How do I correctly use eye-piece sun filter?

[crovax]

Well, yesterday I at last got a cloudless sky and decided to test my sun-filter and the new telecope. The telescope is Sky-Watcher 1309EQ2 (900mm/130mm). When I was buyintg it, seller had only sun-filters that are attached to the eye-peice. So I decided to get the best image and somehow put together Barlow Lens, filter and eye-piece (yeah, in that order)

Then I attached this to the telescope and located the sun. Immediately a strange smoke started going from the Barlow Lens and I quickly moved the telescope from the sun and put the barlow lens out of there. The plastic edges of the Lens were fused. I got a file and somehow returned it to the round shape. Then I tested everything and I still can't believe that but all the stuff that took part in the accident was still functioning perfectly.

So now I am sort of afraid of the sun and decided to ask you before making the second attempt. Especially after I found a warning printed on my telescope instruction. It says that I always must use tube filters (not eye-piece filters) because otherwise the interiors of the telescope will be damaged. Well, that makes me a little confused. So can I attach sun filter to the eye-piece and attach this thing to the telescope (without Barlow Lens, I already see that the idea was a bit imperfect )? If no, what's the point in eye-piece filters then?

[Doc]

DON'T use that so called sun filter again. These cheap filters are rubbish and very dangerous, you could be blinded. If you want to get into solar observing you will need proper high quality filters.

[crovax]

Yeah, I'll gladly follow your advice. I guess if something goes wrong, there will be nothing left of my eye in just a moment. I'll be better observing night sky.

[brianb]

DON'T use that so called sun filter again. These cheap filters are rubbish and very dangerous, you could be blinded. If you want to get into solar observing you will need proper high quality filters.

Agree absolutely. Smash the thing with a hammer and drop it in the garbage.

IMO you should never, ever point a modern scope at the Sun unless it has a proper solar filter on the objective (between the scope and the sun). Projection was OK with 3" refractors when they were made of brass and used uncemented eyepieces.... The good news is that Baader solar film works well, is safe when used in accordance with the instructions and is not at all expensive at £15 for a A4 sheet (sufficient for about 4 filters for a 3" scope).

[Doc]

But first hold filter up to light to check if there are none pin pricks.

[crovax]

Thanks much for all the help. I am really happy that my eyes and all the equipment survived in this story.

By the way I also have a similar crappy moon filter. Any advice on it?

[Doc]

Your moon filter will be fine. Even though a full or nearly full moon is bright it's not dangerous.

Your filter will just take the edge out of the glare.

[crovax]

I see, thanks! Can't wait to see the moon next weekend

[RichieP]

Actually I am quite stunned that any dealer would supply such a thing. I haven't seen one on sale for many years - I thought they were illegal to sell these days but that might be just wishful thinking.

Just checking, but this filter, when you hold it up to daylight (but not the sun), does it appear completely black or can you see through it with eveything looking green?

If the latter, then you have a 'Solar Continuum' eyepiece filter. This is meant to be used in conjunction with a full aperture solar filter to pick out more detail.

Regards

Richard

[crovax]

Just checking, but this filter, when you hold it up to daylight (but not the sun), does it appear completely black or can you see through it with eveything looking green?

No, it's totally black and I can't see anything through it. And my moon filter makes everything dark green when looking in it.

Actually I am quite stunned that any dealer would supply such a thing.

Well, apparently that dealer was not very honest when answering on my questions about the quality of the filter.

[Merlin66]

That REALLY p**** me off!!

Those sun eyepiece filters should be BANNED!!!!!!!!!

I'm just thankfull that you and your scope didn't suffer irrepairable damage.

Please, please, let this be a lesson to every other novice.....

The Baader solar film is 100% safe when mounted properly .. highly recommended.

Don't let this "near death" experience put you of observing the Sun; with the correct filters it can be fun!!

[RichieP]

It's not really the quality of the filter, its the whole idea of using an eyepiece solar filter at all. When you use such a thing, the sun's power is magnified and focussed upon the filter by the telescope and it will heat up. It is then in danger of cracking and if that happened whilst somebody was looking through it, they would get a nasty burn on their retina.

Even if that didn't happen, then anything between the main mirror and the filter will heat up also and suffer damage. Your barlow was damaged for this reason but your secondary mirror could also get damaged by the heat.

Only safe way to solar observe is to use a securely fitted full apeture filter as others have said, that way the sunlight is filtered before it enters the scope and so no heat can build up.

regards

Richard

[crovax]

Even if that didn't happen, then anything between the main mirror and the filter will heat up also and suffer damage. Your barlow was damaged for this reason but your secondary mirror could also get damaged by the hea

Yeah, I hope that this thread will oneday help someone to avoid my mistake ))

By the way is there any way to check if my telescope is damaged? After the accident, I checked the eyepiece and the eyepiece+barlow on my test object which is a tower (set by mobile communication company) located in about 600m from me. I was able to get a perfect image of it. Does this mean that everything is fine?

Don't let this "near death" experience put you of observing the Sun; with the correct filters it can be fun!!

Well, may be a little later I'll return to sun observations but for now I'll better be observing it from the internet

[kev 102 42]

name and shame this so called dealer...............kev

[crovax]

Here's the dealer

http://shopping.com.ua/shop/107/167/190/11270.html

however I am sure this will have no effect. In Ukraine we have dozens of similar internet shops and they are not controlled at all. Usually such a dealer is a guy who knows some very cheap place to buy. And when an order is made, he simply goes to that place, buys the ordered thing and transports it to the "office" (which is usually a tiny flat). There the ordered thing is handled to the customer.

[johninderby]

I did see the filter up for sale recently on eBay by a UK based dealer. Thankfully the filter is not listed any more.

