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Nikon 18x70 measures

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#1 EdZ

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Posted 16 October 2010 - 01:48 PM

all results here are measured

aperture 69mm
magnification 17.25x to 17.5x
exit pupil 3.9 to 4.0mm

I used two methods to check aperture; my laser method and the flashlight shined thru the eyepiece. All measures agreed.

I calculated magnification using the three masks method. I used full aperture, a 60mm mask and a 50mm mask, measuring exit pupils at each aperture. I got results that gave magnifications ranging from 17.1x to 17.5x. Most of results were in the range I stated above for magnification.

on axis line pairs resolution 4.2 arcseconds.
At 17.5x = 74 arcseconds apparent. Excellent. Equal to Fujinon 16x70 (75 arcsec apparent). Better than Pentax 20x60 and any 20x80 I've used. Nearly equal to Tak22x60 and WO22x70. Slightly better than Obie Ultra 15x70 and GO Sig 22x85.

off axis sharpness by 60% out already falls off more than the Fujinon 16x70. By 80% out the Fujinon starts to get close to the same total aberrations as the Nikon. So, at both 60% and 80% out the Fujinon is better than the Nikon, but more-so at 60%.

The Nikon outer field aberration appears to be near entirely due to curvature. I could focus out nearly all of the distorted image at 60-70% out. This is not something I would ever do in practical use. I measured 2.0 to 2.5 diopters of curvature at 60% and ~3.0 dipoters of curvature at 80% out. In both cases this was 1.0 to 1.5 diopters more than the Fujinon.

A note for comparison, the Nikon 10x70 has only 1.0 to 1.5 diopters of curvature at ~80% out however with a much narrower Afov. It should also be noted that there are other aberrations remaining in the view of the 10x70 after curvature is focused out. The Nikon Prostar 7x50 has no curvature at all. In fact it has so little off-axis aberration it can't even be compared to the 10x70 or the 18x70. The better comparison to the 18x70 is probably to the Fujinon.

At this point I would note, there have been lengthy discussions in the past about this binocular containing ED glass AND having a field flattener. The myth of having ED glass has been dispelled. It does not, verified by comments directly from Nikon. However, I'll question here the use of a field flattener. A field flattener is used to eliminate curvature. I have measured noticable curvature in the Nikon 18x70, more curvature than the Fujinon 16x70. So, maybe this 18x70 does have a field flattener, but if so, it certainly doesn't flatten the field as much as the Fujinon.

Close focus Nikon about 240 feet (75m), Fujinon about 100 feet (30m).

The Nikon 18x70 weighs 70 ounces (4#6oz, 1980g.) Thats 6oz. (70g.) less than the old Fujinons.

The Nikon appears to have little or even zero pincushion. Although I couldn't see it, I suspect it has a small amount of barrel distortion. I base that on the fact that I measured the real AFOV (using the half angle) at 67°. However, the TFOV is measured at 4.0° and therefore the effective field stop AFOV is 70°. When effective Afov is larger than real Afov, that signifies barrel distortion.

I wrote previously, the Nikon 18x70 has considerable globe or rolling ball effect. Pincushion is purposely designed into binoculars to eliminate this effect, and as noted in the previous paragraph, the Nikon has no pincushion. The Fujinon 16x70 appears to have no globe effect. It is noticable in the Nikon when panning in daylight. It is far more noticable (if not dizzying) when panning at night. It is not noticable when not panning.

The stock round plastic Nikon eyecups take up too much eye relief. IMO, I could not use them with my eye glasses. The usable eye relief with these stock hard plastic eyecups is 7mm. I replaced the Nikon hard cups with the rubber eyecups. The usable er with the Nikon rubber eyecups is 12mm.

Even with the rubber eyecup folded down and 12mm of usable eye relief, with glasses on, I cannot see the entire field of view. I estimate loss of fov at between 5%-10% just about the same loss of fov I experience with the Fujinon.

Outside diameter of eyecups at the back end Nikon 44mm, Fujinon 48mm
Space between eyepieces at my IPD63mm Nikon 19.5mm, Fujinon 16mm.

Both the Nikon and Fujinon have 22mm eye lens. However, the Nikon with the rubber eyecup has only 19mm of the lens exposed. No big deal.

