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ED binos ... a real difference?

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#1 NHRob

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Posted 30 January 2019 - 07:05 AM

I was wondering how apparent the difference is in optical performance going with ED binos?

 

So far, I've only tried Nikon Monarch 5 ED in a store against a Viper Diamondback, both 8x42.

 

To be honest, I could not see much difference.  However, this was about 10 minutes of use in a store looking out windows, etc.

 

Opinions?



#2 TOMDEY

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Posted 30 January 2019 - 08:04 AM

My experience is the APM 100mm. The ED APO are WAY better... and cost a lot more... but still a bargain!    Tom


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#3 Jon Isaacs

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Posted 30 January 2019 - 08:48 AM

My experience is the APM 100mm. The ED APO are WAY better... and cost a lot more... but still a bargain!    Tom

 

How much chromatic aberration do you see at 20x = 5 mm exit pupil in the achromats ?

 

The 8 x 42s Rob was testing have a "chromatic ratio" of about 2.4. With a 5 mm exit pupil,  false color should be minimal. 

 

Jon


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#4 Astroman007

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Posted 30 January 2019 - 11:31 AM

An interesting topic! I was wondering this myself. popcorn.gif



#5 Rich V.

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Posted 30 January 2019 - 11:33 AM

It really depends on what your're looking at.  I don't see any appreciable amount of CA in smaller aperture low mag 6-10x binos during any kinds of use. 

 

At 16x70, though, CA can be quite noticeable during daytime use and when looking at bright objects like the Moon and planets.  On starfields, though, the difference between an achromat and an ED apo isn't particularly noticeable at all.

 

Increasing magnification makes the chromatic fringes and blur easier to see so IMO, ED glass is a useful addition for the bigger, higher mag binos and BTs.  By the time you get to 50x in a 100mm achro BT, even brighter stars can show false color and the difference between an ED design and a plain achromat becomes easy to see.  

 

The focal length comes into play as well; when I compare views through a 100mm f5 achro BT and a 100mm f 7.5 achro there is clearly less CA seen in the longer BT.  A 100mm f5.5 ED doublet shows less CA than the 100mm f7.5 achromat.  Even among ED designs, focal length makes a noticeable difference.  Despite its higher mag, my WO 22x70 ED f6 shows less CA on the same targets than my APM 16x70 ED f4.  Both use similar ED glass; the WO uses FPL-51 and the APM uses FK61.

 

Rich


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#6 SMark

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Posted 30 January 2019 - 12:24 PM

How much does CA bother you? On low magnification night sky targets, it's pretty much a non-issue with me. I did let go of my non-ED Semi-APO APM 100 in favor of an ED-APO version. But only because planetary (high magnification) targets were much improved. CA doesn't cause me to frown on stellar and deep sky targets at all. From what I recall, most tests for CA on low magnification binoculars consisted of targets most people wouldn't normally look at anyway.


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#7 NHRob

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Posted 30 January 2019 - 01:03 PM

CA doesnt bother me,especially at these low mags. Are there other tangible benefits besides CA control?

#8 TOMDEY

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Posted 30 January 2019 - 02:28 PM

How much chromatic aberration do you see at 20x = 5 mm exit pupil in the achromats ?

The 8 x 42s Rob was testing have a "chromatic ratio" of about 2.4. With a 5 mm exit pupil,  false color should be minimal. 

Jon

Hi, Jon! I didn’t actually measure it... but recall that I found the non-apo very rainbowish, unsatisfactory and not even good resolution. But the ED APOs I find to be adequate, even nice... at both low and mid powers. Presents as residual green vs magenta at edges, as a function of focus. The ED (all brands) still show color that is marginally annoying on stuff like tree twigs silhouetted against bright sky (aka pretty severe test). The only binos that I have kept (in smaller sizes, up to 60mm) are all Zeiss... and those are all great, in all respects.

 

Even though I have a lot of binos, I'm a catoptric snob... All-reflective, entirely/identically free of color. So, whenever I use any refractor... I really notice the chromatics. Nother affective is probably that I got my eye fixed, so I can see vivid blues and even electric violets, like when I was a kid, and a hint of near UV. That's a good thing, but really makes chromatic aberrations pop!    Tom



#9 Binojunky

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Posted 30 January 2019 - 03:27 PM

I have owned and looked through a great many binoculars over the years,ED glass can be and is in some cases overblown, it and any other glass thats touted as super duper is only part of the sum of a good binocular.  In smaller size binoculars say 8-10x42,s the difference may not be that clearly seen between a non ED and a ED instrument. In fact I have bought and returned for a refund several ED versions that performed worse than non ED ones. Binoculars are like cars, touted as the latest and greatest with minor upgrades every few years that in practical terms can mean very little,D.


Edited by Binojunky, 31 January 2019 - 12:32 PM.

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#10 hallelujah

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Posted 30 January 2019 - 03:39 PM

In fact I have bought and returned for a refund several ED versions that performed worse than non ED ones. Binoculars are like cars, touted as the latest and greatest with minor upgrades every few years that in practical

terms can mean very little,D.

Dave, you need to try a Nikon EDG. grin.gif

 

https://imaging.niko...42edg/index.htm

 

Stan


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#11 Corona Non Grata

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Posted 30 January 2019 - 04:14 PM

It depends on the utilization. Marketing loves to grab buzzwords. What is to stop someone from using only a small ED element in the eyepices and slapping the label on the model? Scruples, that's all, and those vary in value. WE are the ones who need to ensure its an ED objective if we are to believe it does what we expect.

 

We know the gospel that Bk7 prisms are to be avoided like typhoid (especially if you ignore the exceptions nobody talks about) but how many buyers know the very same Bk7 glass might make a perfectly good, even exceptional, objective lens?

 

We could use more transparency as well as context when it comes to buzzwords.


Edited by Corona Non Grata, 30 January 2019 - 04:15 PM.

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#12 Pinac

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Posted 30 January 2019 - 04:22 PM

I was wondering how apparent the difference is in optical performance going with ED binos?

 

.....

.....

.....

The best way to test the difference is by using models for which both versions exist, a non-ED versions and an ED one.

 

This is e.g. the case with a number of the Lunt / APM binoculars, specifically

 

- Lunt / APM 7x50

- Lunt / APM10x50

- Lunt / APM 20x70

- APM 16x80

- APM 20x80

 

etc.

 

In my experience, the difference is immediately recognizable (the ED versions have better contrast, less CA, and a higher color fidelity).

This doesn‘t mean that the non-ED versions are useless or bad. The ED versions are just a bit better (and more expensive).

 

Just my 2 ct.

Pinac


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#13 rockethead26

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Posted 30 January 2019 - 06:36 PM

How much does CA bother you? On low magnification night sky targets, it's pretty much a non-issue with me. I did let go of my non-ED Semi-APO APM 100 in favor of an ED-APO version. But only because planetary (high magnification) targets were much improved. CA doesn't cause me to frown on stellar and deep sky targets at all. From what I recall, most tests for CA on low magnification binoculars consisted of targets most people wouldn't normally look at anyway.

I agree with this. I didn't buy my APM 100 semi-apo bino for use on planets, the Moon or on bright stars. I bought them for everything else. I have a 120ED telescope for those objects. I couldn't justify the extra price of the Apo version for my intended use. The semi-apo throws up fine images of the Milky Way, star clusters, nebula  and larger globs. I've never wished that I had spent the extra $$ on the apo version.


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