I want to buy a solar filter, which one?

[Lotinsh]

I want to buy a cheap solar filter so I could take photos of sun, but does quality matter? And what to look for? 

Edit: I'm thinking of buying this, but is it a good choice?

https://www.amazon.de/-/en/Solar-Filter-Telescopes-Binoculars-Cameras/dp/B01770FDAC/ref=sr_1_6?dchild=1&keywords=solarfilter&qid=1625365661&sr=8-6

Edited July 4, 2021 by Lotinsh

[Franklin]

Thousand Oaks are a reputable solar filter supplier, so yes this would be ideal. If DIY your own filter be sure to follow the instructions carefully and don't stretch the film too tight.

[Stu1smartcookie]

I bought a glass filter only the other week . Bought from one of the main astronomy retailers who gave me advice . It’s an important purchase after all .  So, maybe call or email either Rother Valley optics or the sponsors of this site First Light Optics . They will give you advice . Whilst some solar filters are less expensive , like most things you generally get what you pay for . But with solar filters it’s imperative to get it right . 

[johninderby]

Go for a solar filter with Baader solar film. Better than the Thousand  Osks filters. Stay away from the glass solar filters as they use cheap glass that isn’t optically flat. Optically flat glass is ridiculously expensive so isn’t used nowadays for solar filters.

Astrozap or Kendrick make excellant premade filters.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p547_Baader-2459281---Astro-Solar-Safety-Film---visual-ND-5-0---200-mm-x-290-mm.html

Edited July 4, 2021 by johninderby

[Neil H]

I have a Kendrick filter for my 8 inch very nicely made views are good I did read that Kendrick make solar filters for NASA so you won't go wrong as John said Kendrick or baader 

[nfotis]

If you plan on building your own, Baader Astrosolar film is probably the best. It's available in A4 and larger sheets, which can be easily cut to various scope sizes.

There are two versions: for observing (most safe) and for photography (more detail), select according to planned use.

N.F.

 

[Tiny Clanger]

+1 for the Baader solar film, unlike the filters which come with Bresser 'scopes, it does not give the Sun a yellow cast. One sheet (they are slightly less than A4) made filters for my 127 mak, my ST80 (full aperture) and two small filters suitable for the aperture mask built in to an ST80 dust cap.

The Baader film has been used by many for years, so I trust it to keep my eyes safe, and I feel it is an advantage that it is relatively cheap, as I'd never be tempted to keep using a damaged one , replacing it would be financially painless.

Heather

[badhex]

+1 for Baader. They also do pre-made filters with a rigid plastic disc, rubberised pegs and velcro safety straps (I have this one). 

[Carbon Brush]

Everything said in the above posts about filter choices is valid advice.

However, I would add a caution about purchasing.

By all means by a Thousand Oaks or Baader filter, but buy from an astronomy retailer.
That way there is no doubt about the provenance of the product.

You don't get two chances looking through a telescope at the sun. Is your sight worth the risk?
Stay with a local astronomy retailer. You have no risk of buying the 'almost' product.
By supporting these people, you help ensure they are there when you need advice on other astro kit.

HTH, David.

[RT65CB-SWL]

Avoid this type of screw-on filter like a pandemic/plague.

[johninderby]

7 minutes ago, Philip R said:

Avoid this type of screw-on filter like a pandemic/plague.

Apply the following several times to said eyepiece solar filter.

Edited July 4, 2021 by johninderby

[Lotinsh]

Thanks guys, I'm going to buy the Baader filter, I mean if nasa uses it what could go wrong? Thanks for the amazing advice, I'm looking forward to taking some amazing shots of the sun hopefully!

[Clarkey]

3 hours ago, Lotinsh said:

I mean if nasa uses it what could go wrong

Mmmm. Not sure this should be considered a selling point🤣. I remember a big telescope they built with a wonkey mirror - now was it inches or mm's.............??

[Lotinsh]

Wasn't the wonky mirror the hubble's telescope's? I remember reading something like that and they fixed it by putting a reversed form converter lens to correct the wonkyness 

[mikemarotta]

22 hours ago, Lotinsh said:

I want to buy a cheap solar filter so I could take photos of sun, but does quality matter? And what to look for? 

 

First and foremost "cheap" is not what to look for in a solar filter. REPUTABLE is the key. You did well by asking here first. 

QUALITY is essential as you can be blinded. 

Second, do not buy from Amazon. They are fine for books and housewares or whatever, but with astronomical instruments you want someone who will support your purchase. This site is sponsored by a retailer, First Light Optics. I would start there. But there are others, of course, depending on where you live, import duties, etc., etc.

Also, many people claim that Baader is superior to Thousand Oaks. Everyone has opinions. One reason why is that Baader film shows a white solar disk, whereas Thousand Oaks shows an orange disk. But, the Sun is not white. The Sun actually emits more in the GREEN band. Why not have a green filter? All you want to do is to filter the light for your own safety.

I bought these from Explore Scientific, also sold in Europe through their partner, Baader. They come in three sizes.