Illumination in the Fujinon 16x70
the central 50% of the aperture provides full illumination. 90% of the aperture provides 50% illum.

Illumination in the Nikon 18x70
the central 40% of the aperture provides full illumination. 90% of the aperture provides 50% illum.

No 20x60 or 20x80 binoculars that I've tested have greater than the central 30% of the aperture providing full illumination. The Nikon 18x70 illumination (40%) measures less than the Fujinon 16x70 (50%) and WO 22x70 (50%), about the same as the Signature/Ultras (35-45%), the same as the Fujinon 10x50 (40%), but better than all of the Nikon SEs (20 to 30%).

that's all for now. I need lot's of time outside at night with these.

edz


#2 KennyJ

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Posted 16 October 2010 - 03:26 PM

Thanks for that information , Ed .

Kenny

#3 EdZ

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Posted 16 October 2010 - 04:59 PM

as always, you're welcome
edz

#4 Rich V.

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Posted 16 October 2010 - 06:07 PM

Great technical review, Ed. Now, after all these years, these Nikons aren't such a mystery around these parts.

I'm looking forward to your viewing impressions; are the coatings, light transmission and contrast on par or superior compared to the Fujinons?

Rich V

#5 EdZ

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Posted 16 October 2010 - 09:14 PM

chromatic aberration

waxing moon 1 day past half full

Nikon 10x70
moon centered in view, see a thin yellow band along the edge, no color on the terminator. I could sometimes see no color on-axis.
moon 70% off axis right, see yellow band, double the intensity from on-axis. Still pretty thin.
70% left, less intense, purple,
images 70% off-axis were pretty good. But 10x is not enough power to see much detail or any of the tiny craters.
images good to about 60% off axis.

Nikon 18x70
moon centered, band along edge is twice or more as prominent in the 18x70 compared to the 10x70.
at 70% out to the R, color is a thick yellow band on the outside edge much thicker than the 10x70.
70% L, the color is a bright blue, broad color band.
sometimes see no color on-axis. image very good. many smaller objects visible.
image good to about 60% off axis.

Fujinon 16x70
moon center and at L and R, the false color is identical to the Nikon 18x70.
The scale is noticably smaller. There is less detail in the tiny craters.
images good to 70% off axis

WO22x70
no color on-axis. 95% out to R, a slight yellow/green could be seen just on the outer 1/3 of the edge. Very thin color band. With moon at extreme L, slight purple color along edge, again only along maye 1/3 of edge. I thought this binocular was fairly remarkable for its near total lack of color both on and off axis. The detail and size made tiny dots easy. Saw many more craters than at 18x or 16x.
images good to about 80% off-axis.

Oberwerk Ultra 15x70
on and off axis color was just about the same as the 16x70, which in turn was about the same as the 18x70.
scale getting too small to see great detail in the many tiny craters. Many not seen at all.
images good to about 70% off-axis.

The Nikon 10x70 with thin color bands was the 2nd best performer with regard to false color, a long step behind the WO22x70. The 18x70 and 16x70 were about equal and considerably worse than the 10x70. In the 10x, 16x and 18x, occasionally the on-axis image would be without color, but most of the time there was yellow in the image. Off-axis there was thick color in the 15x, 16x and 18x.

I did not notice any particular color cast from any one to the other. Nor did I see any difference in brightness in the mid 15-16-18 powers.

For much of this session I didn't even see the field edge. In this instance fov had no influence. Although it has the narrowest field, by far the best performance here was the 22x70.

edz

#6 mercedes_sl1970

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Posted 17 October 2010 - 01:53 AM

Edz - great reviews. It's terrific to have more comparisons made between these binos. Great work as always. And, on the eyecups - Nikon have done these binos a complete injustice.

Andrew

PS I don't find the rolling ball effect quite so pronounced but I'm probably less sensitive to it - heading so many high balls in soccer (football) probably hasn't helped...

#7 Fomalhaut

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Posted 17 October 2010 - 03:38 AM

Edz - great reviews. It's terrific to have more comparisons made between these binos. Great work as always. And, on the eyecups - Nikon have done these binos a complete injustice.

Andrew

PS I don't find the rolling ball effect quite so pronounced but I'm probably less sensitive to it - heading so many high balls in soccer (football) probably hasn't helped...


