Which magnificence is best for the kids?2X,8X,or 10X? (1 Viewer)

I have ordered a pair of binoculars(Hawkeye 8X 21 kids binoculars)for my little brother,as he just started to get interested in plants and birds.We set up a bird feeding spot in our garden,so he need something to watch those visiting birds.
He was very excited after using the binoculars for a walk because he could clearly see the nature.
The Hawkeye binoculars are well made and study.And the clarity is great,even myself want a pair of them.
Here comes the problem,someone on the internet said using binoculars is not good for kid's insight,is it right?Which magnificence is best for the kids?2X,8X,or 10X?
Thank you.

I had binoculars from the age of 4. I still, near 50, have exceptional eyesight. No glasses, no problems. Common sense use and other activities that kept me outdoors and busy! No life staring at screens and iPads is far, far more important than a little binocular use.

On usage wise, binoculars are great when the user gets more experienced with them. Repetition, muscle memory, all come into play, and, a lower magnification with a WIDER field of view can offer a far more relaxed and less stressful introduction. 6x, 7x, 8x, all in little steps u till his hand and eye coordination have reached their peak. Enjoy the fun times out and about with the wild life!

Hi Becky and a warm welcome from me too.

I'm sure you will enjoy it here and I hope to hear about all the birds you see when out and about. I've moved your post to the Binocular Forum and subscribed you to the thread, so you can find it easily.

Hi Becky, welcome to Bird Forum !

I have never heard of binocular viewing being bad for children. That said extreme care us be taken not to look toward the sun, and even bright reflections off water, or shiny metal etc may be unpleasant /harmful. As always, all things in moderation - I certainly think that looking at varying distances and focusing, as a child grows would be beneficial. More expensive binoculars will be built to an international standard which protects against UV light damage. Make sure the binoculars used meet this standard.

Apart from those very serious cautions, the main considerations are age/ size/ strength of the child. There are a number of suitable models at various price points, but excellent optics can be had for even ~$100. One of the main considerations for enjoyment and an acceptable view is how well the binocular fits the child's hands, and eyes. Not all binoculars are created equal, and it's very much an individual match up between the person and the fit of the binocular. Sometimes a heavier binocular is able to be held steadier and for longer because it simply 'fits' the person (little) better.

One key consideration is to make sure that the Interpupillary distance of the binocular suits the child (this is the distance between the center of the two pupils - measure it with a rule). The other thing to get right is the Eye Relief (the distance the eye surface is from the binocular eyepiece lens surface - this is done by twisting, or folding the eye cups out to the correct distance). If the person does not wear spectacles then this generally offers better choice at lower price points.

As far as magnification goes, there is not much benefit in practice to be had beyond 8.5x magnification due to slight hand shakes blurring the image. Suitable magnification are 6.5x, 7x, 8x, or 8.5x. The other part of the equation is the objective diameter. Bigger ones let in more light, but are heavier. Suitable sizes are 21mm - 32mm.

The weight of the bins might be 2 times or more than the one you mentioned - perhaps this will be OK? It is best to try in person (even little before you buy to check the bin fits, is easy to hold steady, can be carried and used for sufficiently long periods, and has a wide clear, bright, sharp view. A Field of View (Fov) of ~400ft or over will be good.

Excellent (glass) binoculars can be had for $100-$200, or up to ~$400. Waterproof ones should last until adulthood.

I don't know the binoculars you have purchased. Some sizes to look at may be ~6.5x30, 8x26, 8x30, 8x32, 8.5x32 .....
Don't be put off by the 'old fashioned' looking ones (porro prisms) as these can often offer better bang for the buck performance.

An interesting one to look at is the 8.5x21 Papillo, which focuses about 3 times closer than normal, and can be lots of fun for kids looking at insects on flowers etc too.

Check out the big online retailers to get an idea of the models available. Maybe there is some sort of store nearby you to try in person. :cat:
https://www.eagleoptics.com/collections/binoculars/20-ounces-and-lower

Enjoy,
Chosun :gh:

Hi Becky,

first of all, welcome to birdforum!

I don't think there is any evidence that the use of optical instruments damages your eyesight.

The only exception is that binoculars or other optical instruments MUST NEVER BE POINTED AT THE SUN!

Please make sure that your little brother understands well that pointing his binoculars at the sun will destroy his eyes in a fraction of a second - so please let him use the binoculars under supervision only until you are confident that this message registered.

Regarding what magnification is best, I would have chosen a 6 or 7x for starters as they are easier to hold steady - but if he likes the 8x pair, that's fine too - after all 8x is the most commonly used magnification for birding.

Joachim

Hi Joachim,
Thank you for your advice.
You are so kind,I will show my brother your response.
Becky,

I would think the 6.5x21 Papillio might be more suitable.

