Is it me, my eyes, or what? (1 Viewer)

[Troubador]

Hi Lee

I'm actually on Mull this week, so similar to your usual locations. I have had a few sightings of them in the sea just off shore but only a brief glimpse of one fully out of the water...

Plenty of sea birds though!

Steve

Keep at it Steve, at this time of year there is an excellent chance of seeing a female with one or two cubs. And since they need to come to shore regularly to warm up (usually bringing a larger than average catch to fuel this) if you keep at it you will hopefully get more out of water sightings.

Hope you get calm waters when it is easier to see what they are doing.

Good luck!

Lee

 

[paddy7]

Very akin to scanning slopes for such birds as Chukars or Rock Partridge; it involves a level of concentration from which you need the occasional break!

 

[stiv674]

Keep at it Steve, at this time of year there is an excellent chance of seeing a female with one or two cubs. And since they need to come to shore regularly to warm up (usually bringing a larger than average catch to fuel this) if you keep at it you will hopefully get more out of water sightings.

Hope you get calm waters when it is easier to see what they are doing.

Good luck!

Lee

Thanks for the info, unfortunately I only have one day left...

A bit of luck and patience are required, actually quite a bit of patience

That goes for driving on Mull as well... sorry for going off topic somewhat.

 

[Troubador]

Thanks for the info, unfortunately I only have one day left...

A bit of luck and patience are required, actually quite a bit of patience

That goes for driving on Mull as well... sorry for going off topic somewhat.

We have seen Otters at all stages of the tide but the closer you are to low water the better. I guess because the water column they need to dive through is shorter so uses less energy. Sea-weedy places are favoured because they like to surprise their prey amongst the weed rather than chase their prey through open water. They are a bit like a Sparrowhawk rather than a Peregrine in this respect.

And parking on Mull can be difficult depending where you are. Loch Spelve in the south is usually good for Otters.

Lee

 

[stiv674]

You mean I've been doing it wrong all this time! I have been doing the pot luck approach...

I have driven past Loch Spelve a few times on the rickety road to Lochbuie where I'm staying. Maybe I'll have a proper look along there tomorrow.

My fifth time to Mull, maybe somewhere different next year, any suggestions?

Thanks

Steve

 

[Troubador]

You mean I've been doing it wrong all this time! I have been doing the pot luck approach...

I have driven past Loch Spelve a few times on the rickety road to Lochbuie where I'm staying. Maybe I'll have a proper look along there tomorrow.

My fifth time to Mull, maybe somewhere different next year, any suggestions?

Thanks

Steve

Replying by PM.

Lee

 

[Patudo]

I can see all the other things, brightness, contrast, colour saturation etc. But not resolution.

Come guys, help me out here.

Ron

Hi Ron.. It seems the technology and manufacturing to make a very sharp pair of binoculars was achieved some considerable time before modern coatings reached their current level of perfection. Others here (Hermann etc) have praised the sharpness of eg. the old Zeiss porros, and my own experience seems to bear this out. The center field resolution of both examples of the Leitz Binuxit I have recently handled, for instance, stood comparison with that of the 8x32 FL (to my eyes anyway), and the Swift 7x35 I own is also very sharp. If only it were possible to upgrade the coatings of that generation binoculars to modern standards, I think they would be terrific.

Regards,
patudo

 

[Binastro]

I would treat the following with caution as I don't trust internet information.

Veronica Seider born Stuttgart 1951, a dentist, was tested in October 1972 when she was still a student.

Her visual acuity was reportedly around 20/2 at that time.

She could distinguish people at 1 mile and judge their distance.

She claims to see the 3 colours in a television set rather than a combined image.

I have not seen an official paper on this study.

Perhaps someone here has seen this or could find this study.

I did see a report several years ago that a German woman could detect tenth magnitude stars in an indoors test environment.
That would be magnitude 9.5 to 10.5, say magnitude 9.6 or fainter.

In an outside environment the best that I have seen reported was about magnitude 8.3 at altitude, and a woman observer regularly sees magnitude 7.9 stars at star parties.
She has also seen Mercury with the Sun above the horizon.

I have seen Mars with the Sun above the horizon, but never Mercury.

 

[Binastro]

Re. Post 68.

I don't think that seeing the 3 colours on a 1972 T.V. set is that difficult.
It depends how near the screen one is.
With exceptional vision it may be that the normal distance shows the three colours.

To be able to judge the distance of a person at one mile against a distant background would I think need 20/3 or possibly 20/4 vision if one was stationary.
However, if one moved a bit sideways perhaps 20/5 or 20/6 might be sufficient.

To distinguish detail in a person at one mile needs more information.
What kind of detail?
Is it say a member of ones family?

It would be good to see if there is a proper scientific study of this lady's vision.

If indeed this lady had around 20/2 vision it would be nice to see a study of another person found with 20/3 vision.