My Nikon's circular rubber eyecups have an inside diameter of 25 mm, thus not restricting the 22 mm field lens at all.

With its greater apparent field diameter and its darker sky background due to higher magnification, the 18x70 delivers more spectacular views of deep-sky objects to my eyes and brain than the Fujinon 16x70 and, due to smaller outside-diameter of the eyepieces => less obstruction by nose => greater seeing comfort, especially when looking at objects at high angles.

Plus since I strictly use the 18x70 on a tripod, the rolling-ball effect does not bother me at all.

I admit the Fujinon may be the better bargain, but I was ready to pay twice the price for the Nikon's (even if small) advantages.

OTOH, I personally would not be ready to accept the W.O.22x70's 2,8x bigger torque, compared to the 18x70.

Of course, anybody's mileage may vary...

Chris

#8 mark8888

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Posted 17 October 2010 - 03:56 AM

Hi,

>OTOH, I personally would not be ready to accept the W.O.22x70's 2,8x bigger momentum, compared to the 18x70.

I'm curious, what does the word "momentum" mean in this context? What is the momentum of a pair of binoculars?

Thank you very much EdZ for the interesting reviews you have posted here.

#9 Fomalhaut

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Posted 17 October 2010 - 05:25 AM

Hi,

>OTOH, I personally would not be ready to accept the W.O.22x70's 2,8x bigger momentum, compared to the 18x70.

I'm curious, what does the word "momentum" mean in this context? What is the momentum of a pair of binoculars?

Thank you very much EdZ for the interesting reviews you have posted here.


Sorry, what I wanted to say is "torque" (since English is just a foreign language to me, such mistakes occasionally happen):)...
Nikon 18x70 => 293mm x 2,05 kg ~600
W.O. 22x70 => 420mm x 4 kg ^1680
1680 : 600 ~ 2.8

Chris

#10 dOP

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Posted 17 October 2010 - 07:00 AM

Hi!

Ed, what version is the Nikon 10x70 you mention?

The SP like the Prostar (10x70IF SP WP) or the HP, same as Tropicals (10x70IF HP WP)?

Thanks.

#11 EdZ

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Posted 17 October 2010 - 07:12 AM

double stars on-axis resolution and off-axis sharpness

percent is star positioned out in field of view, distance percentage of fov from center.

Alya, theta Serpens 4.5-5.0/22", fairly even mag 5 pair
off-axis limit, or limit of seeing two components as a pair, beyond that blurred into one
Fujinon 10x50--6.7°--- out to 60%
Nikon 10x70--5.0°--- out to 50-60%
Obie Ultra 15x70--4.35°--- 70%+
Fujinon 16x70--4.05°--- 80-90%
Nikon 18x70--4.05°--- out to 50-60%
WO 22x70--3.0°--- 70-80%

Stf 2690, 7.0-7.2/16.7", very even faint pair in tail of Delphinus, fainter magnitude makes this difficult at lower powers
Fujinon 10x50--- out to 20%
Nikon 10x70--- out to 20%
Obie Ultra 15x70--- out to 60%
Fujinon 16x70--- out to 60-70%
Nikon 18x70--- out to 50-60%
WO 22x70--- out to 70%

Gamma Del, 4.5-5.5/9.6", slightly more uneven magnitude, quite noticable big star and small star.
Fujinon 10x50--- not resolved, not detected
Nikon 10x70--- not resolved not detected
Obie Ultra 15x70--- pointed, not resolved
Fujinon 16x70--- barely resolved on axis, slight flair
Nikon 18x70--- out to 20-30%, slight flare
WO 22x70--- 40% good, slightest flair

Mesartim, Gamma Aries, 4.8-4.8/7.8", perfectly even mag 5 pair, but too close for low power.
Fujinon 10x50--- not detected
Nikon 10x70--- not detected
Obie Ultra 15x70--- not resolved but noticed elongation.
Fujinon 16x70--- not resolved but noticed duplicity
Nikon 18x70--- very small split
WO 22x70--- clean nice split (previously the 22x70 split 6.3")

best on-axis resolution on a difficult pair, Y Del, fell right in line with increasing power. So did Mesartim.

