Solar Observing fear

[azrabella]

I think the title says it. I have a somewhat pathological fear of looking through the eyepiece of any optical device which is pointed at the Sun - so what I am asking is just how safe are solar filters? It seems that one requires an awful lot of faith in a flimsy piece of mylar saving you from permanent retinal damage - feels like a game of Russian roulette. Any Solar observers remember their first time?

[David Smith]

If you have that level of concern then it's probably not worth the stress, especially with the current low (non-existent) levels of activity. Suffice to say there are lots of solar observers and imagers on this and other forums who manage to observe on a regular basis without injury. I used mylar film for many years without injury and my children also enjoyed the views. So long as you are careful there is no reason why you should come to any harm observing our star.

[johninderby]

Perfectly safe if you use common sense and pay sttention to the details. Inspect the filter for damage first then make sure it is securely attached. The Baader film is surprisingly tough. Also a few small pinholes in the film are not dangerous but you don’t want cuts or bigger holes.

http://www.baader-planetarium.de/sektion/s46/download/aS-Folie-Beilage-S2-e-A4-LR-0409.pdf

A Hersechel wedge is the safest but far more expensive and only suitable for refractors.

[vlaiv]

I would not say I had fear, but a healthy dose of caution and respect for potential hazard.

What helped me was naked eye view thru filter - just take it out on a sunny day without being attached to telescope, hold it against the sun and look thru it. There is fraction of a second before looking at the sun becomes very unpleasant and you have to look away, so its fairly safe to do it thru filter - you can instantly look away on any sign of discomfort. It tuned out that there was absolutely no sign of any sort of discomfort and view was pretty pleasing and interesting. This way you can also inspect filter for integrity and any micro holes / cracks in it (I did not find any).

Next thing that you can do to put your mind at ease is to setup your scope and filter, put in eyepiece but don't look thru it yet. Make sure your eye piece is focused - you can do this without filter by pointing it to far object - of course be careful not to point it anywhere near Sun. Or you can do it by holding your hand against the eye piece and seeing sunlight being concentrated in a bright spot - well I did that as well - instead of putting my eye in "harms way" - I first went with skin to see if I would feel any sort of sensation - expected maybe a bit of heat if all was not well. Nothing happened of course, and brightness of sun image was not that great as to cause concern. 

You can use these trick both to put your mind at ease - properly using solar filter is quite safe, but use these as means of making sure / double checking that it indeed is safe.

[Stu]

I observe the sun using a Herschel Wedge, which to me is a more fail safe method because if the wedge falls out, all you risk is a hot leg!

Observing the sun should always be approached with care, so you are right to be concerned. Following a careful setup routine will help to avoid mistakes, most importantly always check that the film is not damaged in any way, no pinprick holes etc, plus always make sure it is securely fastened so it cannot blow off in the wind etc. As important is making sure the scope is not left unattended to avoid anyone less experienced, or children for instance placing themselves at risk.

With care though, solar observing is highly rewarding and an area which I’m very glad I have got involved with.

[Thalestris24]

Another option might be to connect a suitable camera in place of an eyepiece and do solar eaa or use a Herschel wedge as Stu says (are they any good? What can you see?) . But... you don't see much in white light anyway (just sunspots) and it's still pretty much solar minimum at the moment. Otoh, proper solar scopes are very expensive. You can always view the sun near live through various filters online eg SOHO.

Louise

[Sunshine]

I have used the thin films forever before i had a solar scope, just use caution like making sure the film is secured to the scope properly, buying from a reputable seller and brand, and be sure to inspect it before use.

i have never in my life heard of someone injuring themselves, the one you should never ever use is those old eyepiece glass filters that screw on to eyepieces, those can crack under heat.

[SIDO]

A smartphone camera and adapter provides a nice safe live view in white light and is my preferred method not out of safety concern but just because the live view is as good as what I'm seeing in the eyepiece, I often do this for the Moon too as these two objects are both really representative of what's seen in the eyepiece when viewed on a smartphone...too bad there aren't more objects like these up there ?

