If you keep your eyes open you might pick up an EII like this.
http://www.ebay.com/itm/Nikon-Premi...=&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
-
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Does Nikon use ED glass in the SE and EII? (1 Viewer)
- Thread starter Sandy Leng
- Start date
http://www.ebay.com/itm/Nikon-Premi...=&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
brocknroller
porromaniac
Mmm... I thought that was pretty much what I said, but I guess you said it better! I would have have made that fine distinction you did, but I didn't think there are that many roofs without internal focus these days. Thanks for chiming in and for including the SV EL.
<B>
brocknroller
porromaniac
I used the term "microscope" partly because of a saying, which apparently doesn't cross the pond, of putting something 'under the microscope,' which means to scrutinize it closely, and partly because Henry often boosts the image to 56x in his tests, which is a high power used in microscopes rather than binoculars. So it was intended as a double entendre.
I think the Porters use a group of birders for their tests, at least they did for the first midsized binocular tests that were published in Bird Watcher's Digest a few years back. They said how some models fit some of the testers' glasses and not others. At that time, the only model that had enough ER for all the four-eyed testers was the Celestron 8x32 Noble. Like cream, the alphas always rise to the top in their reviews.
Yes, there are lucky dogs out there who do not see CA. I had hoped that it also meant that they couldn't see the subtle difference in shades of color that those of us who are sensitive to CA see, but according to Bob, he can see the subtleties but not the CA, which only proved that there is no fairness in the universe.
Yes, I've tried the old Actions with the aspheric elements and found it caused "RB" while panning.
Not sure who was dissing your idea on that thread, although Dennis was in his "Roofs are Superior to Old Technology Porros" period at that time, but he has now "seen the light" and owns both an 8x32 SE and 8x30 EII and sings their praises. But that is subject to change without notice.
I agree that roofs have come along way from my un-phased coated Japanese-made Nikon 8x36 Sporter 1, which was decent, but nowhere near as "sharp" or bright as my 501 SE. However, those incremental improvements in roofs over the years have led us to the $2K+ point now with alphas.
The saving grace, IMO, is that some of that technology pioneered on the top shelf has made its way down to lower priced roofs, which now carry standard features such as phase coatings, silver or dielectric coatings, twist-up eyecups, internal focus, and even ED glass has started to seep down into the affordable range with Nikon, Bushnell, Zen Ray, Hawke and others. Of course, some porros had ED glass decades ago.
I had suggested before Henry came up with the focusing element explanation that the cause of excessive CA in roofs in the 1990s might be due the changeover to lead-free glass, but that went over like a lead balloon. (o)<
I did actually find some supporting evidence in two reports from Ohara that their early attempts at making lead-free glass were not on par with their optical lead glass, because they could not find the right combination of lead substitutes that were also inexpensive enough not to significantly raise the price of the new glass, but no evidence that any of those early batches of subpar lead-free glass were ever used in binoculars, but one report did say that early lead-free glass was used microscopes and that the CA could be seen at the extreme ends of the spectrum when specimens were photographed.
As birders, we forget there's a whole world of microscopy out there, and since microscopists pump up the power much higher than birders do in binoculars, if the glass type is causing more CA, it will be more easily noticed in microscopes.
I also based my hunch on my observations that when Nikon changed over to lead glass in the HGL, the image showed more CA, than the original lead glass HGs, and also because the EIIs with lead-free glass also showed more CA than the SEs with lead glass. In addition, not long after the introduction of lead-free glass in roofs, complaints about CA started cropping up, but as Henry later pointed out, that was the same period of time when internal focusers started becoming standard fare on quality roofs.
So as you and Henry have both proposed, internal focusing elements in roofs do seem to be the culprit since I can still see more CA in non-ED contemporary roofs even now that lead-free glass has been perfected.
Since I'm sensitive to CA, the only roofs I find suitable are ones with ED glass. Those choices are somewhat limited in the $500 or under price range, but they are growing.