Based on the above measured off-axis readings, this in the results in order of sharpness. Order of best field sharpness without regard for total field of view. This is simply a measure of how much of the field of view is sharp compared to the entire fov. Since a higher powered binocular by nature of more powerful magnification, should be able to see closer stars, this is compared in arcseconds apparent (separation x power). Some of this is from previous measures. Closest readings furthest out is best

Fujinon 16x70--- 220 arcsec to 60%, 350 arcsec to 80%
Fujinon 10x50--- 220 arcsec to 60%, 370 arcsec to 80%
Obie Ultra 15x70--- 250 arcsec to 60%, 320 arcsec to 70%
Nikon 10x70--- 220 arcsec to 55%
WO 22x70--- 350 arcsec to 60%, 380 arcsec to 70%
Nikon 18x70--- 300 arcsec to 55%, 380 arcsec to 60%


edz

#12 EdZ

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Posted 17 October 2010 - 09:13 AM

observations of Jupiter
during these observations a 3rd moon appeared moving away from the planet disk towards the west.

Fujinon 10x50-- no belt seen,
Nikon 10x70--no belt seen,
Obie Ultra 15x70-- bright flair, false color blue halo, barely see NEB, 3rd moon not seen after 10 min.
Fujinon 16x70-- no flair, false color blue halo, NEB easy, 5-10 min after first appeared saw 3rd moon,
Nikon 18x70-- no flair, false color blue halo, NEB easy, color shading suspected, 5 min after first appeared saw 3rd moon,
WO 22x70-- no flair, no false color, NEB easy, SPB noticable, 3rd moon first appeared only a few arcseconds away from disk 8:59PM EDT

Again the 22x70 was by far the best of the group. There was only slight noticable difference between the 18x70 and the 16x70. The 15x70 Ultra did not put up as tight an image.


observations for Limiting magnitude Stars.
reference chart M45 in my gallery, see accompaning table of star magnitudes.
NELM was about mag 5.1 to 5.2, not as dark as my skies can get.

the 15x70 Ultra and the Fujinon 16x70 previously reached best LM of mag 11.05 stars under mag 5.5 skies. The WO22x70 reached mag 11.5.

Both the 16x70 and 18x70 saw several stars between mag 10.25 and mag 10.5. Both also saw A29, a mag 10.7 star. Neither could see any mag 10.9 or mag 11.0 stars after considerable effort. The 18x70 could see A21b, the close star paired with A21, by nature of higher magnification. The 16x70s could not see that one. The WO22x70 saw A25 and A27, both mag 11.0 stars. Also, with the 22x70 I suspected seeing A18c, a mag 11.24 star. A21b was seen easily in the 22x70. A2b although not particularly faint at mag 10.3, is right next to a bright mag 7 star. It was seen in the 22x70.


checking extent of field of view.
Only compared the 18x70 to the 16x70.
Both almost exactly span the distance across the bottom of the V of Taurus, gamma Tau to alpha Tau. Both have identical fov, allowing both of those stars to be seen on the very edge of the field at the same time, but just barely. Those stars span almost exactly 4.0°.


deep sky

For deep sky, the 10x70 Nikon and the 10x50 Fujinon were used hand held.

M31, M32, M110
The 22x70, the 18x70 and the 16x70 could just detect M110 above M31. None of the other binoculars could detect M110, but all of them easily could see little M32. M31 was not particularly broader in extent in any of them. There was no noticable darkening or brighter image from the 22x70 to the 18x70 or 16x70. The 10x70 Nikon did show a brighter sky background. The 10x50 Fujinon did seem to show the dimmest overall image.

Comet Hartley appeared about the same in all three big binoculars. The 22x70 gave the best overall image. The 18x70 and 16x70 were nearly identical, even difficult to see any difference in power. All three saw a brighter core and an uneven diffuse extension. The comet was seen in both 10x binoculars handheld, but not nearly as large or bright.

