parade...

well I need not comment........LOL.

That's why you need to make sure when you buying binos that the end with "el"

HD and ED as far as optics go are just generic marketing terms that anyone can slap on their optics.

Also nothing 'enhances brightness'. That would break the laws of physics. You could impede brightness less than other optics, but you cannot enhance it.

HD in glass is supposed to mean High density. glass that is of high density has lower refraction, yoi basically get a sharper image. But since the advent hd tv, which means high definition, a lot of acopes uses this term without necesaarily using high density glass.

ed has always had a specifc meaning , extra low dispersion, usually ed glass is used to correct ca. But on cheap scopes, when all other pieces, of glass are of low quality, having a ed lens cannot save it from being bad.

Find a specification for extra low dispersion though, the terms are meaningless unless there is data to correlate back to the quality - and that should be presented in the scope specifications.

Originally Posted by vulcannz

Find a specification for extra low dispersion though, the terms are meaningless unless there is data to correlate back to the quality - and that should be presented in the scope specifications.

There are not specifications for ED glasses as far as I am aware. And no doubt not all ED are created equal. However, the term ED has been around long enough, and ED glass is different to normal glass enough that when a manufacture claims its lens/scope/binos have ED glass, it will probably have it. No self-respecting brand would falsely claim otherwise. They know they cannot get away with calling their scopes "HD" - which they can just claim to mean High Def, i.e. better resolution than the last gen.

But the most important thing is that if a scope has a ED glass but also loads of sub-par glass, the result would be visibly bad. This is the thing - optical quality tend to be quite transparent. the view speaks for itself.

There are other advertises claims that are not specific or cannot be definitive either, for example a lot of scopes advertise to have "multi-coated" lens. But how many coats, what coating, and which piece(s) of glass are coated - they do not say either.

Originally Posted by Ultimitsu

They know they cannot get away with calling their scopes "HD" - which they can just claim to mean High Def, i.e. better resolution than the last gen.

Reminds me of when I was in Asia and there was a baby milk formula that stated:
"Scientifically proven to improve your babies IQ"
...and had a photo of a baby with a university cap and degree.



Then in small letters right at the bottom, it read" "IQ is 'Intestinal Quality' "

Originally Posted by Ultimitsu

HD in glass is supposed to mean High density. glass that is of high density has lower refraction, yoi basically get a sharper image. But since the advent hd tv, which means high definition, a lot of acopes uses this term without necesaarily using high density glass.

ed has always had a specifc meaning , extra low dispersion, usually ed glass is used to correct ca. But on cheap scopes, when all other pieces, of glass are of low quality, having a ed lens cannot save it from being bad.

I always thought that 'HD' meant high definition glass, not high density. It was Vortex which termed 'HD' as high-density glass which is simply a Vortex marketing gimmick.
Consumers have already been conditioned to associate the term HD with excellent picture quality as we see in high-definition TVs, so that's why it’s being attached to binoculars.

As has been said, not everyone's "ED," "HD," "XD," etc. is created equal, and there are no industry standards for defining what exactly makes any particular optic an "HD" or "ED" model, nor what performance level the optic must achieve before it can be so labeled.
About the only thing the consumer can go by is the so-called ED / HD optics are usually optically superior to the non-ED/non-HD versions from the same brand... but even then not always by a significant degree.

Summary: It's mostly marketing hype.

And the stupid thing is that consumers will often judge some goods by price perception rather than facts (i.e. where a higher price implies quality).

At least with optics , as mentioned , you can just look through them and judge the optical quality and compare by looking through other scopes next to it on the shelf .
Try before you buy ....??

Originally Posted by Ftx325

At least with optics , as mentioned , you can just look through them and judge the optical quality and compare by looking through other scopes next to it on the shelf .
Try before you buy ....??

Uh huh, how many shops over here stock a full range of brands and models, and let you inspect these outside?

I'd wager the majority of scopes are bought unseen, and unfortunately modern consumerism encourages perceived value and that in turn drives the marketing behaviour that brings us stuff like "HD".

Brightness as a term for scopes and binoculars isn't scientific but somewhat subjective. It is dependent on materials and design of the optic.
Bigger lenses enhance perceived brightness by increasing the light gathering ability of the optic. Transmissivity is the measure of how much light makes it through from front lens to eyeball. That varies greatly between manufacturers, and is affected by glass quality, the number of lenses and prisms that the light has to go through, and coatings on the glass surfaces as with everything, it's a compromise between how much money you have to spend, and how much performance you really need, and the marketers will always try and sell you a cheap product dressed in expensive sounding terms!