A guide to viewing our Sun safely

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posted on Oct, 26 2011 @ 07:42 PM
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WARNING:
Never, ever look at the Sun directly through any optical instrument - instant blindness could be the result.
Even looking at the Sun with the naked eye can be harmful.

DO NOT look at the Sun with magnifying glasses, cameras, binoculars or telescopes, any optical instrument in fact, without the use of a properly designed, approved and tested filter or specialised instrument.

DO NOT use photographic film, smoked or tinted glass, plastic or metal film.

Use only materials and instruments designed for the specific purpose for viewing the Sun.

If in doubt, seek expert advice first!




Viewing our closest star can be a very enjoyable experience for all ages and despite the warning above it can also be very easy to do so.
Plus I thought given that with the approaching Solar maximum, increase in Solar activity and increase in interest about our Sun especially here on ATS the time is right to do a bit of a write up and guide on how to safely view the Sun and the different types of ways people can do this and what they can realistically expect to see using different methods without getting too technical. I am aware that I will probably miss certain things out but that doesn't stop others from adding to the thread. This isn't the difinitive Solar viewing guide, just an introduction of sorts.

I also think it is worth people knowing what they will require to safely view the Sun. Time and time again I see people suggest to use something like welding glass or worse as a safe alternative, IT IS NOT!

There are a number of ways one can enjoy seeing the Sun safely and the features that it offers ranging from some inexpensive home made materials no telescope required to the thousands of dollars state of the art equipment, there is a price range for everyone.
The 3 most popular ways of viewing the sun are Solar Projection, White light and with a dedicated Hydrogen Alpha(Ha) solar scope. Between the three methods they will allow you to see features such as sunspots, surface granulation, promininces, filaments and solar flares. But not each method will allow you to see such all the details described.

I also think it is a good idea for people to understand the difference between what you see with your own eyes visually and what you see in the stunning photographs that amatures can produce because there is a difference.

Solar Projection

Firstly I will cover the Solar Projection method, which can be the easiest and cheapest way to view the Sun and a great way to get children involved, it's that simple. Plus it can be argued that this is the safest method of viewing the sun as you are not actually looking directly at it but the image it projects onto a piece of card or paper. This method is popular with those who like to track sunspots and sketch them or just those who enjoy looking at the Sun in a new way.

What will I be able to see?

The disc of the Sun, sunspots, solar eclipses[/url] and solar/planetary transits.

By far the simplest and cheapest method is to use a Pinhole Projector, all you need are two pices of card, and on one piece of card you make a small hole in the center, you then hold that card above the second one and position it so the Sun shines through the hole onto the second card.
See diagram.


You can get creative too, maybe you would like to create a box instead of fiddling with two bits of card. You could try different size holes or more of them.


However you may find that this produces only a small image and would like a bigger image to look at. Well using the same principle this method can be adapted for use with binoculars and telescopes and is a popular method used by amatures. Basically you just replace the piece of card with the hole in it with a pair of binoculars or a telescope and hold the second piece behind the eyepiece.
It is very important that you do not look through the eyepiece at this point or when setting it up, the Suns rays magnified are even more dangerous. Also you must cover up any finderscopes of the side of the binoculars you are not using, we don't need any spot fires behind you whilst observing.


There is also a neat little kit you can buy that generally you build yourself which contains a couple of small lenses and mirrors and makes for a very handy and portable solar viewer. I still use mine to this day.
Solar projection kit
What is in the link is just an example, there are many other makes to choose from.

Here are a couple of links and a pic to give you a rough Idea of you you may see.
www.eclipse-chasers.com...
spaceweather.com...
solar-center.stanford.edu...


White light filters

Now solar projection is a great introduction to solar viewing and a quick and easy work horse for sunspot monitoring but it has it's limitations to what you can see, so the next logical step is to use specialised solar filters for viewing in "White light" which will enable you to see more detail on the Sun's surface beyond just sunspots. This will require a certified and tested solar filter which ranges from coated glass, mylar and the DIY favourite solar film.
Again this method is not purely restricted to having to have a telescope although it does make a big difference in the size and detail that you will see, however there are certified eye glasses and binoculars that are available that use filters to enable safe and more accessible viewing.

What will I be able to see?

The disc of the Sun, sunspots(umbra and prenumbra), solar ecipses, planetary/satellite transits, faculae.

Solar eye glasses

These are a neat little disposable gimmicky product primarily designed to allow people a safe way to view solar eclipses. Depending on their make some are sold just for eclipses and others use the same type of tested solar filter used in telescopes, they are a great way to get people involved without an expensive set up.
One thing you should remember though is the actual size the Sun appears in our sky is the same size as the Moon appears so what you will see is fairly small hence why they are generally used for special events such as eclipses and planetary transits.

