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Nikon 18x70 measures

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#26 hallelujah

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Posted 17 October 2010 - 05:22 PM

Thanks for that , Stan !

Far preferable to just the link :-)
Kenny


Kenny,

My typing skills are atrocious. (?cixelsyd)(dyslexic?)
I spend the majority of my life proofreading and editing, and still find errors after-the-fact. :(

Links help me to maintain what little sanity I have left. :crazy:

Stan

#27 Jawaid I. Abbasi

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Posted 17 October 2010 - 06:59 PM

See the price list !! No wonder it must be good. I can only deamed about it :)

#28 captain11

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Posted 18 October 2010 - 01:38 AM

"No wonder it must be good."

Well not neccesarily. All of that rolling globe effect in the Astroluxe costs you a pretty penny whereas you can get pincushion distortion for far less with the Fujis. The EDG line is still far less than their European counterparts.

The WO 22X70 ED APO has parts manufactured in China, but the lenses are manufactured in Taiwan. Assembly is performed in Taiwan. $697 is a heck of a price for semi APO. At that price it is obligatory China has a hand in their manufacture.

#29 Richard McC

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Posted 18 October 2010 - 01:44 AM

Regarding the Nikon 10x70 that EdZ has tested, I believe Dave is correct and this is not the Astroluxe model which would have red rings around the objectives and a field flattener element before each eyepiece. That fits with EdZ's observations regarding curvature because I'm pretty sure that the 10x70 Astroluxe and the 7x50 Prostar are the same from the prisms back (i.e., the objective barrels of the 10x70 Astroluxe are longer and contain objectives which are larger and have longer focal length than those of the Prostar, otherwise the two binoculars are the same).

#30 mercedes_sl1970

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Posted 18 October 2010 - 03:35 AM

Hi Edz

Terrific reviews and information. I think this thread also highlights rather well the need to make assessments of binoculars side-by-side, rather than on vague recollections (as I have done in another thread). And, to have this done in such a systematic way.

So, I'm just curious, in that hypohetical question of "I'm off to a desert island and must choose between the Fujinon or the Nikon, which would it be?" Probably an unfair question, but, I'm sure there are a few people wondering!

Thanks again for the review and your excellent work here on CloudyNights.

Andrew

ps I would also be taking "Kind of Blue" by Miles Davis.

#31 EdZ

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Posted 18 October 2010 - 05:36 AM

Regarding the Nikon 10x70 that EdZ has tested, I believe Dave is correct and this is not the Astroluxe model which would have red rings around the objectives and a field flattener element before each eyepiece. That fits with EdZ's observations regarding curvature because I'm pretty sure that the 10x70 Astroluxe and the 7x50 Prostar are the same from the prisms back (i.e., the objective barrels of the 10x70 Astroluxe are longer and contain objectives which are larger and have longer focal length than those of the Prostar, otherwise the two binoculars are the same).


I'm still not certain of this.

What is most perplexing is this. Comments from history and several comments in this thread imply that the red ring constitutes the presence of a field flattener. We would normally expect the binocular with the field flattener to have lower degree of curvature present.

In the binoculars I'm testing the 10x70 does not have a red ring. The 18x70 does have a red ring. Yet by two different methods of measures, one by measuring double stars across the positions of the fov and the other more precise by measuring line pairs at positions in the fov and then refocusing to measure the curvature that can be focused out, the red ring 18x70 has more curvature present than the 10x70. This does not seem to agree with what should be expected.

Both the 18x70 (the most) and 10x70 have far more curvature than the 7x50 Prostar (the least). Comparing the 3 Nikons I have on hand, it is apparent the 18x70 eyepieces are different than the 10x70 and 7x50. At least from outward appearances, the later two appear to have identical eyepieces.

