These have to be Dangerous?

[Earl]

Neutral Density Solar filter. ND1024 on eBay (end time 17-Dec-10 11:05:56 GMT)

[nightfisher]

quite agree!!

[oldfruit]

Absolutely! I think the only way to go is full aperture filtering. Trouble with filters like this (from what i have read) is that the unfiltered sunlight is concentrated onto the filter which would probably heat it and maybe cause it to crack which would be disasterous for any poor soul that happened to be looking through it at the time.

[Dave S]

Not to mention the concentrated heat on the internals of the scope. Back in my teens i tried solar projection through a cheap refractor and melted all the plastic optical mounts inside the tube.

Dave...

[Jamie]

Guys, Can you please take a minute to report this item on Ebay....That's the only way to get it removed....

[Dave Smith]

Guys, Can you please take a minute to report this item on Ebay....That's the only way to get it removed....

Have just done that and also a "Did you realise ....." question to the seller.

Dave

[glowjet]

The add talks of a solar filter, yet the item is described as a Moon filter, warns of not looking at the Sun without a solar filter, confusing to say the least.

[callisto]

I have reported this item

[E621Keith]

Indeed very dangerous. I thought it is illegal to sell this type of solar filter in UK. If it isn't then it should be banned.

[WayBig]

I've also sent a question to the seller pointing out the problem with an eyepiece solar filter

[starstalker]

been ended now by the look of things

[oldfruit]

Looks like this thread may have potentially saved someones eyesight.

[adamsp123]

Still on offer at the mo!!!

ooops, my mistake I missed the "this listing has ended"

[Dave Smith]

I've just received this message from the seller.

"Hi, many thanks for your technical advice about this item. We should certainly take your good point on this.

Thank you again for your advice and Merry Christmas! "

Dave

[Neilius]

Never look at the sun through binoculars or a telescope. The old advice that we've all heard time and time again.

Can someone tell me; even for a split second would the eye be damaged? because I wouldnt look at the sun, even with all the correct filtering equipment, if the truth be told...

[Mr Spock]

Yes, even the briefest glimpse would be enough.

[sbooder]

Yep I have reported too, although it seems a shame that ebay dose not allow for a more descriptive report, it runs out of character allowance

[E621Keith]

Use a magnifying glass and a sheet of paper and see how fast the paper catch fire. Now compare the magnifying glass to your scope's objective several times its size.

If a magnifying glass can raise paper temperature to a few hundred degrees in seconds, it will only take a telescope a fraction of a second to raise your retina temperature by a few degrees to cook it.

[E621Keith]

Just checked it. It's gone

[adamsp123]

I think I heard that it would take about a 30th of a second to boil the back of the eye where of course the light and heat would be focused.

[brianb]

Ummm ... hate to spoil the spoilsports party, but an eyepiece fitting ND3.0 filter is exactly what you need to cut down the excess light - if it's fitted in the exit side of a Herschel (solar) wedge. You'll probably want to use a colar continuun filter or something similar as well.

With the solar wedge, 90% of the heat & light doesn't reach the filter.

Solar wedge + ND3.0 is definitely safe with apertures up to at least 6 inches ...

... of course the text of the eBay listing is "dangerous" but the item itself isn't - when used properly ...

[Earl]

I had to google a Solar Wedge as it was a new one to me

Solar Observing Filters

Interesting one day maybe in another life LOL id like to find the time to do some Solar observing with a nice PST.

The problem with the filter been sold on ebay is I can see someone using it on their 8ich newt 32mm eyepiece and a disaster occurring.

I don't think it is realistically an item that should be sold on ebay to many numptys buy on ebay.

[spaceboy]

I use Baader film for solar observing. I was really reluctant at first due to obvious concerns but I couldn't help but think we spend all our time looking at stars millions of light years away as bright dots and we have one right on our door step. The film works great but it's no H alpha filter so you only see sun spots and some grain to the surface. I always check it up to the sun before viewing through the scope. I would recommend the film, as long as you use common sense while using you get to enjoy our closest star.

[E621Keith]

Baader film and full aperture glass filter is the way to go for white light. Wedges only work with refractors, the sun is hot enough to melt the secondary on reflectors and cats.