Another thing to take note of with these glasses is the fact that the filters are easily scratched and even dust can cause pinholes which can let harmful light in, unless you plan on being extremely careful with your storage of them they should be considered as a disposable type of thing, don't leave them around to gather dust for a year and then use them again. Better safe than sorry really.
Still these are real cheap, only a few dollars a pair so you get value for money.

Here are a couple of examples......
www.eclipseshades.com...
www.astroshop.eu...
Conclusion
A cheap and disposable novelty item that is best used for special occasions, always pay attention to the instructions given by the manufacturer.




posted on Oct, 26 2011 @ 07:43 PM
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Solar binoculars




Now these things are pretty cool, I've had the pleasure to look through a pair once and really enjoyed it, I don't know why I don't own a pair to be honest. They offer a magnified view in white light with the ease of using binoculars. If you have ever used a pair of bino's on the Moon then you will get an idea of what you will see viewing the Sun. Plus these are a relatively cheap way of doing it.

There are a few different options here too, you can get the pre-made specially designed Solar binoculars, you can purchase filters that will fit on your binoculars or you can use the DIY route and make some filter caps or a box for yourself.

How to make a Solar filter for your binoculars.
This is just one method, a quick search will reveal different ways that you can make your own filters, you can really make it any way you want to as long as it is secure and safe. The advantage of this method is the cost, it costs no more than buying the correct solar film and a few odds and ends like pieces of card, glue, tape etc..
Please follow manufacturers guidelines though as they are the guys who truly know what they are talking about.
Of course if in doubt you can use the commercially made and tested variety.

www.scopesnskies.com...
www.scsastro.co.uk...
Conclusion
A fun and simple to use method of observing the sun, a great entry point to solar viewing and can be enjoyed by the all ages.

Telescopes





Alright, so the methods mentioned above are a great starting point to viewing in White light but to really get the most detail out of the Sun's surface one really needs a telescope. It doesn't need to be a specialised scope, doesn't need to be expensive or top of the range and it doesn't need to have a large aperture. All that you need is to be able to fit a filter on the front of your scope. As mentioned there are a number of different brands and types of filters you can use, whether it be coated glass, mylar or solar film but that comes down to what you are most comfortable with using.

You can purchase ready-made and ready to go filters like those in the picture above and link below to fit which ever size scope you own, if your size isn't listed some places will custom build one for no extra cost and that cost is quite affordable to start with. You should be able to find solar filters for well under $100.
www.firstlightoptics.com...

Like with the binoculars, even more so really, DIY solar filters are popular amongst amature astronomers and thankfully, and kind of revolutionary the invention of products like Baader Solar Foil have made this an easy an less expensive option while managing to keep the product at the highest possible quality. Be sure to check the specifications first as some films are designed for photography only and not considered safe for visual observing.

To make a filter again it is a fairly easy process with not many tools needed as can be seen in the tutorial below. Again there are more than one way you can make these filters just be sure to have safety in mind at all times.

How to make a Solar filter for your telescope

Here is an example of the sort of image you can expect to see, right now there is far more sunspot activity on the Sun and is increasing as we approach the Solar maximum so now is as good a time as any to start observing the Sun.


Imaging in white light

One of added bonus' to viewing with a telescope is it can open up the world of Solar photography which is unique in the world of astrophotography in that the Sun is constantly changing, you will never get the same picture two days in a row, it can change in just a matter of hours or less. No other object in the day or night sky offers as much variation, the ever changing Sun is truly a captivating subject even in white light.

Imaging does not have to be expensive although it can be and often is thought to be so, and one doesn't have to spend hours processing images although you can and if you do you will see quite a difference. It can be as simple as finding the right settings on your point and shoot(P&S) camera and holding it up to your eyepiece. But with refinement and better equipment come better results

To get started you need a camera obviously, the three most common and recommended types are DSLR's, webcams and CCD imaging cameras. A DSLR camera is easy to use and can produce good images without much fuss, just take the photo and upload it with little to no time processing it afterwards.

This was one of the first pictures I took using a Canon 20D and a home- made filter, I added the yellow tint to it though the actual image is more black and white. I don't know why we have adopted the Sun being yellow as its real colour is white.


But as you can see that picture is a bit lacking to what can be seen in, well in better and clearer pictures.
To get the absolute most out of the Sun a webcam or CCD camera are really the top performers. The advantage they give is that they capture many frames at a time, hundreds of single frames in a short time span and this is important because when you stack those frames on top of each other it vastly improves the detail that can be seen.