Could it be that the 72° Afov eyepieces used in the 18x70 would put up such a poor off-axis image if they were used without a field flattener, that it is necessary to employ the field flattener just to get them to come close to the performance of narrower eyepieces?

edz

#32 Fomalhaut

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Posted 18 October 2010 - 07:01 AM

EdZ,

As far as I know, field curvature depends on focal length, plus its perceptibility on magnification (especially due to variable focal range of sharpness [hope I translated this ~properly]). Hence 18x70 (~f4.5) should be more susceptible to it than 16x70 (~same f-ratio), plus 22x70 (~f/6) should be less susceptible than 18x70.

All three either without or then all three with field flattener, of course...

Chris

#33 EdZ

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Posted 18 October 2010 - 07:56 AM

but my comments were regarding the Nikon 10x70 vs the Nikon 18x70. Both have exactly the same focal length. Also, I would put the focal length of the Fujinon 16x70 as near eqaul to both those Nikons. My rough estimate shows almost no difference.

Both tests I do for curvature are done such that I eliminate perception due to magnification. Therefore, I'm not reporting the perception of curvature, I'm reporting the actual measured curvature.

Where is the value f/4.5 for the 18x70 coming from? My quick estimte for the focal length of the Nikon 18x70 results in an f ratio of f/4.2, almost exactly the same as the Fujinon 16x70.

edz



#34 Fomalhaut

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Posted 18 October 2010 - 08:56 AM

but my comments were regarding the Nikon 10x70 vs the Nikon 18x70. Both have exactly the same focal length. Also, I would put the focal length of the Fujinon 16x70 as near eqaul to both those Nikons. My rough estimate shows almost no difference.

Both tests I do for curvature are done such that I eliminate perception due to magnification. Therefore, I'm not reporting the perception of curvature, I'm reporting the actual measured curvature.

Where is the value f/4.5 for the 18x70 coming from? My quick estimte for the focal length of the Nikon 18x70 results in an f ratio of f/4.2, almost exactly the same as the Fujinon 16x70.

edz


There were tests on European forums which describe the red-ringed 10x70 Astroluxe's FOV as having virtually no aberrations at all, and even of being the best of all 10x70s. Hence, I strongly suspect the non-red-ringed 10x70 which you've tested as having NO field-flattener, and the red-ringed one as having one (two, of course :)).

The 10x70-AFOVs are quite smaller than the ones of 16x70 or 18x70. So their FOVs are expected to show quite less field-curvature, but only if tested under same inherent conditions (i.e. field-flattener or not!).

F4.5 was just a rough guess. If they are f4.2, then the 22x70's relative superiority in having less field-curvature is explained even more distinctly, in this case.

Chris

#35 EdZ

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Posted 18 October 2010 - 09:41 AM

There were tests on European forums which describe the red-ringed 10x70 Astroluxe's FOV as having virtually no aberrations at all, and even of being the best of all 10x70s. Hence, I strongly suspect the non-red-ringed 10x70 which you've tested as having NO field-flattener, and the red-ringed one as having one



Based on my tests, I suspect the red-ring 18x70 DOES NOT have a field flattener. Frankly, I'm not too concerned about the Nikon 10x70 with no red ring. It shows lower curvature and lower overall image aberrations than the 18x70.

In another recent post regarding selection of a 10x70, there was a pointer to decade old discussions on Europa.com regarding the 18x70s and 10x70s vs Fujinons. Even on that reliable website, there is misinformation regarding these binoculars. For instance a notable reviewer states the 10x70 Astrolux as having ED glass, when in fact it has been confirmed it does not have ED glass. My false color tests support that difference as fact vs fiction. Also, I've read numerous posts in various places that the Nikons have superior image right to the edge of field. Compare that to my observed and noted measures where in fact we find the 18x70 Nikon, at the edge of the field, instead of a stellar point, shows stars as lines 2-3 arciminutes long that look like star trails in a time exposure photograph!

I've read so much misinformation about this particular line of binoculars that I question the statement that the red ring indicates a field flattener?

Perhaps that is simply more misinformation, carried over from the fact the Prostar has a field flattener (that really works effectively) and has a red ring.

