Solar Filter Help

[Joe_Dinsdale]

Hi all,

Im looking to start doing some solar observations. After seeing this years total eclipse i knew i wanted to see the sun up close. My only issue is i have no Solar filter for my telescope. I read some guides online to make one for my self using some  Baader Planetarium AstroSolar Sun Filter. So i had a go at making one.

This did not go well, the one i made worked good for 1 observation session, but taking it off my telescope when i was done just made it fall to bits. I wasted a lot of the filter as well making it, so i was unable to attempt to make another. Now im ready for another go but this time i want to do it properly.

So I don't want to make my own one again, i don't like the risk of doing it wrong and blinding my self. I have around £100($153) to spend at the moment on this and i was hoping you all could help. My telescope is a Celestron Nexstar 6SE, i have seen their are 2 types of filter i could buy. The first is like a film filter,

similar to the one i tried to make. The other is a glass filter. Is one better then the other? is their any difference with what they can do?

If anyone could point me in the right direction to one that would fit and work well with my telescope i would really appreciate it. From what i have found my self im struggling to tell if they will fit my telescope.

I also have a safety question. For 90% of the time i will be observing the sun, i will have a camera connected to my telescope and be view the sun on its display while taking photos. But my question is for the 10% if the time i will not have the camera with me. Is it safe to just look any eyepiece? or should i keep it below a certain magnification?

Thanks for any help you can provide.

[Northern Soul man]

Hi Joe and a very warm welcome to the SGL mate.  I've just started doing some Solar observing - I have the Astrozap ready made filter from FLO - its very well made with an Aluminium cell which holds the solar film and has three strong bolts on the side to secure to the front of the scope - I just use my 127mm Mak from Celestron - It works very well.

If you want to go down this route you need to measure the outside diameter from the front of your scope and have a look on FLO's site for one to match - as said I have the Astrozap cell with the Baader film attached - I asked this same question when beginning and was told that the Baader film was much better than the glass counterpart - also cheaper.

Regarding what you can actually see - quite a lot.  The sunspots stand out very well with the umbra and penumbra of the actual spots very clear - you don't really need much magnification - I only use a 40mm (x37.5) and 26mm plossl  (x57) EP's (they are Meade 4000 Super Plossl's) - these work very well - the 40mm shows signs of granulation on the Sun's surface - but this is very subtle and seeing conditions play a major part in what you can actually see - some days are better than others, also, using the 40mm Plossl I can see faculae (brighter areas/linear features) - but these are more prominent towards the edges of the disk and also rely on good seeing conditions - some days you can see them and other days not so well.

Also filters have helped me to pick out the faculae - with the aperture I use I tend to go for the lighter filters, like very light blue Wratten number #82a, light yellow/green Wratten numbers #8 and #11 - these , for me, make the brighter Faculae stand out a little better, I've also used a much darker green filter Wratten number #56 and #58 have been suggested (if you have any colour filters experiment with them first), but I tend to go for the lighter/paler filters as mentioned.

You can never be too careful when it comes to Solar observing ALWAYS ALWAYS ALWAYS check the filter before using it - hold it up to the light and have a good look through it to make sure there are no large holes in it anywhere and not to use it if there are.  I have a filter for my finder scope, but many tend not to use them, so take the finder OFF or COVER it. The box my filter came in is very sturdy and there is a cardboard cover which fits over the filter for protection - so it can be stored/protected when not in use.

Hope that helps a little Joe, you can always phone FLO to check which filter you would need  for your 6SE - I find that the simple Plossl EP's work very well for Solar - so not too expensive - but the next step up for Solar is maybe a Wedge for white light (which the Baader filter allows you to observe) and the next step up from that is a dedicated Ha scope - very expensive, but these show the Prominences which loop off the side of the disk  - but to be honest as an introduction to the Sun, the Baader film is well worth it for the amount that you can actually see.

Paul.

[Joe_Dinsdale]

Hi Joe and a very warm welcome to the SGL mate.  I've just started doing some Solar observing - I have the Astrozap ready made filter from FLO - its very well made with an Aluminium cell which holds the solar film and has three strong bolts on the side to secure to the front of the scope - I just use my 127mm Mak from Celestron - It works very well.

If you want to go down this route you need to measure the outside diameter from the front of your scope and have a look on FLO's site for one to match - as said I have the Astrozap cell with the Baader film attached - I asked this same question when beginning and was told that the Baader film was much better than the glass counterpart - also cheaper.

Regarding what you can actually see - quite a lot.  The sunspots stand out very well with the umbra and penumbra of the actual spots very clear - you don't really need much magnification - I only use a 40mm (x37.5) and 26mm plossl  (x57) EP's (they are Meade 4000 Super Plossl's) - these work very well - the 40mm shows signs of granulation on the Sun's surface - but this is very subtle and seeing conditions play a major part in what you can actually see - some days are better than others, also, using the 40mm Plossl I can see faculae (brighter areas/linear features) - but these are more prominent towards the edges of the disk and also rely on good seeing conditions - some days you can see them and other days not so well.