Apparently kids love the Bushnell Xtrawide 4x30 or older 4x21, which might be the same.
Actually they magnify 3.5x and have an 18.5 degree field of view. I have the 4x21.
I don't know if still available.
They don't focus so may not suit children who wear glasses.

jring said:

...The only exception is that binoculars or other optical instruments MUST NEVER BE POINTED AT THE SUN!

Click to expand...

I agree that it isn't a good idea to look at sun (except what is visible during totality phase of a complete eclipse) with the eyes or with binoculars, but generally, doing so is so painful, people don't do it. That's why we don't have to teach babies and little kids not to stare at the sun.

jring said:

Please make sure that your little brother understands well that pointing his binoculars at the sun will destroy his eyes in a fraction of a second - so please let him use the binoculars under supervision only until you are confident that this message registered.

Click to expand...

Looking at the sun through bins is little worse that through one's eyes, which generally people don't do anyway, so I don't think this is something to be concerned about. Right now, in the USA, with the eclipse coming on 21 August, I am seeing a lot of misinformation and paranoia about the dangers of sun viewing. The misdirection bothers me because I think some people on the path of totality will be afraid to look at the sun and will miss their chance to see the sun's corona, solar prominences, etc which are the whole reason that seeing a complete solar eclipse is such an exciting prospect to astronomy buffs.

--AP

Looking at the Sun through a binocular is dangerous.

There are no pain receptors in the eye.

We have reflex actions to prevent us looking at the Sun.

Overcoming our reflex actions using optical aid will cause damage.

With unaided eyes, eye damage occurs from about 1 second to 11 second exposure with a full bright Sun.
Medication such as antibiotics increase risk.
Alcohol or drugs increase risk.
Those having had eye surgery need to contact their surgeon for advice.

The blink reaction, averting our gaze are not really fast enough with binoculars.
The pupil contraction is not very helpful.

Wearing sunglasses increases pupil size and allows more infra red radiation in.

Don't mess with the Sun.

Take advice from competent astro authorities, not from media, newspapers etc.

Hi Alexis,

first of all, we're talking about kids here, little ones probably in case of the brother, so mentioning a once in a lifetime exception is not a good idea to teach an important rule.

Secondly, no - a 42mm binocular has roughly 500 times the area of your brightness adapted pupil of 2mm and thus 500 times the energy gets concentrated in your eye. And no, this time your small pupil size will not save you, the whole eye gets burned.

For a more thorough treatment see

https://eclipse.gsfc.nasa.gov/SEhelp/safety2.html

Joachim

If one stares at the Sun with unaided eyes one burns a track 0.5 deg wide on the retina.
With an 8x binocular the track is 4 deg wide.
The central vision used for reading etc is about 2 deg across.

Sir Roger Moore was advised as a young actor to stare at the Sun to stop blinking.
He wore heavy glasses the rest of his life.
Other actors followed the same crackpot advice.

There was a charlatan eye 'specialist' advising similar for the general public.

U.S. soldiers not wanting to fight in Vietnam burnt out their central vision in the shooting eye to get invalided out.
Doctors could easily spot this as the other eye was fine.
The soldiers went home and thought it worth while.

The Royal Astronomical Society had good advice on eclipse safe viewing. I don't know if the site is still current.

Projection with cheap 10x25 binoculars onto white card or paper is the safest option.
Never stare at the Sun.
Definitely don't look at the Sun with optical aid.

Binastro said:

...There are no pain receptors in the eye.
We have reflex actions to prevent us looking at the Sun...

Click to expand...

Most people describe looking into light that is too bright as "painful" or that it "hurts their eyes" even though they may have no pain receptors.

Binastro said:

...With unaided eyes, eye damage occurs from about 1 second to 11 second exposure with a full bright Sun...

Click to expand...

1 second, seriously? A full second is actually a long time, but still, it doesn't fit with anything I've ever read or experienced.

jring said:

...a 42mm binocular has roughly 500 times the area of your brightness adapted pupil of 2mm and thus 500 times the energy gets concentrated in your eye...

Click to expand...

I agree that the binocular collects more light, but when the pupil is 2 mm it excludes most of the exit pupil and thus that light, and the remaining light is spread over a larger area such that energy/area should be the same as without magnification.

jring said:

For a more thorough treatment see https://eclipse.gsfc.nasa.gov/SEhelp/safety2.html...

Click to expand...

I've read that article before and it seems like a good, conservative, prudent advice. The last couple paragraphs are where I am coming from. I've been to a number of public education events about the upcoming eclipse and I am dismayed that all have intoned that it is "never safe to look at the sun without proper eye protection" and none have discussed looking at the sun directly during totality.