It may very well be true that all Nikon binoculars that have field flattenrs have red rings. That does not necessarily make it true that all Nikon binoculars with red rings have field flatteners.

edz

#36 Fomalhaut

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Posted 18 October 2010 - 10:00 AM

There were tests on European forums which describe the red-ringed 10x70 Astroluxe's FOV as having virtually no aberrations at all, and even of being the best of all 10x70s. Hence, I strongly suspect the non-red-ringed 10x70 which you've tested as having NO field-flattener, and the red-ringed one as having one



Based on my tests, I suspect the red-ring 18x70 DOES NOT have a field flattener. Frankly, I'm not too concerned about the Nikon 10x70 with no red ring. It shows lower curvature and lower overall image aberrations than the 18x70.

In another recent post regarding selection of a 10x70, there was a pointer to decade old discussions on Europa.com regarding the 18x70s and 10x70s vs Fujinons. Even on that reliable website, there is misinformation regarding these binoculars. For instance a notable reviewer states the 10x70 Astrolux as having ED glass, when in fact it has been confirmed it does not. My false color tests support that difference in fact vs fiction. I've read numerous posts in various places that the Nikons have superior image right to the edge of field. Compare that to my observed and noted measures where in fact we find the 18x70 Nikon, at the edge of the field, instead of a stellar point, shows stars as lines 2-3 arciminutes long that look like star trails in a time exposure photograph!

I've read so much misinformation about this particular line of binoculars that I question the statement that the red ring indicates a field flattener?

Perhaps that is simply more misinformation, carried over from the fact the Prostar has a field flattener (that really works effectively) and has a red ring.

It may very well be true that all Nikon binoculars that have field flattenrs have red rings. That does not necessarily make it true that all Nikon binoculars with red rings have field flatteners.

edz


EdZ,

There will probably be no further and reliable answer to the above questions and assumptions (in the 10x70's case also of yours) until a red-ringed Nikon 10x70 will finally have been investigated thoroughly...

Chris

#37 RichD

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Posted 18 October 2010 - 10:26 AM

Even though it is off topic a bit, The mediocre edge correction of the 18x70 just makes me even more in awe of the flat field of the fujinon 10x50 FMT - given it's wide AFOV (very similar to the nikon) and moderate cost.

#38 Rich V.

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Posted 18 October 2010 - 11:00 AM

Reviewing a couple Nikon USA catalogs I have, in 1996 only the #7789 Prostar (7x50 IF SP WP) and the #7893 10x70 Astroluxe (10x70 IF SP WP) are listed. Both are shown with the red ring.

From that catalog:

"The 7x50 Prostar, dubbed the binocular for connoisseurs in Astronomy Magazine, features the finest low dispersion optical glass, specially multicoated and corrected for coma and all other aberrations for an incredible view of the stars. The 10x70 SP Astroluxe boasts the same features as the Prostar but with added power for wildlife, in addition to astronomy observation with increased detail."

The 2003 calalog includes the addition of the #7447 18x70 Astroluxe XL. The descriptions of the Prostar and Astroluxe binoculars are similar to the 1996 catalog, referring to full multi-coatings and "coma corrected optical glass". The photos of all three models show red rings.

There is no mention of field flatteners anywhere, just the "coma correction".

Nikon's history page shows the 10x70 IF SP WP being introduced in 1990 and the 18x70 being introduced in 1997. I wonder if the red ring was present in 1990 or if it was added at a later date; I see no listing for any other 10x70 model.

Rich V

#39 Les

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Posted 18 October 2010 - 01:27 PM

My red ringed Nikon 18x70 sold as "Astroluxe" by USA dealer had no mention of field flattener element in the documentation that came with them. To my knowledge only 10x70 Astroluxe has the field flattener. My own research of dealer ads, manufacturer websites, and documentation leads me to believe that Nikon Japan recommended the 10x70 Astroluxe for astronomic use and the 18x70 for terrestrial. No recommendation for astronomic use. USA dealers selling product with same model #/UPC code seem to have extended the recommendation of the 18x70 to astronomy. And they are fine glasses for such use but pricey.

