welding glass and the sun.

[Andy78]

Hi all... i watched the eclipse through a welding shield, safe enough!!! But would it be safe enough to graft one of these masks to the hole in the dust cover of my newt to observe the sun???

Its probably a stupid question.. but may have been more stupid to first try without asking!!!

Thanks in advance... Andy

[cathouse42]

http://eclipse.gsfc.nasa.gov/SEhelp/safety.html

Does #14 welding glass block UV and IR also?

Found some charts for #14 glass

https://www.rasc.ca/tov/safety

https://www.rasc.ca/sites/default/files/tov-chou-welder14-safe-500.jpg

[LukeSkywatcher]

I'm going to say that observing the eclipse through a welders mask may have been safe(ish) because there was/is zero magnification. I really would not be putting one (the glass) over a scope. 

No. Dont do it. All it will do is dim the brightness. I doubt it will take away the intense heat and harmful UV light.

[Bizibilder]

I would say an emphatic NO!  You have no idea what wavelengths of light (including uv and ir -  these can both cause eye damage) that any particular welding glass would transmit.

Baader Solar film ND5.0 is less than £20 a sheet and is guaranteed to be safe for both visual or photographic use. You only have one pair of eyes and any mistake and the Sun WILL blind you - no second chances.

You can get the film here: http://www.firstlightoptics.com/solar-filters/baader-astrosolar-safety-film-nd-50.html    (usual disclaimers)

[cathouse42]

I would say an emphatic NO!  You have no idea what wavelengths of light (including uv and ir -  these can both cause eye damage) that any particular welding glass would transmit.

Baader Solar film ND5.0 is less than £20 a sheet and is guaranteed to be safe for both visual or photographic use. You only have one pair of eyes and any mistake and the Sun WILL blind you - no second chances.

You can get the film here: http://www.firstlightoptics.com/solar-filters/baader-astrosolar-safety-film-nd-50.html    (usual disclaimers)

Well, you would get a second chance, just not a third.

[Andy78]

I agree with you luke. Ive just read sommat on the interweb saying the same as you!!! I guess its baader film then.

[LukeSkywatcher]

Honestly, this stuff is the cheapest and safest way to observe the Sun. It blocks (i think) about 99.999% of the harmful stuff.

http://www.firstlightoptics.com/solar-filters/baader-astrosolar-safety-film-nd-50.html

What scope are/will you be observing with?

[Qualia]

As Luke and Roger have emphatically said: you do not get second chances with solar observing, so why take the risk or cut corners  

If you do not know a filter or procedure is safe, or if others are saying: "listen, mate, don't go down that route!" Then do not use the procedure, filter or route! When it comes to observing the Sun, always err on the side of safety. An eye once damaged is forever damaged. It's that simple!

Recal the three S's for solar work: Safety, Seeing & Suitable gear from reputable sources

[Ibbo!]

No

Its not worth the risk

[slim80]

Baader astro film is a must.Making a solar filter is easy.Ive made one myself recently and had some great veiw's of the Sun.

As fellow members have said do NOT use the mask.

[DaveS]

NO!!! Not nohow never!

Use the stuff designed and certified for the job. End of!

[Andy78]

Thanks to all. And i totally agree with safety first. This is why i didnt just go ahead and observe with the mask/screen!

Luke... ive got a generic newt, 150/750 F5. Its very similar in looks to a TS Optics bur mine has no markings to indicate either way. The secondary is a tad on the small side so collimation was slightly difficult at first. But i got it sorted and it works a treat. I had to sell my SW 250PX Dob due to my car needing fixing. But just before this i saw my present scope on ebay and took a punt with £30 and its e great scope on an eq3 mount. When i can upgrade again though, im going for the 200p on eq5. Simply because i prefer an eq mount to dob base.

[Bizibilder]

There is another warning to be added for those using a Newtonian / SCT / MAK (or anything with a "secondary" mirror or surface).  You should always use a "front end" full aparture filter with these scopes as you are focussing the light and heat of the Sun onto the secondary.  This will heat it up and can cause it to either shatter or, for those that are glued in place, for the glue to fail and the smaller mirror to drop down the tube and hit the primary.

[Pig]

Enough said really, but this is one scenario to think about.

[cotterless45]

Unfortunately I still see on ebay scopes the old style glass "Sun filter". I make an effort to contact the seller to amend their item by binning the filter. Hopefully this will do some small good.

