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First Look at EDG 7x42 (1 Viewer)

henry link

Well-known member
I had the opportunity to briefly test a prototype of the new Nikon 7x42 EDG binocular today. I didn't have time to be as careful as I would have liked and used abbreviated versions of my usual tests which included resolution and artificial star testing at boosted magnification of 56x and examination of a CA target for longitudinal CA at 56x and lateral CA at 7x. I was able to very briefly compare the EDG to a Zeiss 7x42 FL, a Leica 8x42 Ultravid (non HD) and a Nikon 8x42 LX L, looking mainly for differences in brightness, contrast and color transmission.

After just a few minutes it was clear that the EDG has MUCH higher light transmission than the LX L, and, I believe, slightly better contrast and a little more neutral color (there's just a slight hint of the usual Nikon red). Light transmission in the LX L series really needed improvement and the difference is quite obvious. The EDG appeared to be just slightly dimmer than the Zeiss FL and just a bit brighter than the Ultravid. The EDG is probably about as bright as current technology allows a complex binocular with a Schmidt-Pechan prism to be.

An artificial star test at 56x (Christmas tree ornament in sunlight) revealed a little misalignment in the left barrel (probably a side effect of collimation and pretty harmless). The right barrel was completely free of assembly defects, with just the expected aberrations. It was not the very best looking star test I've seen from a binocular, but, by binocular standards there was nothing seriously wrong either. Resolution was perfectly fine, around 3.5 arcsec in the right barrel, about what I would expect from a typical premium 42mm binocular and much better than is needed for a sharp image at 7x.

Longitudinal CA, viewed at 56x, was clearly better than the LX L. The purple fringe on the the CA target was reduced to about 1/4 the width of the fringe seen in the LX L, very similar to the Zeiss FL. The low CA makes the 56x image look quite clean and contrasty compared to most binoculars, again similar to the Zeiss FL. IMO, lateral color (the type of CA you actually see as a color fringe in binoculars at low power) is pretty bad in the LX L series and it appears to be improved in the EDG to about the level of the Zeiss FL, but all the high end roof prism binoculars have more lateral color than just about any garden variety Porro with a simple doublet objective.

There appears to me to be very little rectilinear distortion in the EDG, a design approach similar to the SE series. That's in contrast to the Zeiss FL and Leica Ultravid which employ considerable pincushion with the goal of the eliminating the "rolling ball" effect when panning. Unfortunately I didn't have time for a careful evaluation of off axis sharpness, but my brief impression was positive. I think the EDG probably uses a low astigmatism eyepiece design like the SE.

Overall, I'm quite impressed with the optics of this binocular. If production samples live up to the prototype the EDG binoculars should be perfectly capable of jostling with Leica, Swarovski and Zeiss for a seat at the head of the $2000 binocular table.
 
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Boomer

Well-known member
Henry,
Thanks for the great review! I, like many, have been chomping at the bit to read an objective review of the EDG bins. I'm glad to see that they will be competitive with the 'top three.' I will have to start saving up for some EDG bins...probably take me a while :C. At least I know that when I can finally afford a pair, the money will be well spent :-O...I can't wait! Best Wishes.

Ron Davidson
 

SUPPRESSOR

Well-known member
but all the high end roof prism binoculars have more lateral color than just about any garden variety Porro with a simple doublet objective.
Henry,
I had a pair of Nikon 8x32 se Binoculars which showed a large amount of CA ,veiwing birds in flight was always a dissapointment due to large smudges of CA. On the other hand I owned an early pair of 8x42 Trinovids BA's that showed no CA under any viewing conditions,only wish I had not sold them. Also the Nikon LXl's show more CA than the original LX due to the fact that the latter had lead and arsenic in the glass. One of the reasons for the use of ED,fl glass etc in binoculars today is to compensate for the lack of heavy metals in optical glass.
As always thanks for an interesting review.
fiddler.
 

Tvc15_2000

Well-known member
This has come up before. At that time I called Nikon to ask about lead and arsenic (mmm yummy cocktail). Nikon confirmed they switched to lead free Eco-Glass when they introduction of the LX line of binoculars several years ago but did not advertise it at that time.

Perhaps the differences you are observing between LX and the LXL may be due to factors other than lead and arsenic free eco-glass?

Its a level playing field where lead free glass is concerned. Not only for Nikon LX & LXL - Leica and Zeiss are lead free too (I called), and has been for years. I have not called Swarovski yet but I would be shocked if they were still using lead.

Great EDG review. Thank You.
 