#40 dOP

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Posted 18 October 2010 - 01:33 PM


Thanks pcad.

The Prostar (7x50) has Red Rings and has a Field Flattener. The (10x70), SP version, is virtually identical, probably has Field Flattener.

The 18x70, although with Red Rings looks like a different animal. It has not the "SP" designation. I bet it has different optics.

#41 EdZ

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Posted 18 October 2010 - 03:28 PM

The Prostar (7x50) has Red Rings and has a Field Flattener. The (10x70), SP version, is virtually identical, probably has Field Flattener.

The 18x70, although with Red Rings looks like a different animal. It has not the "SP" designation. I bet it has different optics.


From everything that I've read so far, SP simply seems to refer to their high grade coatings (Fujinon refers to theirs as EBC). It is not a glass type or a reference to any additional elements or correction in the optics. Essentially, it seems to be a reference to full multi-coating (FMC).

Nikon Japan recommended the 10x70 Astroluxe for astronomic use and the 18x70 for terrestrial. No recommendation for astronomic use.



Previous comments I've read (dating from 4 to 10 years ago) indicated the only reasoning that could be found behind what was recommend for astronomy was the 7mm exit pupil, a long outdated criteria.

The descriptions of the Prostar and Astroluxe binoculars are similar to the 1996 catalog, referring to full multi-coatings and "coma corrected optical glass". The photos of all three models show red rings.

There is no mention of field flatteners anywhere, just the "coma correction".



I'm fairly certain the only correction for coma is in the figure of the objective lens. So that's simply referring to a comment that would be similar to saying "these binoculars have a very well figure lens". Coma simply is not a problem in many well-executed binoculars that I've used. In lesser quality optics, coma and astigmatism combine to give that off-axis seagull flying around in the outer field of view. Without coma those flying seagulls show up as long star trails curved parallel to the arc of the field stop.

edz

#42 Les

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Posted 18 October 2010 - 06:12 PM

Previous comments I've read (dating from 4 to 10 years ago) indicated the only reasoning that could be found behind what was recommend for astronomy was the 7mm exit pupil, a long outdated criteria.


In as much as Nikon seems to recommend their SP glass binos for astronomy, I would suppose that is the reason for the recommendation on the 10x70 Astroluxe and not the large exit pupil.

#43 John F

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Posted 18 October 2010 - 10:13 PM

Rich,

I think that you are right. I remember when Nikon introduced the 10x70 IF SP Astroluxe binocular back in the early 1990s and the were specifically saying it was basically a larger aperture and higher power version of the Prostar and included the same performance enhancing features that made the Prostar so well suited for astronomical use. And like the Prostar the 10x70 includes the red rings around the front barrel. What exactly that signifies (if anything) I'm not sure.

Having owned both the 7x50 Prostars and 10x70 Astroluxes for over 5 years now I've had numerous opportunities to compare them. And it appears to me that the 10x70s are just as sharp out to the edge of their field as the 7x50 Prostars are.

Also, I had a chance to compare (for a few hours) the 10x70 Astroluxes to the 10x70 Fujinons and the while the Fujinons are still an excellent binocular as well as value, the 10x70 Nikon IF SP Astroluxes retained their edge of field sharpness better. At any rate, from Ed's description of the performance of the Nikon 10x70s he tested I seriously doubt if he was testing a pair of the 10x70 Astroluxes.

However, my experience with the 18x70 Nikons does match with what Ed reported. Overall, it is a great binocular but its edge sharpness is not a good as the 16x70 Fujinons and it also flares somewhat on brighter stars. However, because of its higher power, wider apparent field, and excellent on-axis performance I still prefer the views it delivers (most of the time) to what I seen in 16x70s. However, by any absolute standard the 16x70s are a great binocular and relative to the Nikon 18x70s a much better value for what they cost. That said, if I didn't make the switch to the Zeiss 15x60 BGATs back in 2003 I'd probably still have my old pair of Nikon 18x70s.