Nick.

[Roysten]

During the recent solar eclipse one of the guys at work tried looking at the sun through a welders mask,didn't get overly blinded but still wasn't ideal, and that's without magnification. I looked at it through 16 layers of sheet filter in order to make it bearable and hopefully safe (I can still see so hopefully it was ok). Like people are saying it's not worth trying it, I'd get some proper kit!

[cathouse42]

During the recent solar eclipse one of the guys at work tried looking at the sun through a welders mask,didn't get overly blinded but still wasn't ideal, and that's without magnification. I looked at it through 16 layers of sheet filter in order to make it bearable and hopefully safe (I can still see so hopefully it was ok). Like people are saying it's not worth trying it, I'd get some proper kit!

It was probably not #14 glass then he used.

Probably something more transparent

Wasn't the last solar eclipse cloudy anyway? 

The last solar eclipse wasn't that impressive, it was partial, what was more impressive was the high contrast images I could have taken of the surrounding area. Very like golden hour

[Zakalwe]

Of course a welding glass will block UV and IR. If it didn't then every welder in the world would have cataracts and cooked eyeballs!!

However, if you were using multiple layers, then they weren't arc welding filters.....probably gas welding screens.

Welding filters are made of toughened plate glass though and are optically pretty poor.

Don't mess about though. Get some proper Baader Solar film. Is that's too costly for you then don't do solar observations. Simple as that. Eyes are too precious to mess about with. How would you feel if you spent the rest of our life with severely damaged eyesight just to get a fleeting glimpse of the Sun?

[Andy78]

So with the solar film! Do you need to use multiple layers when making the filter? I can see the benifits if you dou? Just want to know so i can do the maths for a full aperature filter and how many sheets that i would need? I can then find out if its cost effective at the moment cos im off to turkey for 15 nights on 6 weeks and the misses might not enjoy me splashing out the moment lol.

[Bizibilder]

No - the solar film is used as a single layer only, for any aparture.  You need the ND 5.0 film if you intend to do visual work.  ND 5.0 is also perfectly OK for photography as well.

The ND3.8 film (some suppliers sell it) is only for photographic use and cannot be used for visual work.

You have a 150 mm Newtonian so a single sheet will be enough to make a full aparture filter - you can use the left-overs to make a mini filter for your finder if you have one.  Alternatively remove the finder before pointing the scope at the Sun - you can give yourself a nasty burn if the caps are off!!

This link shows you how to make a holder (If you have scissors and glue DIY skills).  http://www.baader-planetarium.com/sofifolie/bauanleitung-objektivfilter-en.pdf

PS When you get your film remember that on one side of it there is a thin sheet of clear plastic, presumably as a protector of the film itself - Don't forget to remove it before making your filter!  It is very easy to miss it.

[Marky1973]

Get the film, it is easy to use. I built a filter for a 200p dob with one sheet, you can see how I did it HERE:

Just take care when handling the film. I was making a smaller version for my ED70 just last night and my works surface was not clean as I found some very tiny holes in the film, so light was getting through - luckily, just when shining a torch at it, rather than the sun! Gonna get some more as it is a great price and works perfectly. You don't even need to get the film perfectly flat.

[Andy78]

Thanks bizibilder for the link and to marky1973 for the advice about clean work tops. I probably would have over looked that with the excitment of building the filter. And thanks to everyone else too, youve all been very helpful

Cheers.... Andy

[Bizibilder]

If you work on a clean table with a decent surface to start with then place a fresh piece of soft kitchen paper down first and work with the film on that.  When making my filters (I've made several) I found that with care there is no need to touch the filter sheet with your fingers at all.  I wore soft cotton gloves (new and bought for the purpose) but simply wrapping your finger in a piece of kitchen paper when you do need to "touch" the film works well.  The trick is to understand what you are doing when constructing the holder and to work slowly and methodically, one step at a time.  It is not difficult to make a really neat job of it.

To cut the film it is worth getting a nice new sharp pair of scissors - haberdashers stores sell dressmaking scissors that will do the job perfectly.  Blunt scissors are worse than useless as they will damage the film.

[Andy78]

Cheers for the tips and methods bizbilder.

[Pig]

I have not read all the posts, but one thing to mention just in case is :-

The film does not need to be taught like a drum skin when its in place, in fact its better to have it slightly loose as you know it hasn't been compromised by stretching, any wrinkles in the film will not affect what you see in the slightest