Also filters have helped me to pick out the faculae - with the aperture I use I tend to go for the lighter filters, like very light blue Wratten number #82a, light yellow/green Wratten numbers #8 and #11 - these , for me, make the brighter Faculae stand out a little better, I've also used a much darker green filter Wratten number #56 and #58 have been suggested (if you have any colour filters experiment with them first), but I tend to go for the lighter/paler filters as mentioned.

You can never be too careful when it comes to Solar observing ALWAYS ALWAYS ALWAYS check the filter before using it - hold it up to the light and have a good look through it to make sure there are no large holes in it anywhere and not to use it if there are.  I have a filter for my finder scope, but many tend not to use them, so take the finder OFF or COVER it. The box my filter came in is very sturdy and there is a cardboard cover which fits over the filter for protection - so it can be stored/protected when not in use.

Hope that helps a little Joe, you can always phone FLO to check which filter you would need  for your 6SE - I find that the simple Plossl EP's work very well for Solar - so not too expensive - but the next step up for Solar is maybe a Wedge for white light (which the Baader filter allows you to observe) and the next step up from that is a dedicated Ha scope - very expensive, but these show the Prominences which loop off the side of the disk  - but to be honest as an introduction to the Sun, the Baader film is well worth it for the amount that you can actually see.

Paul.

Hi Paul,

Thanks for your reply. I have just been looking at the FLO website and have found a Astrozap Baader Solar Filter. I have just measured my telescope and got 182mm. The closest match i can see on their site is 174-184 mm for £44. So im guessing that's the one that will fit.

I will place my order for it tomorrow.

As for my eyepieces i have a handful ranging from a 6mm to 32mm. So i should be best off using the 32mm, when im not using my camera.

[Northern Soul man]

Hi Ya Joe - yes nice 1 mate, should be a very good fit over the 6SE, the thumbscrews that come on the outside of the filter are very good and it looks very nice when on the front of the scope - anything better than I was able to cobble together - all we need now is the clear skies, but with Solar it gives us a chance to use the scope in the day - at a reasonable hour, you can watch the sunspots grow over a few days, but I think the main thing with observing be it day or night is PATIENCE - you can build a nice picture up over the space of a few days, some will be better than others regarding the seeing conditions, trying to avoid the middle part of the day which creates the most turbulence - but the weather may be the biggest problem, as you know, clear sunny, cloudless skies are very few and far between.

Kind Regards.

Paul.

[Floater]

Joe, you're absolutely on the button. I think you'll love observing the sun.

Paul has given good advice. You can't go wrong with the Baader Astrozap.

Sunspot activity is rather quiet (to say the least!) at present but that will change. In fact, that's the beauty of solar observing - it changes. The doubles, the clusters, the galaxies and nebulae show little, if any change. But man, the sun changes.

From your introductory post, you've not been getting the scope out a lot - that will change, too. And play around with all your EPs, why don't you.

Enjoy.

[Joe_Dinsdale]

Hi Ya Joe - yes nice 1 mate, should be a very good fit over the 6SE, the thumbscrews that come on the outside of the filter are very good and it looks very nice when on the front of the scope - anything better than I was able to cobble together - all we need now is the clear skies, but with Solar it gives us a chance to use the scope in the day - at a reasonable hour, you can watch the sunspots grow over a few days, but I think the main thing with observing be it day or night is PATIENCE - you can build a nice picture up over the space of a few days, some will be better than others regarding the seeing conditions, trying to avoid the middle part of the day which creates the most turbulence - but the weather may be the biggest problem, as you know, clear sunny, cloudless skies are very few and far between.

Kind Regards.

Paul.

ye this can only mean me using my telescope more as know i can us it during the day thanks for all your advice.

[Joe_Dinsdale]

Joe, you're absolutely on the button. I think you'll love observing the sun.

Paul has given good advice. You can't go wrong with the Baader Astrozap.

Sunspot activity is rather quiet (to say the least!) at present but that will change. In fact, that's the beauty of solar observing - it changes. The doubles, the clusters, the galaxies and nebulae show little, if any change. But man, the sun changes.

From your introductory post, you've not been getting the scope out a lot - that will change, too. And play around with all your EPs, why don't you.

Enjoy.

Thanks for the reply. I cant wait to see my first sun spots and i will see witch of my eyepiece works best

[Dave In Vermont]

I use the Helio-Pod from this outfit:

http://www.dynapod.com/dyna-hp1.html

And here's the front-door where you can find dealers:

http://www.dynapod.com/

These make centering the Sun in your eyepiece a breeze. It's a one-man operation and the owner is very nice guy. He'll be happy to answer any questions you may have about these goodies. And you won't need to buy a separate filter for your finder-scope - just be sure to keep it capped during your daytime fun.

For filters I use the Baader Solar-Continuum filter. These take some getting used to - they will turn the Sun green. But they do make it easier to make out the surface granulation.

Sunny Skies,

Dave

[Floater]

+1 for the Helio-Pod finder and can confirm that the owner is a 'very nice guy'. I had an email conversation with him when I bought my finders (see below) and he's very helpful.