One explanation could be that instead of the fovea being concentrated in 2 degrees of central vision, a person with Super sight has the concentration in only 0.5 degrees of fovea, or at least a very concentrated central fovea.
The Moon is 0.5 degrees across and even with normal vision much detail can be seen.
With a very concentrated central fovea of only 10 arcminutes, very fine detail could be seen.

 

[giosblue]

Hi Ron.. It seems the technology and manufacturing to make a very sharp pair of binoculars was achieved some considerable time before modern coatings reached their current level of perfection. Others here (Hermann etc) have praised the sharpness of eg. the old Zeiss porros, and my own experience seems to bear this out. The center field resolution of both examples of the Leitz Binuxit I have recently handled, for instance, stood comparison with that of the 8x32 FL (to my eyes anyway), and the Swift 7x35 I own is also very sharp. If only it were possible to upgrade the coatings of that generation binoculars to modern standards, I think they would be terrific.

Regards,
patudo

I'm beginning to think that top binoculars are sharper than most peoples eyes can detect. Maybe when the magnification increases differences in resolution would be more apparent. But for 8x and 10x, I have to admit, I'm struggling.

 

[typo]

Unfortunately, the claims for Veronica Sieder's visual acuity I've found on line are far too vague to have any value. The details, such as the are, could be interpreted as anything between a very respectable 20/10 and a nonsensical 20/0.5. I'm sure to lauded in this way someone must have produced verifiable exceptional results, but if so, I can't find them.

David

 

[adhoc]

Searching on the internet, using Google, and words and combinations such as her name, "visual acuity", "university", "stuttgart", "1972"... did not bring up or indicate the source report, with me using English. Maybe a member interested in this (or in helping out!) and good enough in German might like to try?

 

[Binastro]

Because of patient confidentiality the results of medical tests of eyes are only normally available to medical practitioners.

Sometimes papers are written and published in medical journals one to ten years later.
The results sometimes appear in medical books.

Google is pretty useless.

The astronomers with noted excellent eyesight with whom I have spoken to, don't normally discuss their eyesight because of disbelief from fellow astronomers.
This includes Stephen O'Meara and my fellow Saturn observer Paul Doherty, artist including birds, astronomer, observer and guitarist, who unfortunately passed away at 50. At least his beautiful accurate paintings survive him.
According to Patrick Moore, Paul could see Jupiter's moons without optical aid.
George Alcock had similar problems with disbelief, as did I, and my eyesight is very average, although I could see faint objects better than most.

Visual acuity Navy Pilots 1986 Morris and Hamilton.
163 pilots, 145 flying F14 Tomcats.
The average high contrast visual acuity score was 20/8 Snellen.
No pilot was worse than 20/15.
(Pilots average age maybe 30?).

Spectacled and older pilots were worse than others.
Spectacles were only corrected to 0.25 dioptre and 20/20 standard, and the pilots performance would be better with optimal correction.
This is what I have found. My spectacles are made to 0.125 dioptres even with my old poor eyes.

WW2 fighter pilot study 250 pilots 1947 paper.
94% better than 20/15 mean 20/13.

Another old study 90% better than 20/15.

Modern jet fighter pilots probably need better eyesight than those thrown into battle in WW2, although one Finnish ace had very fine sight.


With Veronica Seider, perhaps she would give permission for the results to be published when she was tested at about age 20.
Or maybe Stuttgart university would give permission.

 

[adhoc]

About the German, maybe I should clarify:
I would like to see the relevant document/s furthest back available to us,
but it is really not possible to accept the story as conveyed with regard to that acuity!

 

[typo]

Binastro,

Thank you alerting us to the work of Morris and Hamilton. Interesting stuff! It seem the visual criteria to enter the Navy air combat selection program was only 20/20 but the operational performance attrition meant that successful graduates commonly had binocular VAs around 20/8. No wonder the was a need to re-examine the visual entrance criteria.

It is surprising that, even at that time, the US Navy only corrected eyesight to the 20/20 standard. That was the reason I gave up using the high street optician chains and switched to an independant and immediately improved my binocular acuity by almost a factor or two. I wouldn't be at all surprised if some of those Navy pilots chose to do the same thing, rather than risk their jobs.

One of those sensational online claims for Veronica Sieder was her visual acuity was 20 times better than average. So 20 times better than the average 20/15 would be 20/0.75. If we assume her eyes were totally free of refractive errors, then her pupils would have to be around 25mm diameter in normal daylight and have about 100 times the usual density of receptors in her fovea. On the other hand if her eyesight was 2.0x, not 20x better than average and her VA was 6/2 not 20/2 then the rest of the details start to make sense.

David

 

[Binastro]

The problems with the reports of Veronica Seider is that journalists have no knowledge of what they are reporting.
Even so called science journalists in top newspaper get it totally wrong. However, the Daily Telegraph science reporter usually got it right, even with difficult stuff.

Sky and telescope reports are usually very accurate.

I came across a reference to an unnamed German who could detect 10th magnitude stars in a controlled environment. I now assume this was Veronica Seider.

Without the actual test results one simply does not know what her visual acuity was.