[wookie1965]

I had one of these on my 6" reflector I photographed the Mercury Transit with it no problem. https://www.365astronomy.com/Solar-Filter-for-150mm-Newtonian-Telescopes.html

I now have the solar wedge which is even better but that is only for Refractors. https://www.365astronomy.com/Lunt-1.25-Inch-White-Light-Herschel-Wedge-Solar-Wedge-with-Integrated-ND3.0-Filter.html

Just remember to keep the end caps on the finder scope and your good to go.

[RT65CB-SWL]

As long as you check your solar filter for any defects, i.e. tears, small holes, pin-pricks, etc., before each and every use; and attaching to your binoculars, telescope, or even camera lens, white-light solar observing is perfectly safe. Even glass solar filters need to be checked for defects before each and every use.

Never use glass solar/sun filters that screw into the nosepiece of an eyepiece.

[Stu]

6 hours ago, Thalestris24 said:

or use a Herschel wedge as Stu says (are they any good? What can you see?

Not 'arf! Whilst you can essentially see the same features as you can with solar film, a Herschel Wedge gives a brighter images and in my experience shows more fine detail at high power.

The sun is very quiet at the moment, but whenever there is an active area I find white light observing a very rewarding aspect of the hobby.

[niallk]

I looked with my left eye my first time (right dominant)

[michael.h.f.wilkinson]

I have never had any problems with any proper solar filter, even ones with a well-made DIY cardboard holder. I do have a strict routine of first pointing the scope to the celestial pole, then removing the front cap, then checking and attaching all required filters, checking they are firmly attached and only then swinging the scope to the sun. When finished I first swing the scope back to the celestial pole, and then unmount the filters, attach caps, etc.

[Thalestris24]

9 minutes ago, Stu said:

Not 'arf! Whilst you can essentially see the same features as you can with solar film, a Herschel Wedge gives a brighter images and in my experience shows more fine detail at high power.

The sun is very quiet at the moment, but whenever there is an active area I find white light observing a very rewarding aspect of the hobby.

I've done some white light/ solar film imaging but have found it a bit underwhelming. Using a proper solar h-alpha filter has always seemed a bit more interesting (going by others' images). White light when, as at the moment, there are no (or very few) sunspots is - meh! (Just my opinion). As I mentioned, looking at the soho online images is quite good, free, and independent of the weather

Louise

[Cosmic Geoff]

I am surprised that nobody has mentioned the safest method of observing the sun in white light - project the image onto a piece of card.  You do not look through the eyepiece.  This is one of the classic methods of observing the sun and shows sunspots, and I also observed a transit of Mercury by this method.

Notes: for projection, it is best to use an aperture of 4 inches or less, and a diagonal helps keep the card in shadow. Make sure the eyepiece has no plastic components as these are liable to melt if the sun's image goes off-axis.   Cover up any optical finder or avoid looking through it.

[Moonshane]

Looking at the sun is highly dangerous and counter-intuitive - without proper filtration. Getting hot metal out of a furnace is highly dangerous - without proper gloves.

You need to keep in mind how dangerous it can be whenever observing and setting up your kit but used properly, there is literally no more danger from looking at the sun than looking at the moon - using the correct filters. The main dangers with the film are that you can accidentally damage it (although it is tough) or the filter can accidentally be knocked or blown off if not securely place on the objective end.

Personally, I prefer the Herschel wedge which is not that expensive (£100-150 ish to a 1.25" version) as it is safer in respect of the above issues and also offers more detail in good seeing.

Ha observing is even safer as you look at a single(ish) wavelength which is not damaging to the eyes.

There really is nothing to fear as long as you think about what you are doing each time and avoid complacency.

[LukeSkywatcher]

I was a bit nervous when i first used a "bit of tin foil" to look at the Sun. I knew people here on SGL would not see me wrong, so i took comfort from that. I made my own filter from a sheet of the "foil". I am rubbish at these type of DIY projects so i didnt keep the filter long. I then bought a Hershel Wedge for white light observing.

White light observing is great but can be underwhelming, so about a year ago i invested in a Daystar Ha filter.

[cletrac1922]

What sort of scope you have

For a dob, the hard plastic cover has a small removable cap, and you sticky tape Baader visual film underside, and attached the hard plastic cover to top of the dob

Leave off the spotting scope, although have made up a filter also for mine

I have a glass filter for my ED80

Attached image was taken holding my mobile phone to eyepiece, using Baader visual film on my dob

Image of ED80 with solar filter

John

[Merlin66]

Just a correction:

The solar safety films used today are not a "piece of Mylar".....