John

[The Warthog]

When I was in high school, 45 years ago, the school bought a 60mm refractor, which came supplied with an ep solar filter. We used it a few times without mishap (what did we know!) but opted for using the solar projection screen, a 3" x 3" piece of flat white painted metal on a stick which was easier to look at than the image in the ep. Those were probably Huygenian eps, too.

Which brings me to my real point - if you want to look at the sun but can't afford a filter, you can point the scope at the sun and project the image onto a card, even hand-held if you just want a quick look. Don't give in to the temptation to look in the ep - point the ep downwards, and use the image on the card to manoeuvre your scope once you get close. You can aim the scope by watching the shadow on the ground behind your scope, and then gently moving the scope until you see the ep light up. When I do this, I use the aperture mask, and cover it up every few minutes to keep the ep from getting too hot.

[adamsp123]

Hi Crovax, really a lucky escape, melting your barlow is better than your eye, I have seen the same sunfilter offerded with a scope on UK ebay, I emailed politely, after he had some stroppy emails, explaining the dangers of these sunfilters, which he was completely unaware, he removed it from the sale.

Maybe you could try the same with your guy, worth a try.

BTW how is Kyiv? I was there on a visit a few years ago, a beautiful city, very friendly people.

[crovax]

Which brings me to my real point - if you want to look at the sun but can't afford a filter, you can point the scope at the sun and project the image onto a card, even hand-held if you just want a quick look. Don't give in to the temptation to look in the ep - point the ep downwards, and use the image on the card to manoeuvre your scope once you get close. You can aim the scope by watching the shadow on the ground behind your scope, and then gently moving the scope until you see the ep light up. When I do this, I use the aperture mask, and cover it up every few minutes to keep the ep from getting too hot.

Thanks for all the info but I think next time I'll be playing with the sun I'll have a good tube filter. I really don't want to risk with my eyes and my equipment. The speed at which Barlow melted really impressed me

Hi Crovax, really a lucky escape, melting your barlow is better than your eye, I have seen the same sunfilter offerded with a scope on UK ebay, I emailed politely, after he had some stroppy emails, explaining the dangers of these sunfilters, which he was completely unaware, he removed it from the sale.

Maybe you could try the same with your guy, worth a try.

BTW how is Kyiv? I was there on a visit a few years ago, a beautiful city, very friendly people.

I'll try contacting them but my bet is that it won't affect anything.

Well, it's hard for me to tell if Kyiv is good or bad since I've never been in other cities. Next year I am planning to have a long travel to the US (and to other english-speaking countries if I don't like something about US) so I guess I'll be able to compare it then. However as far as I know a tourist visit and a long-term visit to any city is a large difference. So Kyiv may seem good while you stay in the center of it and while you haven't got into trouble. And if you get into trouble, it's really bad because law system doesn't work here. I guess it's better to think of it as if it doesn't exist at all.

Also ecology problem really s*cks. I like very much to walk around my country house and discover beautifull landscapes. But more and more often I find large heaps of garbage in the places where it used to be a clean and beautiful piece of nature just one year before.

[crovax]

Regarding scope damage. In reality I do have a minor problem so I decided to ask if that's normal. It's about the system that allows you to focus on objects. You know that wheels on the tube that move out or down your eye-piece. The problem is that all this thing is not super-stable and if I move it with hand in different directions, it actually moves. So is taht normal? Also when I was observing Saturn, I didn't manage to get a very sharp image with 10mm+barlow. Is that normal too? Can that be caused by atmosphere (the weather was super random that weekend)? I can only add that I tested all that stuff on a tower located in 600m and I managed to get sharp images of it.

[Merlin66]

Sound like your focusser is a bit weak!

You may want to consider upgrading to a low profile Crayford type which is more stable and has a smooth operation.

Just google on " Crayford focuser for newtonian telescope" - I'm sure you'll find a lot of info.

Skywatcher

[crovax]

Oh, so that's a replacable part! What a relief!

Thanks for the help, I am adding this thing in my to-buy list

By the way is the process of replacing very painful? Does it involve interracting with secondary mirror (will I need to collimate after this)?

[Merlin66]

If you get the right replacement, should only be a matter of removing the holding screws form the existing focuser and bolting on the new one using the same holes!

Will not affect the secondary mirror, but you MAY have to check the collimation ( This is really something you should do everytime you use the scope...)

[crovax]

Thanks, I got it! I guess I even may have time to but it today. Quick question. Is there any actual difference between them:

Baader Planetarium (ìÁÚÅÒÎÙÊ ËÏÌÌÉÍÁÔÏÒ Baader Planetarium | äÏÓÔÁ×ËÁ ìÁÚÅÒÎÙÊ ËÏÌÌÉÍÁÔÏÒ Baader Planetarium | áËÓÅÓÓÕÁÒÙ Ë ÔÅÌÅÓËÏÐÁÍ. ëÉÅ×, ïÄÅÓÓÁ, èÁÒØËÏ×. éÎÔÅÒÎÅÔ-ÍÁÇÁÚÉÎ. äÏÓÔÁ×ËÁ ÐÏ ×ÓÅÊ õËÒÁÉÎÅ.)

Orion LaserMate (Orion LaserMate ËÕÐÉÔØ | Ë ÔÅÌÅÓËÏÐÁÍ | éÎÔÅÒÎÅÔ-ÍÁÇÁÚÉÎ Astroshop.com.ua | ëÉÅ×, õËÒÁÉÎÁ / astroshop.com.ua)

[Merlin66]

I'd honestly suggest to start with a Cheshire collimating eyepiece rather than the laser. It will give you a better "feel" of what's going on with the optics and can quickly be used to check the alignment before you observe.

Collimation - Cheshire Collimating Eyepiece

http://www.cloudynights.com/documents/primer.pdf

Hope this helps.