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Pileatus

"Experientia Docet”
United States
I had the opportunity to briefly test a prototype of the new Nikon 7x42 EDG binocular today. I didn't have time to be as careful as I would have liked and used abbreviated versions of my usual tests which included resolution and artificial star testing at boosted magnification of 56x and examination of a CA target for longitudinal CA at 56x and lateral CA at 7x. I was able to very briefly compare the EDG to a Zeiss 7x42 FL, a Leica 8x42 Ultravid (non HD) and a Nikon 8x42 LX L, looking mainly for differences in brightness, contrast and color transmission.

After just a few minutes it was clear that the EDG has MUCH higher light transmission than the LX L, and, I believe, slightly better contrast and a little more neutral color (there's just a slight hint of the usual Nikon red). Light transmission in the LX L series really needed improvement and the difference is quite obvious. The EDG appeared to be just slightly dimmer than the Zeiss FL and just a bit brighter than the Ultravid. The EDG is probably about as bright as current technology allows a complex binocular with a Schmidt-Pechan prism to be.

An artificial star test at 56x (Christmas tree ornament in sunlight) revealed a little misalignment in the left barrel (probably a side effect of collimation and pretty harmless). The right barrel was completely free of assembly defects, with just the expected aberrations. It was not the very best looking star test I've seen from a binocular, but, by binocular standards there was nothing seriously wrong either. Resolution was perfectly fine, around 3.5 arcsec in the right barrel, about what I would expect from a typical premium 42mm binocular and much better than is needed for a sharp image at 7x.

Longitudinal CA, viewed at 56x, was clearly better than the LX L. The purple fringe on the the CA target was reduced to about 1/4 the width of the fringe seen in the LX L, very similar to the Zeiss FL. The low CA makes the 56x image look quite clean and contrasty compared to most binoculars, again similar to the Zeiss FL. IMO, lateral color (the type of CA you actually see as a color fringe in binoculars at low power) is pretty bad in the LX L series and it appears to be improved in the EDG to about the level of the Zeiss FL, but all the high end roof prism binoculars have more lateral color than just about any garden variety Porro with a simple doublet objective.

There appears to me to be very little rectilinear distortion in the EDG, a design approach similar to the SE series. That's in contrast to the Zeiss FL which employs considerable pincushion with the goal of the eliminating the "rolling ball" effect when panning. Unfortunately I didn't have time for a careful evaluation of off axis sharpness, but my brief impression was positive. I think the EDG probably uses a low astigmatism eyepiece design like the SE.

Overall, I'm quite impressed with the optics of this binocular. If prodution samples live up to the prototype the EDG binoculars should be perfectly capable of jostling with Leica, Swarovski and Zeiss for a seat at the head of the $2000 binocular table.
Henry,

How does the EDG image compare to the SE image we know and love?

John
 

henry link

Well-known member
Henry,

How does the EDG image compare to the SE image we know and love?

John

Thanks guys. Now we will have to hope that the production bins are just as good as the prototype.

Sorry, I didn't get around to comparing the EDG directly to the SE, John. In retrospect I think I should have spent more time evaluating the off axis performance. That's what I consider to be the best thing about the SE series and the area where I would expect the EDG could be superior to the other "alpha" bins.

Henry
 

jogiba

Well-known member
I agree with the brightness of the 7x42 Zeiss FL's since my pair looks brighter than my Celestron Oceana 7x50 WP-IF/RC's or my 9x63 Pentax DCF roofs.
 

henry link

Well-known member
I was able to spend more time with the 7x42 EDG prototype today. This time I concentrated on comparing its off-axis behavior to several other binoculars (Zeiss 7x42 FL, Leica 8x42 Ultravid, Nikon 8x42 LX L, Swarovski 8.5x42 EL and Nikon 8x32 SE). I also compared the glass reflection patterns and colors between the EDG and the LX L to try to see how things have changed in the new binocular.

Beginning with the reflection patterns, I found that the optical formula for the EDG and LX L eyepieces appears to be almost, but not quite, identical. The reflections at the objective end were also very similar. I don’t think any radical change has been made to the basic optics. In fact, I found the pattern of off axis performance in the new binocular to be nearly identical to the old one as to astigmatism, field curvature and distortion. The big improvements in the EDG are in the areas of light transmission, color accuracy and lateral color. The coatings colors are slightly different. Some reflections that are green in the LXL are an almost colorless dark gray in the EDG.

To test off-axis astigmatism and field curvature I use a ruler with a grid pattern placed vertically through the middle of the field. I focus on the center, then examine the deterioration in the sharpness of the grid pattern as I move my eye to the bottom of the field. Binoculars with a large amount of astigmatism will not allow the vertical and horizontal lines of the grid to be focused simultaneously near the edge. The higher the astigmatism the more focus shift is required to change from sagittal focus on the horizontal lines to tangential focus on the vertical lines. Binoculars with mostly field curvature soften at the edge, but can be refocused for both vertical and horizontal lines simultaneously. I refocus the edge for “best” focus on both sets of lines, then compare that to center focus, using reading glasses of different strengths to measure field curvature.