Fortunately, I sold my pair of 18x70s to an observing buddy and usually brings them on summertime dark-sky observing trips so I still get a chance to use them every summer and the views they provide are still engaging enough that I enjoy using them and on several occasions have debated whether or not I should get another pair.

John Finnan

#44 Rich V.

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Posted 19 October 2010 - 01:37 AM

At any rate, from Ed's description of the performance of the Nikon 10x70s he tested I seriously doubt if he was testing a pair of the 10x70 Astroluxes.


Hi, John,

It's odd as the only other 10x70s Nikon lists are the 1974 10x70 IF WP and the 1979 10x70II IF WP. Could it be that Ed has a 1970's version? I don't know how long Nikon produced the 10x70II IF WP; maybe it went through the '80s. I would expect only the MgFl coatings of the time on the earlier models. There's nothing else listed until the 1990 10x70 IF SP WP Astroluxe. :confused:

Nikon History

Rich V

#45 mercedes_sl1970

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Posted 19 October 2010 - 03:34 AM

However, my experience with the 18x70 Nikons does match with what Ed reported. Overall, it is a great binocular but its edge sharpness is not a good as the 16x70 Fujinons and it also flares somewhat on brighter stars. However, because of its higher power, wider apparent field, and excellent on-axis performance I still prefer the views it delivers (most of the time) to what I seen in 16x70s. However, by any absolute standard the 16x70s are a great binocular and relative to the Nikon 18x70s a much better value for what they cost.

John Finnan


John - hope you don't mind me selectively quoting you here, but your assessment echoes mine, except that I don't find the lack of edge sharpness or flaring quite so obvious (that's probably more a comment on my lack of discernment/experience). I do find overall, that the 18x70s just seem to work better for me - it's the "sum of the parts..." argument. But, on my modest budget, if I was paying the retail price, I'd have to go with the Fujinons.

Andrew

#46 Richard McC

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Posted 19 October 2010 - 04:52 AM

Rich, Nikon currently sells two different 10x70 binoculars: the 10x70IF SP WP (also called the Astroluxe) and the 10x70IF HP WP. The Astroluxe version has red rings around the objectives and is grouped with the Prostar in Nikon's literature and on their web site. Other differences are that the Astroluxe has more eye relief (16.3mm v 15mm), is a little heavier (2.1kg v 1.985kg) and has a shorter close focusing distance (25m v 50m). On their web site Nikon also talk about the Astroluxe's "Superior optical design for aberration-free observation, built especially for astronomical use". I'm pretty sure that the Astroluxe has a field flattening element behind the prisms just like the Prostar, perhaps the HP model lacks this element and/or has a simpler eyepiece design? I don't know what if any other differences there may be between the two models (coatings have been suggested by some).

I am guessing that EdZ has the HP and not the Astroluxe model in his possession (if somebody wants to loan him a Nikon 10x70 with red rings we can find out for sure). This two tier arrangement of 10x70 binoculars is very much like Fujinon with their FMT and MT series. However, unlike Fujinon there is only a single higher magnification binocular from Nikon, the "18x70IF WP WF". This gets red rings around the objectives and much wider AFOV eyepieces than the 10x70 models and I don't know what if any other differences.

#47 EdZ

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Posted 19 October 2010 - 06:29 AM

The Astroluxe version has red rings around the objectives and is grouped with the Prostar in Nikon's literature and on their web site. Other differences are that the Astroluxe has more eye relief (16.3mm v 15mm), is a little heavier (2.1kg v 1.985kg) and has a shorter close focusing distance (25m v 50m).