M38, NGC1907 and PN1931
the open clusters M38 and 1907 were fairly easy, obviously larger and with more stars in the 22x70. Both were easily seen and somewhat resolved in both the 18x70 and 16x70. The planetary nebula NGC1931 was first detected in the 22x70 as what looked like a bloated star. It was also detected in both the others, but was difficult in the 16x70 and I suspect only seen in the 16x70 because I knew which one it was. Not attempted with any smaller binocs.

edz

#13 EdZ

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Posted 17 October 2010 - 09:49 AM

The William Optic 22x70 was mounted to a Bogen 501 head on a Manfrotto 028 tripod. WO vertical centerpost mounted directly to 501 QR plate.

The Fujinon 16x70 was mounted to a Bogen 501 head on an older Bogen/Manfrotto 3246 tripod. I've since replaced the original single extension leg insert with a two-piece leg insert. With the two piece leg extension I get the needed height and this tripod is identical to the Manfrotto 028. In fact it has the number 028B engraved on the column. A FarSight adapter is mounted to the QR plate. I interchanged the Fujinon 16x70, Fujinon 10x50 and Oberwerk Ultra 15x70, with FarSight posts already inserted in these three binocs.

The Nikon 18x70 was mounted to a Bogen 128RC head on a Bogen/Manfrotto 3011 tripod. the Nikon tripod adapter is mounter to the 128RC QR plate. The Nikon 10x70 was swicthed out using the same Nikon adapter. The 128RC head is nearly identical to the older Bogen 3130 head.

Both the large tripods have center column elevators. The 3011 center column must be raised/lowered by holding and hand-adjusting while loosening the locknut.

The WO22x70 movement was very smooth and well balanced. The WO vertical post on a sliding balance bar provides the ability to center the mass over the tripod. I've got the tension on this head set just right.
The Fujinon 16x70 was smooth and balanced, but a bit tighter than the WO setup.

I had the Nikon 18x70 on the 128RC head tightened down too tight in the altitude adjustment. I fiddled with it several times, but would make it too loose so the binocular would drift, or too tight making vertical adjustment difficult. Had no affect on viewing, but altitude tilting was not as easy or smooth as the 501 heads.

edz

#14 ScumotheUniverse

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Posted 17 October 2010 - 10:38 AM

Employing not just a little reductionism in converting all of this data to the world of consumerism I hope that WO production capabilities can keep up with the sudden uptick in orders for the 22X70 APO. And will Optics Planet ever sell their one specimen of the 18X70 Astroluxe? BY the way does WO manufacture in Taiwan or mainland China?

Thanks to EdZ for his continued hard work (or play) that we all benefit from.

#15 RichD

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Posted 17 October 2010 - 10:51 AM

Seems the nikon 18x70's main advantages are the slightly wider AFOV and the more nose-friendly eyepieces. I have to say (without ever having tried them I hasten to add)That I would be disappointed with that much field curvature in a bino that expensive. Just shows what an absolute bargain the fuji 16x70 really is.

Sounds like a similar amount of curvature to the fuji 7x50 FMT.

I wonder if the 7x50 prostar has a different optical construction to it's bigger brothers, the 10 and 18x70.

#16 pcad

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Posted 17 October 2010 - 11:24 AM

dOP,

You asked which version Nikon 10x70 is being tested. Truth is that I'm not sure. They came from either Australia or New Zealand via eBay about a year ago. The seller said the previous owner told him they were the Astrolux model and that he had no reason not to believe him.

This 10x70 has no obvious "astrolux" designation on them and lacks the red ring at the objective end. They came with the same batwing eye guards as the 18x70s. The case is round at the sides as opposed to box-like for the 18x70s.

Probably the only way to find out which 10x70 model it is for sure is to check the serial # with Nikon. I've never done this and Ed has the serial # at this point.

There was a detailed discussion about what constitutes an astrolux a long time ago. I'll see if I can find any hints.

#17 EdZ

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Posted 17 October 2010 - 11:30 AM

Based on comments found in older Minireviews of the Nikons 10x70 and 18x70, there seems to be sufficient documentation to state, neither of these binoculars have ever used any ED glass. The red ring around the 18x70 does not signify any special glass.

There is quite obvious false color in both the 10x70 and 18x70, more-so in the 18x70 as would be expected from the higher power. On both the Moon and Jupiter, while it was sometimes possible to get an on-axis view without false color, it was nearly impossible to hold onto it. More often than not, the view on-axis had false color. The view off-axis always had false color. There is much more significant false color off-axis than on-axis.

