[FONT=“Trebuchet MS”]Here’s the basic scoop about your eyes and solar events. Your best bet when viewing an eclipse or an event like the Venus Transit is to use a specially filtered telescope under the supervision of professional scientists. Your second best bet is to use #14 welder’s goggles and nothing of lower protection than that. Period. If you want a really lame experience like I had as a kid, try making one of those viewing pinhole things, which is a total waste of time and makes you end up looking up into the sun anyway.
If you cannot resist the urge to look, and let’s face it, most of us can’t…just please take a very quick glance and leave it at that. Wait until a point when you figure the dot will be somewhere you think is aesthetically pleasing to you, and take a very quick peek. Retinal damage is cumulative–it accrues over time. Every time you are forced to [SIZE=“3”][COLOR=“DarkSlateBlue”][/SIZE]drive into the setting sun without your sunglasses, every time you are in any kind of glaring conditions, every time you accidentally look at someone welding or look into photo-therapy lights when visiting your sister’s baby in the NICU, the damage accumulates. It’s not like looking into one event will strike you blind unless you stare into the sun for hours, but you ARE doing damage. So just because, as many of you seem to think, you have no vision change after looking into a solar event, that doesn’t mean damage hasn’t been done. It has.[/FONT][/COLOR]
I’ll mention that my (very basic) telescope came with a Moon filter and a Sun filter*. These were to be put in the eyepiece somehow. I have heard that those Sun filters are A Really Bad Idea, since they can crack from the heat of the Sun being focused onto a point, quickly sending unfiltered sunlight to your eye.
Presumably the specially filtered telescope mentioned above has a filter on the incoming side of the telescope, where there wouldn’t be the risk of overheating, but check or ask first.
Still have them, still in their original plastic wrap.
Smoked glass, exposed film, CDs or DVDs, or Mylar balloons are also NOT safe solar filters.
Several sunglasses stacked up are not a safe solar filter (try saying that five times fast).
Just because it’s not uncomfortable to look at the sun through something, doesn’t mean it’s a safe solar filter. It’s not just visible light that does the damage. Ultraviolet and infrared can damage your eyes, too. You cannot see these wavelengths, so you cannot tell by looking through it if something is blocking all the radiation that can damage your eyes.
Your retina does not have pain receptors, so you won’t feel pain from the damage. The visual effects of eye damage from looking at the Sun aren’t always obvious for a couple of hours after you look at the Sun. Just because you feel fine, doesn’t mean you are OK.
You’re right. Eyepiece solar filters are not something you should ever use. Proper solar filters go over the other end of the telescope.
Eyepiece Moon filters are fine for their intended purpose, but are not to be used to look at the Sun.
One rule of thumb for telling when a telescope is crap is when it lists the magnification on the box. Another is surely that it comes with an eyepiece Sun filter.
To be scrupulously fair, there is such a thing as a safe, high-quality eyepiece solar filter. But they cost thousands of dollars and are for very specialized purposes, so if you don’t know if yours is one of them, it isn’t.
This is not just theoretical. A friend with a modest scope had just such a filter, and when he aimed it at the sun heard a crack and saw a puff of smoke shortly after. Fortunately, he wasn’t looking through it at the time.
More importantly, they are not designed to cut the light level significantly, which is what’s needed here. They (hydrogen alpha filters specifically) are designed to only let through interesting parts of the spectrum. Even with one, you still need a way of reducing the overall light level.
Some solar filters are intended for photographic use only. A filter that is safe to photograph the Sun through is NOT necessarily safe to look at the Sun through.
Clouds that are too thick to see the Sun through are a pretty safe solar filter, though. That’s what it looks like we have here in Pittsburgh.
It was clouded over for the start, but about a half hour after the start, the cloud cover broke, and we got a couple hours of good viewing.
My telescope that Chronos was dissing worked well for this. It’s a standard cheap 2.4 inch refractor (234X!). I used the Barlow lens and no eyepiece, and got an image a little over one inch diameter. (Without the Barlow, the image was smaller, and hard to look at.) I had a piece of cardboard fit onto the telescope to shade the direct sunlight to make it easier to see. Even with my small scope, the image was very bright, and I ended up putting a cross of electrical tape over the front, to dim it.
I got a really nice image, and could see five of the largest sunspots as well as Venus. When there were light clouds, those imaged as well.
I tried using the Sun filter, just held up in front of my eye, and it worked, but as someone said in one of these threads, it was too small to make out Venus.
The clouds blew away in time to look at the sun and see the transit.
Except I didn’t, thinking, as stated above, I am not looking at the sun to try and see a little black dot. (That’s what the internet is for–astrophysical photographs that are safe to view on a monitor!)
I feel sick just imagining looking directly at the sun. My eyesight is already crappy–I can’t imagine looking at the sun directly on purpose. Ugh.
I didn’t say it wouldn’t: Projecting the Sun with enough resolution to see the black dot of Venus isn’t a very demanding task for a telescope. And I’m sure that it was at least as good as the ones Galileo used. That’s still not very good, though.
You were all right, I didn’t see it with naked eye.
Thank you for fighting my ignorance about not looking at the sun. It’s kinda funny cause for decades I’ve thought I was the knowledgeable one and the people worrying were ignorant.