--AP

Alexis Powell said:

I agree that the binocular collects more light, but when the pupil is 2 mm it excludes most of the exit pupil and thus that light, and the remaining light is spread over a larger area such that energy/area should be the same as without magnification.

Click to expand...

Even if we assume that your light adapted pupil of 2mm will limit the amount of energy doing damage, the resulting 8x16 binocular will concentrate 64 times more energy per time unit into that area...

And please see the following article and video as to what happens and why your pupil size will not help - admittedly this is an 80mm telescope with 1500 times more energy per time unit into your eye - or rather a pig's one here and the observation time is that of a very dedicated observer with 20s, but you will certainly agree that permanent damage to the cornea and retina will occur quite some time before things start smoking...

http://www.iflscience.com/space/why-you-don-t-look-sun-through-telescope/

Kids, this is a pretty graphic demonstration, but certainly not worse than dissecting piglets in science class in california like we did during my high school exchange in the 80s... do they still do this nowadays?

Alexis Powell said:

I've read that article before and it seems like a good, conservative, prudent advice. The last couple paragraphs are where I am coming from. I've been to a number of public education events about the upcoming eclipse and I am dismayed that all have intoned that it is "never safe to look at the sun without proper eye protection" and none have discussed looking at the sun directly during totality.

Click to expand...

Well, technically you are not looking at the sun but on the moon during the totality of a solar eclipse... what remains to be seen around it is indeed safe, but you have to make sure to stop observing well before the end of the totality...

Joachim

Of course I am not suggesting anyone look at the unfiltered sun through telescope or binoculars, and I'm not wanting to argue for the sake of arguing, but I still cannot understand why catching a glimpse of the sun through binoculars would be dangerous. I do understand that the magnified sun, even if no brighter per unit area than unmagnified, represents more total energy directed to the retina (albeit over a larger area), which leads to faster heating (since heating occurs over a large area). But it still seems like it would take several seconds for anything potentially bad to happen. Using a magnifying glass or a concave mirror to "focus" the sun to a point leads to tremendous heating (I often did that as a kid to burn leaves), but that isn't the same as what happens through binoculars. I don't find the exit pupil of a binocular trained on the sun to be especially hot on my hand. I just can't understand the basis for the claim that catching the sun through one's bins very briefly (e.g. accidentally, while following a bird flying overhead) could lead to instant partial or complete blindness. That just doesn't ring true to me in practice, or in thinking about it.

--AP

Alexis.

Maybe get a copy of Hazards of Light, Pergammon, before advising on this subject.

Looking directly at the Sun at a fair elevation in a clear sky with a high transmission binocular, damage will usually begin in 1/50th to 1/5th of a second.

People vary a lot in their tolerance to sunlight.
1 second to 11 seconds, with unaided eyes exposure, is the result of analysis of eclipse blindness as discussed by eye doctors following patients presenting to hospital after eclipses.
Patients lying on a beach with the Sun almost overhead are at risk with 1 second direct exposure to the Sun staring with central vision.

When walking our eyebrows and forehead provide protection.

Humans are probably the only creatures stupid enough to deliberately stare at the Sun.
We may think we are immortal or listen to poor advice but that will not help repair damaged eyes.

In the early 1900s Europe had many cases of eclipse blindness, but over the years education has been better.
With the enormous number of deaths and injuries during WW1, eclipse eye damage was just a minor inconvenience.
The work environment was also dangerous, and people expected disability and fairly early death.
We live longer now and need our eyes for longer.

Based on previous eclipses I would anticipate several hundred cases of permanent eye damage in the U.S. from the August eclipse.
But with the internet I cannot even make an estimate, as the media and people's life style has changed.

The reason why accidental exposure while scanning with a binocular often results in no damage is that the track of the Sun on the retina is moving and doesn't have enough time to cause damage.
If you actually stare at a full Sun in a clear transparent sky with a good binocular you will have eye damage. If you are lucky this might start at a 1 second exposure.
But no exposure is safe if staring at a fixed Sun with central vision if using binoculars.

Conjecture is not good enough here.
There are numerous references in Opthalmic Journals to eclipse blindness.
Eye surgeons don't usually bother to do much about repairing the damage, because up till now there is little that can be done.
Maybe in the future we will be able to repair retinal damage.

I personally know of astronomers with lifelong eye damage.
But many people never reveal they have eye damage from the Sun as they are ashamed of what they consider was stupidity. Only after long friendship do they reveal that they don't see well because of Sun eye damage.

Another reason for binocular eye damage is that there is nowhere for the heat to disperse over the larger area, compared to the smaller area with unaided eyes exposure.

Binastro said:

...Looking directly at the Sun at a fair elevation in a clear sky with a high transmission binocular, damage will usually begin in 1/50th to 1/5th of a second...