The off axis performance of the EDG and LX L were superior to any of the other binoculars in this test, even the excellent SE. The Zeiss FL has the most off axis astigmatism and the softest field edge, followed by the Leica and Swarovski. All three Nikons showed lower astigmatism and sharper field edges, but the SE has about 2.5-3 diopters of field curvature while the EDG and LXL have only about 1.5 diopters, so for my unaccommodating eye the EDG and LX L look sharper at the edge than the SE.

Today’s tests reinforce my earlier impression that the EDG binoculars should be very strong competition. This prototype gives up just a little brightness to the AK prism of the Zeiss FL, but is easily superior to the Zeiss, Leica Ultravid and Swarovski EL off axis.
 

Boomer

Well-known member
Aw Henry...you've done it again!:t: Thanks for the great review. I'm still saving up for a pair...but after your review, I'm considering skipping lunches to move my purchase date forward. Best Wishes.

Ron Davidson
 

Surveyor

The more I understand, the more I understand why I
focus, using reading glasses of different strengths to measure field curvature.

Hi Henry;

Reading your post reminded me of a set of lenses I bought a few years ago. I use them for curvature, overdrive and estimating or offsetting known diopter positions, etc.

Mine are 1/2D to 5D, then 1D steps to 10D. Also available are 1/4D to 3D then 1D to 5D. I use 10D camera close up lenses to extend the range from there.

BTW, these sets are + and – diopter. I bought mine used for about $20, shipped.

You may already have something similar or better but thought I would mention it. Have a good day.

http://cgi.ebay.com/Retinoscopy-Rac...ryZ31466QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Ron
 
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elkcub

Silicon Valley, California
United States
Ron,

Thanks for the tip. I may buy a set. :t:

Henry,

Nice work! How would you compare the handling qualities of the EDG to the Swaro? I really enjoy the fast focus of the 8x32 LX L, as well as the accurate diopter control. I find the Swaro less attractive.

Ed
 

henry link

Well-known member
Ron #1

Thanks for the vote of confidence, but, as you can see from reading this forum, people never agree about binoculars. I trust you'll check them out for yourself when they become available.

Ron #2

Interesting, I didn't know about those lens sets. I've accumulated a house full of reading glasses of different strengths, which seem to work well enough for quantifying field curvature as long as I focus at the field edge first, then use the glasses to measure the focus difference between the edge and the center.

Ed,

I can't say much about handling. Most of the time the binoculars were on a tripod. I didn't notice anything unusual or uncomfortable, but I'm not very critical as long as the focuser is on the back end of the hinge where God intended it to be and the focus is not too slow. Diopter adjustment is no longer on the eyepiece. It resembles the Swarovski system, but the focusing knobs on the prototypes have been prone to inadvertently slip into diopter adjusting mode too easily. That happened to me several times. Nikon is supposed to be fixing that problem in production units.

Henry
 

npos

Well-known member
What optical sacrifices (if any) are made to achieve the capability of very close focus? The Zeiss FLs are very good in this respect, by the way.

Norm P
 

henry link

Well-known member
Norm,

The only optical problem I can imagine resulting from very close focus in binoculars that use moving eyepieces or moving objectives would be vignetting from a prism aperture. That could happen at close focus with a moving eyepiece or distant focus with a moving objective. I suppose spherical aberration will increase at very close focus, but I don't think that will be visible at binocular magnifications.

As for binoculars that use moving focusing lenses like the Zeiss, I just don't know. Maybe somebody else has some ideas about that.

Henry
 

henry link

Well-known member
Mike,

I would expect the improvements in light transmission and color accuracy to carry over to all the EDG binoculars. I see quite a lot of lateral color (CA) in the 8x32 LXL image, more than the 8x42 LXL. It will probably be reduced in the 8x32 EDG, but I'm not certain about that. We'll just have to wait and see.

Henry
 

henry link

Well-known member
My understanding is that the EDG binoculars have been delayed to take care of the diopter adjustment problem, so maybe sometime in the fall.
 

ceasar

Well-known member
Hi Henry,
I wonder why Nikon didn't stay with the diopter adjustment ring they have on the LX L's? It is simple and reliable. Once set, it stays set. As the saying goes: "If it ain't broke, don't fix it!"

I take it that the new diopter adjustment is similar to that used by Leica in it's Trinovid/Ultravid line. It works fine on my 7 x 42 Trinovid but it strikes me as being technical overkill. Vortex tried something like it on their new 6.5 x 32 Fury's but had to recall them because it wasn't working properly.

Do you know any reason why it is superior to the common right eye diopter ring?

Bob
 

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