The 18x70 I'm using has a red ring around the objective. The 10x70 does not. Rick from Tokyo documented the explanation of these markings and the lack of ED glass. Refer to the mini-reviews.

10x70 is Serial # 431548. The diopter adjustments have lines engraved in half increments and the marked range goes from +2 to -4

18x70 is Serial # 830715. The diopter adjustments have lines engraved in full increments and the marked range goes from +4 to -4

My Prostar 7x50 is S# 224854. It has a red ring around the objectives.

From the braced prism housing back to the eyepieces, the housing construction is identical in all three. The Prostar simply has shorter barrels and smaller objectives.

There is considerable curvature in the Nikon 18x70. Therefore, I question whether the design employs a field flattener. If it does, I'm not seeing significant results of flattening (removing curvature). The curvature in the 18x70 is moderately pronounced, more-so than in the Fujinon 16x70 which does employ a field flattener.

The off-axis aberrations in the Nikon reduce the outer field sharpness of the 18x70, by a considerable amount. Previous comments that I have read regarding the excellent edge sharpness of the 18x70 are flat out incorrect. All I can assume about those comments is that they were not based on measures, but more likely based on subjective opinion, in some cases without comparison to another binocular. There are other older reviews that do mention the off-axis lack of sharpness. It is quite easy to see the lack of outer field sharpness in the 18x70 in measured comparisons to like sized binoculars.

Nikon 18x70 resolution is excellent. Extent of fov is excellent. Even with the low profile rubber eyecup folded down, eye relief is short for eyeglasses, so some of that fov is lost to view.

More tiny craters were seeen on the Moon using the Nikon 18x70 than with the Fujinon 16x70. But there was no noticable improvement in contrast or resolved image other than that gained by the slight increase in image scale. For objects that were large enough to view at both scales, I could not say that I was able to see more detail in the Nikons. I was able to see far, far more detial in the WO22x70, and I attribute that to image scale.

There was a small ghost image of the Moon seen in the Fujinon 16x70. I'm pretty sure this was a reflection off of my eyeball shining back into the concave eyepiece. As I moved my head around, I could make the ghost image move around. I do not recall seeing that in the Nikon.

edz

#18 Andresin150

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Posted 17 October 2010 - 11:37 AM

Now, that is an excellent technical review, thanks EDZ for that valuable info

#19 EdZ

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Posted 17 October 2010 - 12:20 PM

I wonder if the 7x50 prostar has a different optical construction to it's bigger brothers, the 10 and 18x70.


The Nikon Prostar 7x50 has ZERO curvature, and I do mean ZERO. That binocular definitely employs a field flattener to its best advantage. No other binocular I have seen even comes close. The closest binoculars to the Prostar in lack of outer field total aberration, all exhibiting very fine image quality, are the Takahashi 22x60, Pentax PCF WP 16x60, Nikon SE 12x50 and the Celstron Regal 8x42 roof. These all range from more than double to triple the outer field aberrations as that measured in the Prostar.

edz

Memory is a funny thing. I went back to my recorded data on this and found there IS measurable curvature. However, both total aberration and curvature are very small.
edz

#20 davidmcgo

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Posted 17 October 2010 - 02:42 PM

My 10x70 Astrolux does have same red ring around the objective as the 7x50 Prostar. it also has a red border to the hinge cap with the serial number. Markings on that are:

Nikon
622794
TP

It behaves as you describe the 7x50 Prostar, no field curvature at all. So your 10x70s without the red ring are likely the tropical model.

Dave

#21 EdZ

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Posted 17 October 2010 - 03:06 PM

regarding the markings on the Nikons

quotes from the archives

I´ve got now an offical statement from Nikon Germany.
They have asked an expert in the Netherlands.
Here is his statement "These Binos have no ED glass this red line is for design point of view to seperate from other Marine Bino to create a high grade image"

The 18x70 does NOT have ED (SP?) glass. I verified this with a Nikon engineer at the Tokyo Photo Imaging Expo 2 years ago. The Japanese catalog also indicates as much.

Now this may sound like heresy but I am even willing to guess that Nikon does not use any ED or low dispersion glass in ANY of its binoculars. Nowhere in the Japan catalog or on the Japan web site do they say they do, unlike with the field scopes.

