Solar Filter Check

[Abernus]

Hi all,

I recently posted looking for advice on a new scope. However since then my wife has found out she is pregnant so I am not allowed a new scope yet.

So the one I have (Meade EQ 1- will have to do. As the title suggests I am going to have a go at solar observing. I have seen on FLO that you can buy this: Baader AstroSolar Safety Film ND 5.0. My major concern is damage to my eyes, so I am looking for help before I start.

The main cap on my scope has a small aperture cap on it. Now, from what I understand all I need to do is buy the film cut a piece the size of the small cap and secure it over this, point my telescope at the sun and enjoy. Am I correct or am I on a path to damaging my eyes

[brianb]

Twill do that way but (unless your scope is over 8" aperture) a full aperture filter will probably work better. Instructions are printed on a sheet of paper included with the film. If your Blue Peter "sticky back plastic" skills have lapsed, borrow an 8 year old to help you.

[Merlin66]

The Baader Solar film if used correctly is 100% safe!

You can use it to make a full aperture filter, as Brian said "the instructions are on the pack"

[Abernus]

Thanks for the info. I have just ordered the Baader AstroSolar Safety Film ND 5.0 Looking forward to what I can see once I get this done. I think I will have to get in touch with my cousins oldest child, my Blue Peter are very rusty.

[TheThing]

Don't forget to follow all the advice about sun safety (never look at it directly without the filter in place, cover up the finder scope, never leave your scope pointing at the sun without the filter in place etc, etc)

We all bemoan the H&S rules that ruin this country, but when it comes to viewing the sun, it pay to take extra care!

[Abernus]

My Solar filter has arrived. Time to read, read and read and see if I can get it on my telescope for the weekend. Fingers crossed for a sunny day.

[Abernus]

O.K so I made my solar filter and it was no easy task. I read the instructions several times over and knew then of by heart before I began. It's all done but I can not get the finished product to have a smooth surface.

I have tried it on my telescope and no matter what I do I always have a wavy surface. I only tried it for about 10 mins as I had company today but I could not see anything. I am wondering if a slightly wavy finish on the film should affect my viewing?

Any help anyone can give would be great.

[steve_bham]

This might help you:

SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids

it tellls you the current condition on the sun. No sun spots so if all you saw was a white disc then dont worry, there was nothing else to see at this time

[Abernus]

thanks for the link and the quick responce. I could see a plain white disc (just) but I could not see it clearly. It was clear skies but the sun bounced about on what I asume are the waves on the filter. The best view I got was only half a disc of the sun over one of the waves.

[John]

..... It's all done but I can not get the finished product to have a smooth surface.

I have tried it on my telescope and no matter what I do I always have a wavy surface. I only tried it for about 10 mins as I had company today but I could not see anything. I am wondering if a slightly wavy finish on the film should affect my viewing?

Any help anyone can give would be great.

Don't worry all the filters made from this stuff have a "wavy" finish - even the professional ones:

Solar Filters - AstroZap Baader Solar Filter

It should not effect your viewing.

John

[Merlin66]

I've built two or five solar filters from the Baader solar film.

They NEVER come out perfectly flat, and the images have always been 100%.

Whatever the problem ( probably seeing conditions) it wasn't the wavey solar film.

[red dwalf]

don`t worry about wavy lines, i have a proper Celestron 6" sct solar filter ( £70 plus new ) and it says in the instructions that the surface should be rippled and not flat or tight in any way, this is normal and it won`t change or distort the image and it works great, must say though that there was not much to see at the time i used it !

[brianb]

all the filters made from this stuff have a "wavy" finish

Far better that than stretched tight, when optical distortion can occur!

[Abernus]

Ah, all good news then. Thanks jahmanson for the link, this looks like the finish on my solar filter. At least I know I built it correct.

I didn't like working with the stuff, it's soo thin and flimsy. Also I was worried I might rip it. However from the off cuts I had left I had a play and it's surprisingly strong stuff, although it does pick up fingerprints very easily.

Now just waiting for a sunny day and for some sun spot activity to have another check and hopefully better results.

[Macavity]

I think, if (like me!) you STILL want to make "flat ones" you can achieve approximately that. Just make two annular rings out of "something" (thin aluminium, cardboard etc.) and sandwich a "circle" of film between them. As brainb implies, wrinkles may avoid "crystalline" effects in the film and reflections back and forth. Indeed some films are now marketed as being without (at least) the former pathology...

But frankly, I seem to get the same result from (budget) FILM as with my (expensive) "Thousand Oaks" glass filter. And I rather like the idea of a "less orange" (blue-white?) image with the Baader stuff? You can then fiddle with conventional filters to clean things up.