They are pre-made to fit your telescope with your own handiwork at putting them together. I also tried it out immediately by looking at the Sun just naked eye. Seems fine. I have used it since with my smallest telescope. I just recut the mounting to fit my mid-size instrument. (Explore has a video showing how to do the work. The printed instructions are totally graphical.)

Let us know what you decide.

 

 

 

[Spile]

I made mine using a sheet of the Baader Film, a couple of sheets of art card and some foam card https://astro.catshill.com/solar-filter/

[Stu1smartcookie]

23 hours ago, Lotinsh said:

I mean if nasa uses it what could go wrong?

Where do we start with this ?

Please remember that , whatever you buy , its not indestructible  . As long as you are buying from a reputable site then you are more than halfway there . 

 

[Lotinsh]

Yea, I probably framed it wrong, I meant what could go wrong in terms of product's quality, that if nasa uses it then it must be good no doubt, but anyways, thanks for the great responses, I will order this one from my country's store and I'll leave an update once I receive it and take some lovely photos. Thanks! https://www.ieskaties.lv/teleskopi/saulei/baader-planetarium-a4-20x29-cm-saules-filtrs

[Neil H]

 Kendrick filters are made of baader solar film

https://www.kendrickastro.com/solarfilters.html

Edited July 5, 2021 by Neil H

[wulfrun]

A couple things that no-one has mentioned...whatever you choose make sure it is attached securely and check it for damage before EVERY use. A gust of wind or a careless knock MUST NOT dislodge it. Tape, velcro, 2 elastic bands (not 1) etc but something secure, regardless.

(EDIT: if you're ONLY taking photos, your worst risk is "only" equipment,  rather than your eyesight, so you can be less strict.)

Edited July 5, 2021 by wulfrun

[LukeSkywatcher]

On 04/07/2021 at 15:38, johninderby said:

Apply the following several times to said eyepiece solar filter.

Other branded hammers are available.

[LukeSkywatcher]

The Badder Astro filter will only let you see the Sun in white light. You will also see Sunspots. To see the Sun in others way and more details you will have to pay more, such as Quark Chromosphere filters and the likes. You said cheap.....so Bader astro is a great start.

[Starslayer]

This has worked very well for me and is also very secure.  No good if it does not match your scope but does your maker do a bespoke one maybe?  gets lots of use too as the nights have been so rubbish recently. 

https://www.harrisontelescopes.co.uk/acatalog/celestron-eclipsmart6.html

[michael.h.f.wilkinson]

On 04/07/2021 at 10:03, johninderby said:

Go for a solar filter with Baader solar film. Better than the Thousand  Osks filters. Stay away from the glass solar filters as they use cheap glass that isn’t optically flat. Optically flat glass is ridiculously expensive so isn’t used nowadays for solar filters.

Astrozap or Kendrick make excellant premade filters.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p547_Baader-2459281---Astro-Solar-Safety-Film---visual-ND-5-0---200-mm-x-290-mm.html

This perpetuates a recurring myth that glass filters are not figured properly optically, because this is somehow far ore difficult than figuring a spherical surface (or even a paraboloid). You are confusing an optical flat used to test the figure of optical components, and has to be flat to within 1/200 lambda typically, with plane-parallel glass needed for filters (where 1/10 lambda is sufficient). The latter are no more expensive than your typical UV/protection filter for camera lenses, or the corrector plate of my SCT (which is actually harder to figure).

I do agree that glass solar filters are far too expensive, given the availability of solar film of the same or even superior performance. Glass filters are more durable, as a rule, but then replacing a damaged piece of solar film is so cheap that you could probably replace the filter ten times for the cost of one glass filter.

[Stu1smartcookie]

2 minutes ago, michael.h.f.wilkinson said:

This perpetuates a recurring myth that glass filters are not figured properly optically, because this is somehow far ore difficult than figuring a spherical surface (or even a paraboloid). You are confusing an optical flat used to test the figure of optical components, and has to be flat to within 1/200 lambda typically, with plane-parallel glass needed for filters (where 1/10 lambda is sufficient). The latter are no more expensive than your typical UV/protection filter for camera lenses, or the corrector plate of my SCT (which is actually harder to figure).

I do agree that glass solar filters are far too expensive, given the availability of solar film of the same or even superior performance. Glass filters are more durable, as a rule, but then replacing a damaged piece of solar film is so cheap that you could probably replace the filter ten times for the cost of one glass filter.

agree 100% ... my glass solar filter cost £70 but i am delighted with it . Yes , i know if i drop it , it will break ... but , thats down to me , nothing to do with the construction of it . Its an expensive option in an expensive hobby . I for one am happy with the advice i received from a very reputable Astronomy company . I really do get why people wax lyrical regarding Baader film. But i am a bit perplexed at the hostility ( probably the wrong word to use ) of glass filters . 

I am pleased for @Lotinsh that his question has provided such a great response . A lesson for all , if in doubt , ask ... then sit back and enjoy the fireworks