All of these Nikon IF or SP are using the SAME objectives.
The differences between their objectives are only multicoating (red-green)for SP or coating (blue)for IF.
However the SPs are the better choice, because they have the
field flattener lenses and a superb multilayer coating really free of any ghost images.

the stripe itself doesn't stand for anything. It is just a cosmetic marking to let consumers know it is not an HP model. One more point. After studying the Japanese catalog and web site today I think the ONLY REASON Nikon considers the 7x50/10x70 "designed" for starwatching is because of the 7mm exit pupil.

The SP designation means "Special Performance" and has nothing to do with the red stripe around the objective. The red stripe indicates the presence of a field flattener lens.

From all outward appearances the Nikon 7x50/10x70HP and 7x50/10x70SP series look and are marked identical except for the red stripe. Unless you weighed or looked through them you cannot tell the difference. The only confirmed difference in the optics is the field flattener lens in the red stripe series.

In the current Japanese Nikon catalog, the SP binoculars are grouped together and are specifically recommended and designed for star watching. The 18x70 IF WF is together with the other "marine use" 7x50 and 10x70 IF HP binoculars. Starwatching gets a secondary mention.

All these comments can be found thru the minireviews.
edz

#22 KennyJ

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Posted 17 October 2010 - 04:20 PM

Thanks for all your painstaking research , reviews and report work with regard to all these Nikon models , Ed .

I would have thought the latest Nikon EDG models may contain some kind of special glass , but of course have no evidence of such .

Not least , I'm pleased you've finally shed some light on to the hitherto longstandingly mysterious Red Stripe mythology .

Somehow I just new those models never looked right standing on a dining table next to a bottle of HP sauce !

Kenny

#23 hallelujah

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Posted 17 October 2010 - 04:32 PM

I would have thought the latest Nikon EDG models may contain some kind of special glass , but of course have no evidence of such .

Kenny


Kenny,

Nikon 2008 Birding Optics Catalog:

"EDG is the first birding binocular to harness the optical superiority of Nikon's highly acclaimed ED (Extra-low Dispersion) glass to push limits of optical performance. Coveted by the world's greatest photographers in Nikon's legendary Nikkor lenses, this exclusive glass was developed to eliminate chromatic aberration, which occurs when light rays of varying wavelengths pass through optical glass. Nikon EDG binoculars offer the same results to the world's most serious birders--high contrast images that are extremely bright, razor sharp and free of flare".

http://www.nikonspor.../EDG/index.page :)

#24 KennyJ

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Posted 17 October 2010 - 04:57 PM

Thanks for that , Stan !

Far preferable to just the link :-)

I've read that before , of course , but as I said , have no personal EVIDENCE .

Someone will just have to loan EdZ their prized Nikon EDG !

Kenny

#25 Rick

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Posted 17 October 2010 - 05:08 PM

Kenny,

No doubt the latest EDG birding binos have ED glass. Several of my statements Ed listed above involving the 18x70mm were made years ago prior to the EDG release.

Re: the field curvature and rolling globe effects, I can recall seeing and being put off by the FC the very first time I tried a 18x70. Eventually though after extended use my eyes learned to accomodate it and I was no longer disturbed by it. I never recall noticing the rolling globe but as we all know, that is THE ONE effect that is very user physiology dependent.

For me, it is the new Swarovision that exhibits the most pronouned rolling globe, yet by any other measure it is still probably the best roof prism bino on the market. I would think for some it might be safe to say the same about the Nikon 18x70.

As for the Fuji vs. 2x more expensive Nikon value debate, it is a moot point if your face does not work with Fuji. If you don't get on with the Fuji but still want a high quality NAME BRAND 70mm nitrogen-purged bino, the Nikon is the only choice available. Simple as that.

Finally, I am surprised the 4kg WO22x70 works well on the Manfrotto 501 head. The normal rule-of-thumb as been to choose a head with a load capacity at least 1.5x-2x the weight of the bino. But now I see it can be more easily balanced over the head by the sliding mounting post. It's a sharp-looking bino too BTW, and I am happy to see there is finally an OEM that has put the needs of astronomy hobbists first with its design. I hope Mike buys one and will bring it over for me to play with! ;)


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