<B>
Last edited:
Hello Brock
The phrase 'to put something under the microscope' does cross the pond, when used in its entirety.
I am not convinced that boosting the full aperture image with a magnifier is all that relevant given that the human eye is unable to use the resolution of the full aperture. Yes it does help determine the full aperture resolution, but that is not usable.
As you well know, in normal use, the eye's pupil stops down the aperture, so on a sunny day perhaps only 2mm of the exit pupil is used. What matters is the contrast at the scales that the human eye can resolve. This can be gained from the MTF curve for the binocular at appropriate spatial frequencies. I suspect you know about the Modulation Transfer Function. It is rather like old TV camera lenses which did not have great resolution, but they did have high contrast at spatial frequencies relevant to the low resolution output device i.e. the TV. Interestingly lens manufacturers do often provide an MTF plot, albeit a theoretical one. I am not sure how the MTF plot at spatial frequencies of interest would vary with effective aperture, I suspect not much if we restrict our selves to sensible effective apertures, atlhough that is speculation.
I do agree with you about CA and internal focussing roof prisms binoculars: non ED ones are awful.
"As birders, we forget there's a whole world of microscopy out there, "
http://www.leifgoodwin.co.uk/Fungi/1__DSC6370%20Spores%20lactophenol%20cotton%20blue%20x100.jpg
I am more of an amateur microscopist than a birder. The above are spores from a cup fungus, stained so as to show the surface ornamentation. I really need a better camera, as taking photographs at x1000 strains the one I have.
The phrase 'to put something under the microscope' does cross the pond, when used in its entirety.
I am not convinced that boosting the full aperture image with a magnifier is all that relevant given that the human eye is unable to use the resolution of the full aperture. Yes it does help determine the full aperture resolution, but that is not usable.
As you well know, in normal use, the eye's pupil stops down the aperture, so on a sunny day perhaps only 2mm of the exit pupil is used. What matters is the contrast at the scales that the human eye can resolve. This can be gained from the MTF curve for the binocular at appropriate spatial frequencies. I suspect you know about the Modulation Transfer Function. It is rather like old TV camera lenses which did not have great resolution, but they did have high contrast at spatial frequencies relevant to the low resolution output device i.e. the TV. Interestingly lens manufacturers do often provide an MTF plot, albeit a theoretical one. I am not sure how the MTF plot at spatial frequencies of interest would vary with effective aperture, I suspect not much if we restrict our selves to sensible effective apertures, atlhough that is speculation.
I do agree with you about CA and internal focussing roof prisms binoculars: non ED ones are awful.
"As birders, we forget there's a whole world of microscopy out there, "
http://www.leifgoodwin.co.uk/Fungi/1__DSC6370%20Spores%20lactophenol%20cotton%20blue%20x100.jpg
I am more of an amateur microscopist than a birder. The above are spores from a cup fungus, stained so as to show the surface ornamentation. I really need a better camera, as taking photographs at x1000 strains the one I have.
henry link
Well-known member
I suppose moving objectives have the inherent disadvantage of straying from their optimum position relative to stationary baffles as the lens moves back and forth, but I've seen lots of poor baffling in fixed objectives. In the 8x30 Zeiss Dialyt my money is on the retaining ring behind the objective lens as the culprit in the glare (see photo below). It's not narrow enough to act as a true baffle and it's just the sort of metal surface that would reflect strong glancing light back toward the eye, which would appear right at the edge of the exit pupil. It may be hidden behind the baffling cone at some focusing distances but become exposed at others. You should be able to locate the source of the glare in any binocular by using a magnifier to examine the innards through the eyepiece when the glare is occurring.
Henry
Attachments
Almost off topic by now, but although the SE does not have an ED glass objective, it might as well as far as I can tell. Other binoculars that might be simple-theoretically expected to be as good, aren't. For example, my 7x50 Fujinon FMT-SX which should have every optical advantage of the SE and then some, shows color fringing rather badly. Go figure. If you are bothered by CA in the SE, you will be bothered by CA in the Zeiss FL too. That would be a serious level of concern for CA, like Cotton Mather was concerned about witchcraft.
The SE might well be rejected for its quaint mechanical Porrosity: unadjustable eyecups causing blackouts for some users, a slow acting and narrow focus knob, focus grease that gets stiff in the cold, and slight vulnerability to water and the elements. But for color error, or in fact for anything about the optical quality, I don't think so.
Ron
The SE might well be rejected for its quaint mechanical Porrosity: unadjustable eyecups causing blackouts for some users, a slow acting and narrow focus knob, focus grease that gets stiff in the cold, and slight vulnerability to water and the elements. But for color error, or in fact for anything about the optical quality, I don't think so.
Ron
Bob, re waterpoofing, my point was that for a bin which is continuously (say often a year or more at a time) in such a part of the world as this wp. is essential, unless one can give the attention needed to protect from fungus. This means keeping it in an airtight "dry box" all the time it's not used and reactivating the desiccant material regulalry, or a in "hot box" w. a constant supply of elecricity. In any other conditions, yes, wp. may not be needed.
I tried another Swaro 8.5x42 today, and it was completely different from the one I tried last week. In the first one the outer field region was very strange, for want of a better description it was distorted and soft, and there was obvious colour fringing near the centre, increasing towards the edges. I noticed these issues straight away, and I was rather surprised. The one I tried today was quite different, the field edges were very good, and colour fringing was well controlled. It was certainly a match for my 8x32 SE, and probably surpassed it. I can only assume that the first Swaro was defective, perhaps out of collimation, and had I tested each optical assembly separately, it would surely have shown itself in only one of them.
On the same theme, I tried both Swaro 8.5x42's on an overcast day, with low light levels, typical of English Winter, and Summer, and Spring and Autumn. It is worth bearing in mind that on a dull day the pupils dilate, and use more of the objectives as the effective aperture is larger. This means that you are giving the instrument a tougher workout, since as is well known, aberrations increase with effective aperture, assuming a fixed focal length. Perhaps in bright light, eyepiece aberrations dominate.
I checked the popular albinos site, and their description of CA testing. As far as I can see they do not account for this effect. And that might also apply to other defects. I wonder how much variation there is in the IQ as the effective aperture varies, given that the off axis image quality is determined by aberrations in the objective and the eyepiece? It is interesting to see that a supposedly objective (no pun intended) test is in fact far from complete.
Having seen Henry's photos linked to earlier, it looks to me as if a variation of that would provide a more objective (pun not intended) test, using a range of effective apertures to similar different usages i.e. sunny day, dull day, and image at field centre and off axis.
brocknroller
porromaniac
Indeed, this was the case yesterday when I went for a walkabout with my 8x30 EII. Normally, I use this bin in my backyard and in nearby woods where the extra wide field and huge sweet spot make it ideal.
However, on that dim and dreary day, the image was "mushy" to use Henry's term. Not just reflecting "reality" as dennis put it, but my increased entrance pupils brought out the worst in the bins and in my eyes.
I normally have to bring an object to the edge of the field to see the field curvature with the 8x EII because of the large sweet spot and gradual fall off at the edges, which my eyes can accommodate in good light. Due to fog, thick cloud cover, and a low hanging sun, the light levels in the mid-afternoon were like twilight, and I could see the field curvature and combined with the pincushion, which is more visible while panning in an open environment. I could also more CA than usual because I had the gray sky in the background while looking for bluebirds in the nearby trees.
I have astigmatism, primarily in one eye and the beginnings of a cataract in the other. In bright light the effects of those imperfections are minimal, but in dim light they are quite noticeable.
The hodgepodge of aberrations and distortion from the optics and the imperfections in my eye made for an unpleasant viewing experience. Plus, I didn't see any bluebirds! They were lost in the "fog".
