could you damage your eyes? Is it the same as looking at it w/o a telescope?
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It is very likely that you would severely damage your eye, and doctors can not repair this damage!
But there is more to this story...
Telescopes are incapable of increasing the surface brightness of any extended object (non-point source) it observes any greater than what is seen by the naked eye. Surface brightness simply means the brightness of a specific area upon the disk or blob you are looking at. In other words, it is unit area brightness. The combination of all these areas will give you the brightness of the object and it is called apparent magnitude.
This means that if the Sun at sunset is so dim that it is easy for the eye to look upon it, then the use of binoculars or telescope will not be dangerous. In fact, it may be safer to use binoculars to look upon a dim setting Sun than to look at it with the naked eye. The reason is that the infrared band of light produced by the Sun is not diminished that much by our atmosphere, so when you look upon the dim Sun you are allowing a lot of infrared light into your eye. Glass, however, stops infrared light, and telescopes and binoculars use glass.
So, ironically, it may be better to look at an easy-to-see setting Sun with bincoulars than without.
I once came very close at loosing my eye when a mylar Solar filter cracked in half within my eyepiece as I approached the lens with my eye. So, never look at the Sun with any telescope or binocular that is not properly filtered if the Sun is in any way bright to the naked eye.
But there is more to this story...
Telescopes are incapable of increasing the surface brightness of any extended object (non-point source) it observes any greater than what is seen by the naked eye. Surface brightness simply means the brightness of a specific area upon the disk or blob you are looking at. In other words, it is unit area brightness. The combination of all these areas will give you the brightness of the object and it is called apparent magnitude.
This means that if the Sun at sunset is so dim that it is easy for the eye to look upon it, then the use of binoculars or telescope will not be dangerous. In fact, it may be safer to use binoculars to look upon a dim setting Sun than to look at it with the naked eye. The reason is that the infrared band of light produced by the Sun is not diminished that much by our atmosphere, so when you look upon the dim Sun you are allowing a lot of infrared light into your eye. Glass, however, stops infrared light, and telescopes and binoculars use glass.
So, ironically, it may be better to look at an easy-to-see setting Sun with bincoulars than without.
I once came very close at loosing my eye when a mylar Solar filter cracked in half within my eyepiece as I approached the lens with my eye. So, never look at the Sun with any telescope or binocular that is not properly filtered if the Sun is in any way bright to the naked eye.
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Yes you can damage your eyes. Temporarily if you're lucky, permanently if you're not. You will feel extreme pain upon putting your eye to the eyepiece of an unfiltered telescope. The likelihood and severity of eye damage are worse than with the naked eye.
An account of someone who did so accidentally is here http://mintaka.sdsu.edu/GF/vision/others… (He had a telescope with a switch to change from a low-power finder view to a higher power view in the main scope, and had mistakenly left the filter off the main scope).
An account of someone who did so accidentally is here http://mintaka.sdsu.edu/GF/vision/others… (He had a telescope with a switch to change from a low-power finder view to a higher power view in the main scope, and had mistakenly left the filter off the main scope).