As you can see the difference is substantial. Of course there is nothing to stop you getting similar quality by taking hundreds of photos with a regular digital camera but it is time consuming, memory consuming and a nightmare to process plus you have to be careful as the rotation of the Sun can cause variances. This is where the webcams and CCD's come in handy as they capture 1000's of frames in a matter of minutes.
I'm going to speak of mainly the webcams here as they are really all that are required and are low cost in comparison.

Models like the Toucam, Phillips SPC880's and even LifeCams can all be used with great success and need only minor modifications in software and adaptors to attach it to your eyepiece holder. The only downside is you need to run it off of a laptop or ipad or have a really long usb cable to your PC.
An example of a complete astro package webcam.
The basic process of using it is fairly straight forward too, once you get the exposure and levels correct for the webcam just record a couple of minutes of footage and save the .avi file. Then using a free stacking software program like avistack or deepskystacker you just load the .avi file and let the software do it thing. With a bit of practice you can get great solar images like the one's above.
Conclusion
This is a brilliant and safe way and probably the most common with astronomers to observe the sun and sunspots. It’s not really expensive and frankly if you own a telescope you should get yourself a solar filter so you can enjoy your hobby in the daytime as well.



posted on Oct, 26 2011 @ 07:43 PM
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Hydrogen Alpha(Ha)



Pics from here.

So now we come to the most dynamic and visually exciting area in which you can observe the Sun, by using Hydrogen Alpha(Ha) solar filters. These are the cool filters that allow you to see things like flares, filaments and other surface features and often the changes are quite rapid, an active region can change in a very short amount of time. It is certainly engrossing to watch.
Now using Ha filters have until relatively recently has been something for the professional or those with enough money to buy these scopes, for the most part they are still very expensive items fetching in some cases multiple thousands of dollars and these expensive scopes are extremely good but out of reach to many.

However like I said until recently, now there are a couple of entry level models that have appeared on the market thanks to a couple of innovative manufacturers and for the price of a modest regular astronomical telescope you can now see the Sun in glorious Ha.

What will I be able to see?
Prominences, Filaments, Flares, fibrils, plage, and more.

With the emergence of these scopes like the Coronado PST and the Lunt LS35T viewing the Sun in Ha has been opened up to the everyday amature astronomer and enthusiast for under $500. If there are other models that people know of please do share which ones they are as I haven't come across them yet.




The other big thing these entry level solar scopes offer is their ease of use. You only need to worry about getting focus right and then you move the etalon which changes the tuning of the Ha wavelength to see different features, you can move the etalon to see anything from a basic sunspot disc to the full blown active sun with prominences and filaments which often change shape over a single session of viewing. Basically you just twist two dials and that is it, once you have focus everything falls into place. Another bonus of a scope like the Coronado PST at least is you can mount it on a regular inexpensive camera tripod with no need for an astronomical mount which can be cumbersome and less portable.

You can if you so desire modify the PST to effectively increase the size, power and resolution of this scope using a donor scope and ERF filter and a bit of know how. This effectively increases the resolution of the scope and the detail that can be seen increasing the size of the telescopes aperture. The ability for the PST to be modified later down the track has made this scope a popular choice when considering which one to choose and a real no brainer option for those who do get one. The same principle suggests this could be done with the Lunt’s too but I'm yet to hear of one being done.

Imaging in Ha

This is the area where the Hydrogen Alpha scopes really shine and provide you with those great images of the sun that people get accustomed to seeing. What you see through the scope is not the same as what you see in the processed images, the detail is all there but after processing is when you really get the best out of your images.

The thing though with this is there is no easy and cheap option for getting those professional looking images(well there is but the quality doesn't hold a candle to it). To get the most out of these scopes you need to be using a ccd camera and they don't come cheap. It is also recommended to use a mono(black & white) camera too as it saves the hassle of splitting the colour channels in processing later and the same principle applies as with the webcams, their advantage being you can take many single images of a high quality in a short time frame and then stack them. But at the end of the day it will allow you to get pictures like these and the ones posted at the start of this section. You can even take videos.






With that said you of course can use other types of cameras with Ha scopes to take reasonably good pictures using webcams and DSLR's but the image quality drops off and you may find it's not giving you the results that you would like. But I always say never let that hold you back, just use whatever you have at your disposal and it certainly is satisfying to produce any image yourself and you also pick up techniques that may be useful elsewhere.