Brock
As I stated in the preceding post, or were you referring to aberrations in the cornea?
I was using effective aperture as the term for the aperture of the combined optical system, including the pupil, as opposed to the real aperture of the instrument alone. I thought it was clear, but maybe not. |=)|
But yes, eye imperfections matter too, though I do not know the degree to which those matter in a typical person. I had some splinters scraped out of a cornea, and that cannot have helped. The splinters caused astigmatism until they were discovered by an optician.
brocknroller
porromaniac
Both. As Henry showed in his review of the 8x56 FL, when you "stop down" the aperture with smaller entrance pupils on a sunny day, the view improves:
http://www.birdforum.net/showthread.php?t=81438
And also due to more of my corner being exposed when lighting is poor, which brings out the imperfections that I normally can ignore. The exceptions are floaters, which are more noticeable in bright light and particularly annoying while observing the moon and planets. I remember during the Mars opposition of 2003, I thought I saw Schiaparelli's "canali" but they were just floaters, which I had to keep rolling my eyes to float out of the way.
<B>
Yes, I'm well aware of that, I even said earlier that the view improves as the effective aperture reduces. Maybe I should write very slowly in big letters, or use sempahore. |
| Actually I would argue with your statement. Experience tells me that on a bright sunny day contrast is very high, and some binoculars show very high chromatic aberrations. Even my 8x32 SE shows more than I like in those conditions. A duller day gives a better image. I suppose it depends how you define 'improves'. And in fact I would argue that the view improves. It stays the same. Same cows, same grass. The image might improve though. (I can be argumentative too you know.)
It is all very well having the 'perfect instrument', but unlike you (and Henry I assume) I am not superman, so a more conventional instrument is fine for me. I have not read the link, but I assume the 8x56 has longer focal length objectives, so for a given effective aperture (pupil size if less than 7mm), it should have better performance than an 8x42 binocular for example. You know that of course, being superman and all that. Psst: How's the fight against crime going? |
|normjackson
Well-known member
Before answering that Brock will demand to know whether you are Sherlock Holmes or Professor Moriarty...Psst: How's the fight against crime going? |
How about Barratt Homes?
brocknroller
porromaniac
Yes, I'm well aware of that, I even said earlier that the view improves as the effective aperture reduces. Maybe I should write very slowly in big letters, or use sempahore. |
Actually I would argue with your statement. Experience tells me that on a bright sunny day contrast is very high, and some binoculars show very high chromatic aberrations. Even my 8x32 SE shows more than I like in those conditions. A duller day gives a better image. I suppose it depends how you define 'improves'. And in fact I would argue that the view improves. It stays the same. Same cows, same grass. The image might improve though. (I can be argumentative too you know.)
I was just parroting Henry's findings (although I do agree with him on this matter). But you can duke it out with him. I'd like to see another Tech Wars!
I'm referring to a thread we had about four or five years ago when Henry faced off with Edz from Cloudy Nights and a couple other optics experts in fight to the arc second finish over what I have no idea. There was a point in the debate at which my convulsions collapsed. I found it even more confusing than the first presidential debate. It is all very well having the 'perfect instrument', but unlike you (and Henry I assume) I am not superman, so a more conventional instrument is fine for me. I have not read the link, but I assume the 8x56 has longer focal length objectives, so for a given effective aperture (pupil size if less than 7mm), it should have better performance than an 8x42 binocular for example. You know that of course, being superman and all that. Psst: How's the fight against crime going? |
The crime fighting has picked up markedly during the recession but has been on the rise since Rudy left office, but my alter ego, Clark Kent, has been so busy writing about the Meltdown, the bailouts, the stimulus funds, the housing crisis, the job numbers, the shale plays, and the gridlock in Washington for the Daily Planet, that I've had to ask Wonder Woman to fill in for me on occasion like recently when she put down the Tea Party rebellion single handed. All that strength and a 24" waist, no wonder Lois is jealous.
<B>