Click to expand...

My frustration is that there are plenty of admonitions and no easily accessed explanations and descriptions.

The medical articles that I've read about eye damage describe viewing times of tens of seconds to tens of minutes, not fractions of a second.

For something so obvious, it sure is hard to find and access this information.

--AP

Alexis.
This a medical subject, so easy access is not there.

A good University library may have a whole run of the American Journal of Opthalmology.
Possibly also somewhere like Moorfields eye hospital in England.
But you may need some kind of membership or introduction before you can read them.

There is probably a central U.S. library that has millions of books etc.

I spent weeks going through these Journals in the RAS library.
As well as years researching this subject.
Good articles appeared in the past in Sky and Telescope.

The reports of young girls idly staring at the Sun on a beach destroying their eyes make sad reading.
They are now registered blind.

One has to consider that safe filters reduce the Sun's radiation over all wavelengths by 100,000 times.

It is pretty standard that a bright full Moon at about magnitude minus 12.6 is considered the brightest continuous source one should look at.
The Sun is about magnitude minus 26.7, about 450,000 times brighter.

New very recent research indicates that a typical Full Moon is in fact 1 to 2 million times fainter than the Sun, as the magnitude minus 12.6 only applies in the tropics with the Moon overhead at exactly Full Moon. a day earlier or later the Moon is much less bright. An exact Full Moon overhead is rare.

The key points are exposure times and brightness.

I use welders glass 14, large size, which are difficult to get in the U.K.
I think they have a long life.

The eclipse glasses are often of organic material that deteriorates with time and with solar radiation. Normally they are considered safe for 5 years, but we have met fake filters and spent years getting them stopped.
I sometimes wonder why we bother.

I am also not too happy with the Chinese made solar binoculars.
I have little faith in the Chinese approach to safety on many fronts.

If anyone doubts the dangers of solar observing with optics.
My friend who unfortunately died young recently made a filter from 4 sunglasses, I think 8 lenses.
He fastened these in front of a fairly low powered 25mm aperture telescope.
He looked at the Sun and instantly and permanently blinded himself in one eye.
He had some side vision, but the remnants of the damage were always in his eye.

He was eleven.

He lied to his teacher during routine eye tests.
He only told me this many years later.

He became a great Lunar observer and artist and wrote many books.
He used his undamaged eye.

With binoculars one uses two eyes.

Binastro said:

Alexis.
This a medical subject, so easy access is not there.
A good University library may have...

Click to expand...

I am a university professor and have access to just about anything that I want in journals. By not easy to access, I mean that I don't find the information using the methods that I use successfully to research many other far more obscure topics as I do routinely in my profession. If you could provide some citations for me to look up, I would appreciate it.

The web article that jring linked to, and to which we all have access, is typical of what I've seen in the journal articles I've seen so far, and is consistent with what my own eye doctor said when I asked. They seem unalarmed about the potential for instant damage.

--AP

I did most of the research in the 1980s

Americam Journal of Opthalmology articles from were pre 1985 about.
I went through many years.
I am a FRAS.

The Hazards of Light book by Pergammon press is good.
I bought it new. It was expensive.

Sky and Telescope has had articles over many years.

Much of it may not be on the internet.

1 second to 11 seconds was one study for the beginning of permanent damage.
There is emphasis on the variability amongst patients to the tolerance to sunlight.
Alcohol is a great cause of problems as our natural defences are overcome.
The main ones are blink response, averting vision and pupil size change.
The fastest I recall was about 1/40th second.

The use of prescription medication is also a big factor.

There is a great difference between deliberately staring at the sun and accidentally catching it maybe not with central vision.
Staring concentrates the radiation into the macula.

Another study quotes up to 20 seconds before permanent damage.

It warns that eye surgery patients should avoid looking at the sun.

Exposure to a bright sun of minutes with unaided eyes would in my opinion result in permanent irreversible eye damage.

In some cases after follow up, maybe 3 or 6 months there was some improvement, sometimes not.

The intensity of the Sun varies a lot with air clarity, transparency, sun elevation, air water content and particularly height above sea level. Also heavily polluted towns may reduce intensity. I think a factor of 10x can be reasonable here.
UV radiation is generally high with sun elevations above 45 degrees.
The zenithal Sun is very potent.

In the information I had near blue was considered most harmful, but I see later articles saying slightly differently.

A major U.K. physics laboratory carried out studies of a plastic solar filter. It transmitted up to 27% in the infra red.
Users did say they felt their eyes were getting warm. I bought one to carry out tests. It took a leading barrister and years to stop this individual selling them.
He then tried to sell it under an alias.
I don't know how warmth was felt as the eye itself doesn't have pain receptors, but surrounding tissue does.