Conclusion

Hydrogen Alpha telescopes are by a long way the most exciting format that you can view our Sun with, they give you spectacular views in real time and in a perfectly safe way of doing so. Yes they can be pricey but are now catering for amatures with good quality entry level scopes. I highly recommend these scopes for both people with a serious interest and those who just want to enjoy looking at the sun. I also recommend if possible to look up and find your local astronomy club/society and enquire if they run a public viewing solar day and to go check them out, you'll be glad you did.



posted on Oct, 26 2011 @ 07:44 PM
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Safety comes first

In addition to the warning giving at the top of the thread I feel it is neccessary to reiterate that safety needs to come first when you are viewing the sun, you only have one set of eyes and damage in most cases is irreversable. It's not hard to follow some basic rules and not risk your health.
You also have to remember that you wont always feel any pain if your retina is burning and any effects may not show up for hours after so just because there is seemingly no ill effects does not mean damage is not occuring.

solar-center.stanford.edu...
news.bbc.co.uk...
eclipse.gsfc.nasa.gov...
www.nature.com...
news.bbc.co.uk...
www.suntrek.org...

This section is not designed to scare anybody but it is essential that you are aware of it and as peviously mentioned, if in doubt seek advice from experts(your local telescope dealer or asto club) and they can explain further.

I think that the major points are...

    -Never look directly at the sun with the naked eye.
    -Never look at the sun through the binoculars or telescope eyepieces without an approved solar filter fitted.
    -Always check filters for scratches or pinholes before starting an observing session.
    -Always read carefully and follow the manufacturers instructions.
    -Only use approved and tested solar filters and always get them from reputable dealers.
    -Never use a substitute filter, just because something seems dark does not mean it can block out the harmful rays.
    -Always use extra caution when viewing with children.


One last warning is that there are some cheap eyepiece filters doing the rounds that are sold as solar filters but are nothing but dangerous, please avoid them at all costs. A solar filter never attaches to the eyepiece always the front of the telescope.
Here is a good link and videio showing what happens when you use these filters.

astunit.com...


However all the methods mentioned above are perfectly safe if used in the correct fashion, there is no need to be afraid of the solar viewing if you are doing it correctly.

Wrap up

So there you have it, a basic an introductory run down of things. I tried to cover the most common ways of observing the sun and hope to have at least raised awareness of an extremely interesting branch of astronomy. There is something for everyone to have a go at regardless of budget or experience and it is a rewarding experience viewing our closest star.
I deliberately have tried not to get too technical or explain the inner workings of every little thing otherwise this would be longer than it already is and wanted to keep things as straightforward as possible.

There are also a few other methods I have missed like CaK(Calcium) and NUV(Near Ultra Violet) but seeing as they are mainly used for imaging and you have trouble visually seeing I left them out, although if need be it can be explained.
I also know I have probably missed some things out that should be said too, so please add to the discussion and the thread as this is a fascinating subject and more information can only be a good thing.


Some cool links.
thesuninmotion.com...
dailysolar.weebly.com...
www.thefirmament.nl...


edit on 26-10-2011 by pazcat because: (no reason given)



posted on Oct, 26 2011 @ 08:01 PM
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This guy would argue that you don't need any protection to view the sun





posted on Oct, 26 2011 @ 08:39 PM
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thanks my kids will love it.



posted on Oct, 27 2011 @ 04:01 AM
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reply to post by outandopen
 


That's alright.
Kids normally do get a kick out of easy projects and it teaches them at the same time as having a bit of fun.



posted on Nov, 7 2011 @ 04:14 AM
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What a fantastic thread.

Thanks, man!



posted on Nov, 7 2011 @ 04:26 AM
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reply to post by Awen24
 


No worries

I thought it'd be nice to show people that it's easier than some may realise and safer.



posted on Nov, 18 2011 @ 03:13 PM
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Sorry I only picked up on your thread now....

Having a white light filter for your binoculars, or telescope is so nice. you can view sunspots, eclipses, transits of Venus and Mercury, etc.... My first white filter was a mylar film from eclipse-glasses, pasted over a small hole in the lens-cap of my camera, lol ..... but I did manage to get good pics of a total solar eclipse over Zimbabwe in 2001.

Nowadays I have a nice white light filter on my telescope, and have recently acquired a 60mm Ha telescope, but by then the good weather over Norway was gone, and now I can't even see the sun anymore
, at times like this I long back to Africa with its clear skies 360 days a year, lol .......



posted on Nov, 21 2011 @ 06:33 AM
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reply to post by Hellhound604
 


That's alright.

I tend to make my own white light filters using baader film, it's easy enough to do and relatively cheap. I need to make another up over winter I think.

I'd love a 60mm Ha scope but they are a bit pricey, although with the PST mod I'm getting the bits for you can effectively double the arpeture to 80mm but that's another project to add to the list of things that will never get done.
I thought I had issues with lack of Sun here but Norway wouldn't be the best, I wont complain about getting a couple of hours a day any more.





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