The reason I bought more than one - three, actually - is that I don't think there are any dealers in the UK and the shipping for one is the same as for two or three. They are relatively inexpensive so it's not too costly ...

Astroboot used to do a perfectly serviceable solar finder for a good price but I've not seen them advertised for a while. Might be worth a hunt round, though.

[Joe_Dinsdale]

I use the Helio-Pod from this outfit:

http://www.dynapod.com/dyna-hp1.html

And here's the front-door where you can find dealers:

http://www.dynapod.com/

These make centering the Sun in your eyepiece a breeze. It's a one-man operation and the owner is very nice guy. He'll be happy to answer any questions you may have about these goodies. And you won't need to buy a separate filter for your finder-scope - just be sure to keep it capped during your daytime fun.

For filters I use the Baader Solar-Continuum filter. These take some getting used to - they will turn the Sun green. But they do make it easier to make out the surface granulation.

Sunny Skies,

Dave

+1 for the Helio-Pod finder and can confirm that the owner is a 'very nice guy'. I had an email conversation with him when I bought my finders (see below) and he's very helpful.

The reason I bought more than one - three, actually - is that I don't think there are any dealers in the UK and the shipping for one is the same as for two or three. They are relatively inexpensive so it's not too costly ...

Astroboot used to do a perfectly serviceable solar finder for a good price but I've not seen them advertised for a while. Might be worth a hunt round, though.

Thanks for letting me know about the Helio-Pod i will take a look at them when i get home from work.

Also I have noticed a lot of people saying to cover the finder scope during observation of the sun. I don't have a cap to cover it, but i sure i can find something that will do the job. Whats the main reason for covering it? will it get damaged if left uncovered?

[Floater]

I think the main reason for capping/covering the finder is to make sure you don't look at the sun through it! It may seem unlikely you would do such a silly thing but while concentrating on something else it would take just a careless moment to damage your eyesight. However, there is also the consideration that heat could build up and/or be projected through the finderscope.

To a large extent, it will depend on your setup. The RACI Finder on my Dob is always capped when viewing in white light; the plugs are always left in the Starbeam when using the larger of my fracs, and on the smaller frac I have a simple Kwik Point red dot finder which I do not cover.

I guess the main message is that you can never be TOO careful when viewing the sun.

Other, more knowledgeable, Sol hunters may be able to add more info.

To answer a question you didn't ask, but which many do ask, the reason for having a solar finder in the first place is that it can be surprisingly difficult to centre even such a large object as the sun in the eyepiece without using a finder. And I, for one, quickly became fed up faffing around with the 'shadow' technique!

[Joe_Dinsdale]

I think the main reason for capping/covering the finder is to make sure you don't look at the sun through it! It may seem unlikely you would do such a silly thing but while concentrating on something else it would take just a careless moment to damage your eyesight. However, there is also the consideration that heat could build up and/or be projected through the finderscope.

To a large extent, it will depend on your setup. The RACI Finder on my Dob is always capped when viewing in white light; the plugs are always left in the Starbeam when using the larger of my fracs, and on the smaller frac I have a simple Kwik Point red dot finder which I do not cover.

I guess the main message is that you can never be TOO careful when viewing the sun.

Other, more knowledgeable, Sol hunters may be able to add more info.

To answer a question you didn't ask, but which many do ask, the reason for having a solar finder in the first place is that it can be surprisingly difficult to centre even such a large object as the sun in the eyepiece without using a finder. And I, for one, quickly became fed up faffing around with the 'shadow' technique!

Thank you for the answers. I will make sure I cover it so I don't accidently look through it. As for the solar finder I like the idea, but before I spend money on one I would like to see how difficult it is with out it.

[Floater]

Quite right, Joe.

Meantime, if you search for 'finder' in the Observing - Solar forum you'll find lots of ideas for DIY projects ... as well as many opinions on solar finders in general and whether or not they are needed.

[Joe_Dinsdale]

Quite right, Joe.

Meantime, if you search for 'finder' in the Observing - Solar forum you'll find lots of ideas for DIY projects ... as well as many opinions on solar finders in general and whether or not they are needed.

Thank you for the advice

[Roy Challen]

I might be wrong, but I think Herschel wedges cannot be used with any kind of reflecting telescope, or Petzval type refracting scope. So don't waste your money if you have one of these types. Unless I'm wrong of course!

[Stu]

I might be wrong, but I think Herschel wedges cannot be used with any kind of reflecting telescope, or Petzval type refracting scope. So don't waste your money if you have one of these types. Unless I'm wrong of course!

You are not wrong Roy, but in this instance the OP is talking about a full aperture filter on the front of his 6SE which is fine.

[RT65CB-SWL]

Just adding my 2p/2c worth here regarding glass solar filters...

1. I use a Thousand Oaks glass solar filter and the solar disk/disc is orange/yellow.

2. Like the solar safety film, glass solar filters also need to be checked at before use for 'pinholes' and scratches.

3. Full aperture glass solar filters are expensive.