With regard to my conversations over dinner with Stephen O'Meara and on the phone with Paul Doherty both made clear that their eyesight was not as good as when younger, and that their eyesight varied from day to day.
It is not fair to ask a person to produce their best VA and faintest star visible just at the spur of the moment, as with an athlete, performance varies.

Although the reports of Veronica Seider vary, I would think that her vision was better than 20/6.
I think that it is likely one or more of the F14 Navy pilots had 20/5, maybe 20/4.5 vision.
The general population is vast compared to either Navy pilots or astronomers, so I think there will be a few individuals in the world whose eyesight is better than the best astronomer or pilot.

I worked for two years on a paper to have it rejected by the referee whose eyesight was clearly defective. He said I had floaters in my eyes, which I didn't at that age. He clearly had.
So I just got fed up with the British old boys rugby playing club and went to the U.S.
They published it immediately because they understood what I had seen and what I was describing.
They used this information to explain some different sightings that seemed difficult to understand.

I had the same with other papers and just went elsewhere where the referee understood exactly what I was saying.
It doesn't necessarily need exceptional eyesight to be good observer. Just a lot of experience and care.

I have a weekly delivery from a person I have known for years. He arrives in a white Ford Transit.
A car just arrived and I saw someone get out. I was very surprised that shortly afterwards my doorbell rang.
My delivery driver appeared. Even though I had seen him get out of his car, which I didn't know he had, I had not seen him.
He was invisible to me even though I had clearly seen him.
Eyes and brain are really quite strange.

As to the Navy pilots, if they need corrective glasses as they get older, if they can detect 1/16 dioptre changes and 1.25 degrees astigmatism angle changes that is what they should get both as to the prescription and the actual glasses made to high accuracy.
I can detect 1/8 dioptre and 2.5 degree increments repeatedly even now, and my eyes are poor nowadays.
The recent glasses I got clearly improve my vision and allow me to watch T.V. twice as long before my eyes get too tired. There were only subtle changes from last year and a normal optician would not have bothered to correct the error.

 

[typo]

......
Although the reports of Veronica Seider vary, I would think that her vision was better than 20/6.
I think that it is likely one or more of the F14 Navy pilots had 20/5, maybe 20/4.5 vision.
.......

I've not managed to find any studies directly comparing monocular with binocular acuities but, my experience at least, is the latter is usually a little better, so potential could exceed the Nyquist limit by a small margin. Without the actual raw data we can only speculate about what the actual values were in either case might have been, but for Veronica Seider I see no need to surpass 20/6 to explain the achievements mentioned online. The only result shown for the pilot acuity is an acuity distribution curve which is discontinued a little before reaching 20/6.5. Normally that would indicate the limit of the measured values.

There was another parameter in a different study by the same team which I think was rather interesting. One of the distinguishing results was that the navy combat pilots where significant less myopic in the dark than their helecopter counterparts. This presumably helps with landing high speed jets on an aircraft carrier in the dark. I guess these differences might be a distinguishing parameter for other vision based nocturnal interests?

David

 

[Binastro]

Landing fast heavy jets on aircraft carriers in the dark is I think partly black magic.
It is probable that more than good eyesight is needed.

With faint vision experienced observers report that stacking of the eye's images is probably involved, as the faintest objects seen are when relaxed but looking at the same place for several seconds.

I can't see how stacking several images could be used during the day for high resolution, but I wonder if the brain can do this somehow.

Regarding Aboriginal Australians before newcomers arrived and brought bad food etc.
Observations that are regarded as very difficult to us would probably be easy for a young person with good native vision.
Seeing Jupiter's moons.
Seeing the crescent of the planet Venus.
Seeing Saturn's oblong shape.

In addition they may have known that a small star moves slowly, namely the planet Uranus.
They may have discovered this thousands of years ago.
This is relatively easy to see in a dark sky. I have seen it often, but it was only discovered by Herschel as a comet and then a new planet.
I think Galileo and others saw it with early telescopes, but didn't notice that it moves. It is recorded on their drawings.

There is one observation that should be possible, but I haven't had a positive sighting yet.
Namely, seeing Neptune without optical aid. It is magnitude 7.8 and should be possible at the zenith, but is currently well south of the celestial equator. So only near the zenith in the southern hemisphere.
It has a peculiar spectrum, which maybe why it has not yet been seen.
But I think that in the dark Australian skies the Aboriginies could have seen it.
I would think that the bright sunshine might have damaged their eyes unless they took very great care during the day. So maybe their eyesight deteriorated rather quickly with age.

 

[Theo98]

Come guys, help me out here.

Ron

Hi Ron,

To answer your original question, "is it me, my eyes"...probably, Yes! :eek!:

Ted

 

[WJC]

Hi Ron,

To answer your original question, "is it me, my eyes"...probably, Yes! :eek!:

Ted

So many of the problems laid at the feet of the opto-mechanical should more rightfully be blamed on the physiological. :cat:

Bill