This Nikon 10x70
is all black
has no red rings
is marked as a 5.1° fov
close focus is measured as 23mm
weighs 1930g (inaccurate kitchen scale)
eye relief is about 19mm
has slightly less field curvature than the 18x70
has less rersidual (all other) aberration than the 18x70 after curvature is subtracted out.

edz

the 18x70
is black with red rings
marked 4° fov, measures 4.0°
weighs 1980g.
close focus is measured at about 60m.
eye relief is 17mm.

Let me point out that the way they are grouped on their website today may not necessarily reflect the way they were grouped 5 or 10 years ago. So, unless these binoculars were new today, I'm not sure the current website grouping tells us anything definitive. I might also add, there is as much guessing and potential misinformation going on in this thread as what I've seen in 10 years of history discussions regarding these binoculars. Weed out all the guesswork and surmising and we still do not know what these binoculars are.

edz

#48 Richard McC

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Posted 19 October 2010 - 07:02 AM

Both of Nikon's current 10x70 binoculars have a FOV of just over 5° (they have had 6.5° and 7° versions in the past). The curvature you measure and the lack of red rings makes me think that you have the HP (non Astroluxe) version. The other discrepancies I can easily put down to Nikon's specifications being a little out (alas not unusual for Nikon).

#49 dOP

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Posted 19 October 2010 - 09:25 AM


Just for reference:

http://www.cloudynig...php?item_id=216

The author observations basically supports Edz's measurements. I also suspect the 10x70SP is as good as the Prostar - these are the only labeled "SP" (someone said it means "special performance") and are the only recommended instruments for Astronomy by Nikon.

The 18x70's FOV is very wide, if you limit it to 50 or so degrees, it probably performs as good as the Prostar. Another hypothesis is that it has the same optics as the 10x70, except for the eyepieces. Since a binocular is a complex optical system, its components must be designed to work as a whole. If you put shorter focal length eyepieces in a 10x70SP to give a 18 power, the field flattener would probably not work the same way it works on the 10x eyepieces resulting in sub-optimal performance, not deserving the "SP" designation. That could be done to shave manufacturing costs, the bodies, prism assembly, objectives, field flatteners could be the same for the 10x70 and 18x70 versions, differing only in the eyepieces. That would also explain - if the red rings mean "field flattener present" - why all the versions feature red rings and the 18x70 perform worst. Just an hypothesis...

#50 EdZ

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Posted 19 October 2010 - 12:32 PM

Regarding the use of same system across several sizes of binocular, another member suggests the same hypothesis. That is a possibility.

regarding the article referenced note these quotes from the article, Marcus makes some good points, but,

The Nikon Multicoating is the best multicoating I have found in any comparable bino. You look into these lenses and you dont see them, it's like looking through air.



I've pointed this out before. Looking thru the lens tells you very little information about the coatings. You can do this with almost any multi-coated lens.

It is fully flat field, zero distortion, put an housecorner or electric cabel in the center and move towards the edge, the lines at the edge are as straight as in center.



What he describes, lines on edges straight as center, has NOTHING to do with flat field. He is describing a lack of pincushion distortion. So he has not provided ANYTHING that tells you whether or not it is flat field.

...with a little noticable chromatical aberation ( faint green-violet) on sharp corners.
Anyway I checked the power on night sky. Moon is nearly colorfree and racersharp , like looking with lower apo through an high quality ED- Apo.



Hmmm, my tests show false color equal to the Fujinon 16x70 and the much less expensive Oberwerk Ultra 15x70, especially on the Moon. It does not look anything like any Apo, or for that matter even like an ED semi-Apo. See my comparison in this thread to the WO22x70, which is labeled as Apo, but I've already noted in reviews (comparing to Tak 22x60) is not Apo.

The edge correction is not perfect , but still excellent, very similar to other such large high quality binoculars.



If the Fujinon would be considered a very similar large high quality binocular, the Nikon 18x70 does not match it for edge correction. Markus agrees with that.

I'd agree with the claims of razor sharp (on-axis) and high quality and edge correction not perfect. I'd disagree with his comments about flat field and chromatic aberration. The coatings are among the best, but Markus' example doesn't really support that.

edz


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