They are sophisticated coated polymer film with excellent optical properties and consistency. I use the Baader Solar film which is 110% safe to use.

https://astrosolar.com/en/information/about-astrosolar-solar-film/differences-in-astrosolar-solar-films/

 

 

[Charic]

On 27/11/2018 at 23:16, Stu said:

I observe the sun using a Herschel Wedge

Every days a school day,  and tonight I learnt something new?

My first scope was held in place with a GEM ( German Equatorial Mount ) and after one session, I decided this was not the mount for me, making the  quick decision to go with a Dobsonian mount, which is perfect for my needs.

Therefore, showing very little interest in any other type of mount, whenever this wedge was mentioned,  and without investigation, I honestly thought it had/was something to do with the head of the mount?..Doh! 

 

[Les Ewan]

I first observed the Sun back in the early 70's with small refractors projecting the Sun onto white card.Telescopes in those days were supplied with cheap Kellner or Huygen eyepieces which seemed to work well with the heat involved in the method. I wouldn't risk putting modern eyepieces and telescopes through such torment nowadays.

I use baader film entirely now,and have made my own full aperture filters for my 90mm refractor and 7X50 binoculars and as long as these filters are well made ,secure and are checked regularly they are quite safe.

My cheapest simplest system is a square of Baader  duct taped over the off axis aperture of  my 200mm Newtonian dust cap,not only is it very safe its easy to check before each use. Although my cap is a tight fit I also tape it to the tube as well just to be on the safe side.

[Wyvern]

Interesting that no one's picked up on these beasts! 

Maybe it's just me that has a hatred of these cheap and potentially lethal - to your eye at least - "solar filters" that screw into the eyepiece of 1.25 inch ep's.

A number of cheap "starter telescopes" often feature a "Sun filter" and "moon filter" as accessories with their scopes to make them more "attractive" to potential purchasers. While the moon filter will be of some use at times in the Lunar cycle and cut down glare, just think for a moment where the filter is actually placed in the focal path. Yep, almost at the exact point where all the light and heat is brought to a focus. Given time, the "solar filter", having gone through periods of heating (expansion of filter material) and cooling back to ambient storage temperature (contraction of filter material), will suddenly and without any warning crack and fail, leaving your now unprotected eye ready to instantly lose its sight having had the "benefit" of all the aperture and magnification capacity that your telescope can supply.

If anyone has one of these "solar filters" with a telescope, please, for your own safety and peace of mind throw it away - after beating it senseless with a hammer - and follow the safe and sensible options presented in the posts above.

Thanks,.......... getting off my soapbox now!!!

Les

[Stu]

18 minutes ago, Wyvern said:

Interesting that no one's picked up on these beasts! 

Maybe it's just me that has a hatred of these cheap and potentially lethal - to your eye at least - "solar filters" that screw into the eyepiece of 1.25 inch ep's.

A number of cheap "starter telescopes" often feature a "Sun filter" and "moon filter" as accessories with their scopes to make them more "attractive" to potential purchasers. While the moon filter will be of some use at times in the Lunar cycle and cut down glare, just think for a moment where the filter is actually placed in the focal path. Yep, almost at the exact point where all the light and heat is brought to a focus. Given time, the "solar filter", having gone through periods of heating (expansion of filter material) and cooling back to ambient storage temperature (contraction of filter material), will suddenly and without any warning crack and fail, leaving your now unprotected eye ready to instantly lose its sight having had the "benefit" of all the aperture and magnification capacity that your telescope can supply.

If anyone has one of these "solar filters" with a telescope, please, for your own safety and peace of mind throw it away - after beating it senseless with a hammer - and follow the safe and sensible options presented in the posts above.

Thanks,.......... getting off my soapbox now!!!

Les

A good reminder Les. I think somewhere around there is a video of one of these awful filters cracking in the sun, best smashed and thrown away as you say!

[John]

5 minutes ago, Stu said:

A good reminder Les. I think somewhere around there is a video of one of these awful filters cracking in the sun, best smashed and thrown away as you say!

I think this is the one Stu: