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Startling Statistics from Nature (1 Viewer)

Troubador

Troubador

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Kowa's Genesis 8x33 can resolve 3 Starling-pairs per foot. I know because during field work for my review, the Starlings lined up on a local roof ridge.
I am sure that they can do much better than this but getting smaller species to line up on roof ridges isn't easy.

In a similar vein, Zeiss SF 8x42s can resolve 3 European Otters (side by side) per yard, on the rare occasions they stop moving, and HT 8x42s can do 3 Red Squirrels per foot, subject to what they are doing with their tails.

Come on pals, someone out there can do better than that. Swallows on a wire? Red-footed Falcons over a termite hill, Prairie Dogs on, well, a prairie?

Lee
 
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Funny you bring this up, but in all seriousness many of my tests for 'sharpness' or whatever you want to call it, are nature based.

For example, I use the 'eye' spots on Duskywing Butterflies to test for separation. These tiny eyespots, each likely less than 2 mm long and .5 mm wide are white on a dark background. Each of the 4 or 5 spots is divided by an ultra-thin black line. At close focus distance, I need to be able split the spots cleanly, as well as see no 'bleed' of white onto the dark background.

Same goes with Dragonflies - using Clubtails, I will try to resolve leg spines. These spines can vary from a few mm to less than .25 mm or so, a really good test. Cerci are another great test as the structures can be so fine.

Somewhat standardized, one of my favourite walks has a pond with many basking Painted Turtles. The same turtles bask in the same places, year-after-year, so viewing distances do not vary. My old Elite's could not separate the fine yellow and black lines on the neck and legs but my newer equipment does.

I also have a view from the front of my house, across a valley where there is a dead elm tree - almost exactly 1 km according to Google earth. I use this as a reference, as my sharpest bins show the small knobs on the thin, upper branches. This tree is a favourite perch for many bird species, especially icterids. I should be able to distinguish Grackles from Red-wings etc. on shape alone from this distance, if the optics are up to it. It's a tough test as it usually involves dark objects against a gray background.

I have many other 'field' tests, all very unscientific, but I find if a binoc. works in these situations then it should prove more than up to the task for regular fieldwork.
 
My Zeiss SF 8x42 can resolve 2 policemen "per" 8 feet (or was that on 8 feet???) :eek!:
 

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james holdsworth said:
Funny you bring this up, but in all seriousness many of my tests for 'sharpness' or whatever you want to call it, are nature based.

For example, I use the 'eye' spots on Duskywing Butterflies to test for separation. These tiny eyespots, each likely less than 2 mm long and .5 mm wide are white on a dark background. Each of the 4 or 5 spots is divided by an ultra-thin black line. At close focus distance, I need to be able split the spots cleanly, as well as see no 'bleed' of white onto the dark background.

Same goes with Dragonflies - using Clubtails, I will try to resolve leg spines. These spines can vary from a few mm to less than .25 mm or so, a really good test. Cerci are another great test as the structures can be so fine.

Somewhat standardized, one of my favourite walks has a pond with many basking Painted Turtles. The same turtles bask in the same places, year-after-year, so viewing distances do not vary. My old Elite's could not separate the fine yellow and black lines on the neck and legs but my newer equipment does.

I also have a view from the front of my house, across a valley where there is a dead elm tree - almost exactly 1 km according to Google earth. I use this as a reference, as my sharpest bins show the small knobs on the thin, upper branches. This tree is a favourite perch for many bird species, especially icterids. I should be able to distinguish Grackles from Red-wings etc. on shape alone from this distance, if the optics are up to it. It's a tough test as it usually involves dark objects against a gray background.

I have many other 'field' tests, all very unscientific, but I find if a binoc. works in these situations then it should prove more than up to the task for regular fieldwork.
Click to expand...

Great examples James.

Your butterfly test sounds a great one as does your turtle-test because you have distance control.

When you repeat these many times a year, and year after year (our test would be the whiskers on Otters and Seals) it becomes a reliable gauge as to how bins are performing with regard to perceived sharpness.

Thanks for posting these.

Lee
 
Some of my first "tests" with any new or borrowed bin is to view the wooded lot across the road from me (35-40 yards) and look for:

1. How much "bark detail" I can resolve on various trees near the edge of the woods, usually compared to another similar classed (or higher or lower classed) binocular. I'm not up on my tree identifications but one or two trees along the near edge of the woods are hardwoods with well defined coarse bark, that makes a good test of a bins ability to resolve as well as deal with mixed illumination - areas of light (outer surface of the bark) and dark (the "valleys" in the bark).

2. I then try to focus on the individual leaves of hardwoods or lower canopy plants (rhododendron for instance). Again this is primarily a resolution test but also I note the way the color is projected through the bin as opposed to the naked eye. I like to do this with trees/plants at ground level or near level to the eye-not high in the trees to be fairest to the optics (as opposed to against the sky-although I guess that would be a telling test also.)

3. I also like to note how far I can see "into" the woods to still resolve detail in bark and leaves; this (to me) gives an idea of a bins ability to perform in low or difficult lighting conditions as the sunlight in already waning by most afternoons or evenings when I might be doing this. This (again, to me) is actually a very relevant test, as I would want to be able to find a bird in deep woods and late in the day, but I don't bird at night so simply testing at night for low light ability would be moot for me. I may bird until dark however (usually on Sundays or days before I go back to work-trying to get every minute of relaxation and joy before going back to the grind!) :t:

All of these are easily done any time of the year. Of course actual BIRDS are nice and more fun, but can be "hit or miss" when I'm out there.
 
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David in NC said:
Some of my first "tests" with any new or borrowed bin is to view the wooded lot across the road from me (35-40 yards) and look for:

1. How much "bark detail" I can resolve on various trees near the edge of the woods, usually compared to another similar classed (or higher or lower classed) binocular. I'm not up on my tree identifications but one or two trees along the near edge of the woods are hardwoods with well defined coarse bark, that makes a good test of a bins ability to resolve as well as deal with mixed illumination - areas of light (outer surface of the bark) and dark (the "valleys" in the bark).

2. I then try to focus on the individual leaves of hardwoods or lower canopy plants (rhododendron for instance). Again this is primarily a resolution test but also I note the way the color is projected through the bin as opposed to the naked eye. I like to do this with trees/plants at ground level or near level to the eye-not high in the trees to be fairest to the optics (as opposed to against the sky-although I guess that would be a telling test also.)

3. I also like to note how far I can see "into" the woods to still resolve detail in bark and leaves; this (to me) gives an idea of a bins ability to perform in low or difficult lighting conditions as the sunlight in already waning by most afternoons or evenings when I might be doing this. This (again, to me) is actually a very relevant test, as I would want to be able to find a bird in deep woods and late in the day, but I don't bird at night so simply testing at night for low light ability would be moot for me. I may bird until dark however (usually on Sundays or days before I go back to work-trying to get every minute of relaxation and joy before going back to the grind!) :t:

All of these are easily done any time of the year. Of course actual BIRDS are nice and more fun, but can be "hit or miss" when I'm out there.
Click to expand...

David thats a first class example of using what is available and becoming so familiar with it that you can spot differences easily.

Lee
 
I thought I'd get someone I first met a couple of years ago to give my binoculars the once over. I know he has visual capabilities we can only dream of, so I thought we'd all benefit from his appraisal. I've got rather like to his clear decision making and curt, often damming, judgements. He's rather inclined to dismiss my own technical analysis, prefering to sieze the moment and make a judgement for himself. Of course it has left me puzzling over how on earth he does it. I was rather impressed by the speed of his evaluation of the little group I got out for his consideration and his ability to almost instantly dismiss well regarded models with a contemptuous "No!". Finally, we found a binocular that met his exacting requirement. "Two big birdies. I like it!" So there we have it. The Opticron Classic 7x36 was the clear cut winner. He quickly moved on to make an equally decisive critique of Postman Pat versus Fireman Sam.

David
 
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typo said:
I thought I'd get someone I first met a couple of years ago to give my binoculars the once over. I know he has visual capabilities we can only dream of, so I thought we'd all benefit from his appraisal. I've got rather like to his clear decision making and curt, often damming, judgements. He's rather inclined to dismiss my own technical analysis, prefering to sieze the moment and make a judgement for himself. Of course it has left me puzzling over how on earth he does it. I was rather impressed by the speed of his evaluation of the little group I got out for his consideration and his ability to almost instantly dismiss well regarded models with a contemptuous "No!". Finally, we found a binocular that met his exacting requirement. "Two big birdies. I like it!" So there we have it. The Opticron Classic 7x36 was the clear cut winner. He quickly moved on to make an equally decisive critique of Postman Pat versus Fireman Sam.

David
Click to expand...

LOL :t:
He probably made the right choice David, your 7x36 is very nice as I recall.

Your pal might have struggled comparing Rag, Tag and Bobtail with Four Feather Falls though.

Lee
 
A Nikon 8X30 EDII can resolve an infinite number of Mourning Doves along a undetermined length of a seed line.
 

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BruceH said:
A Nikon 8X30 EDII can resolve an infinite number of Mourning Doves along a undetermined length of a seed line.
Click to expand...

This is a decent effort Bruce. I give it 9/10 for optimism and 6/10 for accuracy. You cheerfully admit that the length of the seed line was unknown and your claim that there is an infinite number of Mourning Doves doesn't stand scrutiny. I count 81 doves in the pic and even if I am wrong by 10% I think this scuppers your claim for an infinite number. And they aren't lined up side by side to mimic the line-pairs in the USAF test so it is of limited use in the technical evaluation of your Nikon 8x30. Still, it is a gallant first attempt and I am sure you can do better.

Lee
 
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Troubador said:
Come on pals, someone out there can do better than that. Swallows on a wire? Red-footed Falcons over a termite hill, Prairie Dogs on, well, a prairie?

Lee
Click to expand...

For immediate sharpness, clarity and resolution of new-to-me optical instruments, how about my own USAF test...A hand-held 10x42L with IS engaged, I can read 6mm (1\4") courier-new font type from 105m away!! :eek!: :smoke: B :)

Ted
 
Not exactly nature, but I check close focus by looking down at my feet...I'm around 1m 90cm tall, so if I can focus on my feet that's pretty good.

The Genesis 8x33 manage that very well, just to plug them again (honest guv, I have no connection with Kowa, I just like them).
 
Troubador said:
This is a decent effort Bruce. I give it 9/10 for optimism and 6/10 for accuracy. You cheerfully admit that the length of the seed line was unknown and your claim that there is an infinite number of Mourning Doves doesn't stand scrutiny. I count 81 doves in the pic and even if I am wrong by 10% I think this scuppers your claim for an infinite number. And they aren't lined up side by side to mimic the line-pairs in the USAF test so it is of limited use in the technical evaluation of your Nikon 8x30. Still, it is a gallant first attempt and I am sure you can do better.

Lee
Click to expand...

Lee .... You are only seeing just part of the line so do not be so quick in doubting my claim of an infinite number of Mourning Doves. Keep in mind they breed like mice so for every 81 you count, there are many more than that hatching.

Also consider the line could be in a circle which means there is no end to it.

I do know what you were up to in specifying 81 birds. You are having fun with my OCD personality and knew that I would have to go back and count the number in the picture. I got 105 but am not sure, so I will be recounting them several more times today. ;)

There were also a couple of House Sparrows at the beginning of the feeding frenzy but I could only find one in the photo so I assume the other was eaten by the glutinous hoard.

As far as getting them to line up for in-line pairs .... have you ever tried training a Mouring Dove! These are not White Doves.

Actually, I would give myself a 1/10 for accuracy, since the birds are at least Mourning Doves. :king:
 
BruceH said:
Lee .... You are only seeing just part of the line so do not be so quick in doubting my claim of an infinite number of Mourning Doves. Keep in mind they breed like mice so for every 81 you count, there are many more than that hatching.

Also consider the line could be in a circle which means there is no end to it.

I do know what you were up to in specifying 81 birds. You are having fun with my OCD personality and knew that I would have to go back and count the number in the picture. I got 105 but am not sure, so I will be recounting them several more times today. ;)

There were also a couple of House Sparrows at the beginning of the feeding frenzy but I could only find one in the photo so I assume the other was eaten by the glutinous hoard.

As far as getting them to line up for in-line pairs .... have you ever tried training a Mouring Dove! These are not White Doves.

Actually, I would give myself a 1/10 for accuracy, since the birds are at least Mourning Doves. :king:
Click to expand...

OK, I'm convinced but I disapprove of additional facts being thrown in after the original post. But since you definitely got more subjects into the picture than anyone else so far you go to top of the class.:king:

Lee
 
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