Solar filter - Baader vs Seymour / Film vs Glass

[Sonicfishcake42]

Good afternoon all you wonderful people! 

Got a couple of comparison questions for ya! I'm wanting to buy a relatively inexpensive solar filter for a C9.25. I'm ideally looking to spend < £100.

There seems to be a few available on the market from different manufacturers and in different versions. So first off I'd appreciate any advice on the differences between film vs glass solar filters? I'd assume rigidity would only be half of the equation in working out which one to opt for? By this I mean will there be a difference optically between the two? Does the film distort the view with the creases? And with glass does this distort the view with it being thicker?

In addition to this, by looking at images of baader film on google the view of the sun looks whiter where as the Seymour looks more of an orange colour. Has this any affect of the quality/contrast or sharpness of the images?

I understand that is probably a rarity that anyone owns both or different versions of white light filters however I'm hoping one or two of you may have had the chance to look through both. Also, any comments on a brand that you use would be appreciated.

(The two I'm looking at are linked below)


http://www.rothervalleyoptics.co.uk/seymour-solar-sf1075-1075-type-2-glass-solar-filter.html

http://www.firstlightoptics.com/solar-filters/astrozap-baader-solar-filter.html

Thanks for any info in advance! 

Regards,

James 

[ronin]

Really a choice of glass or film, the 2 film options are just different characteristics, so Yellow/Orange or Grey/White.

Some say avoid glass no sure why as I have a glass filter and it is excellent, it produces a grey/white image. Used it on the SUNday event, no-one left screaming they were blinded.

You can make one, ala Valarie Singleton style. If you do they remember that the film just sits there it is not under any tension to remove creases/ripples. It may be sensible if you make your own to visit a craft shop and buy a couple of sheets of clear plastic and sandwich the film between. Bit of protection and keeps fingers off the actual film.

[Floater]

Hi, James. I don't own, and have never looked through, a glass filter. I have, however, read many threads suggesting that the glass filters are more breakable if dropped, for example. This seems to make sense.

I have three Baader film filters (different sizes for different scopes) and they all perform very well. The creases have no effect on the view and, if my memory serves me, Baader say that one should not try to eradicate them.

Film filters are also less costly than glass filters.

As for Seymour's claim that the 'orange yellow' colour is more natural, I think some would debate that point. My understanding is that white is the colour of 'natural' sunlight.

My recommendation would be the Baader solar film. If economy is part of your decision making you can buy a sheet of Baader film for even less than the ready-made filters and make your own. Might even be enough to make a filter for a finderscope, too.

Clear skies and sunny days (whatever they are!).

[Sonicfishcake42]

Hi Guys! Thanks for the info! I was leaning towards the glass filter on the notion that it would be more durable than the film. But dropping a film filter is obviously going to be less disastrous than dropping a glass filter. Budget wasn't too much of an issue between the two types, looking at it there's only a £20 difference and I'd rather buy a pre-made one than make my own (call me lazy haha). 

I didn't even think about the white light being more natural than the orange! Very good point actually. I personally don't mind which colour my view would be in, although it would be more pleasing to friends expecting an orange colour I think.

I guess it's really just a case of preference then!

Thanks again, 
James 

[David Smith]

I've only ever used Baader solar film and based on the reviews / forum posts I have read and images I have seen, I will stick with it. I have not seen anything that makes me think that any of the other filter types mentioned above come close to the level of detail you get from the Baader, in fact quite the opposite. The only way up from the Baader film really is a Herschel wedge.

[Davey-T]

I've only ever used the Baader Solar film DIY (see pic') some folks say that glass is less effective than the film.

£50.00ish pounds for a big enough sheet for full aperture SCT filter but you get enough left for a couple of refractors and some bino filters.

Doesn't matter if it's got creases in.

Dave

[Sonicfishcake42]

Great effort on the DIY job Dave! Looks great!

[Davey-T]

Great effort on the DIY job Dave! Looks great!

Thanks, mostly made of plastic cloaking strips used in double glazing and a sheet of white stuff ? from craft centre, I've since fitted some plastic thumb screws to keep it secured.

Dave

First image taken with it single DSLR shot

[Sonicfishcake42]

Thanks, mostly made of plastic cloaking strips used in double glazing and a sheet of white stuff ? from craft centre, I've since fitted some plastic thumb screws to keep it secured.

Dave

First image taken with it single DSLR shot

Sun13-12-14.png

Cracking job of it, I might have to get a pre-made one, my crafts skills are somewhat... non existent! haha. 

This is probably a daft question, do you know if the film you use is the same as the FLO astrozap versions? 

Did you add/adjust colour or is that the raw image? 

Cheers, 

James 

[Steve Ward]

Without question the Baader Solar Film is the best option .

 

Glass filters are not made from optical quality glass and are certainly not finished/polished to an 'optical' grade , they give an 'OK' view but a direct comparison with Baader shows up their lack of optical quality , especially at higher mags where the detail is definitely missing. 

 

They are also coated on one side only and invariably develop pinholes which need 'repairing' with a Sharpie on a regular basis.

 

And that's without the obvious question of durability , try accidentally dropping a glass filter and see how long it lasts ...  

 

Baader film is double coated meaning pinholes are rarely an issue as any holes that develop on one coating need to line up with a hole on the other side to become an issue .

 

And despite it's 'tinfoil' appearance the film is extremely strong , cannot be torn by hand , and bounces  ...  

 

 

The polymer based films such as Thousand Oaks or Seymour should be avoided at all costs , the view through them is dreadful in comparison and they should be reserved only for cheap eclipse glasses .

 

Interferometric data for Baader film ...

 

http://astrosolar.co...tric-protocoll/

[Steve Ward]

Really a choice of glass or film, the 2 film options are just different characteristics, so Yellow/Orange or Grey/White.

Some say avoid glass no sure why as I have a glass filter and it is excellent, it produces a grey/white image. Used it on the SUNday event, no-one left screaming they were blinded.

You can make one, ala Valarie Singleton style. If you do they remember that the film just sits there it is not under any tension to remove creases/ripples. It may be sensible if you make your own to visit a craft shop and buy a couple of sheets of clear plastic and sandwich the film between. Bit of protection and keeps fingers off the actual film.

I always say avoid the glass types based on my direct comparisons between them and Baader film , no question Baader won hands down both visually and more importantly for me imaging-wise.

I have never said they are not safe as you seem to imply above , but they do deteriorate over a relatively short time regarding the development of pin-holes that left unchecked/unrepaired could certainly cause a problem eventually.

As for sandwiching the film between two sheets of clear plastic to protect the film , forget it you'll kill any detail you might otherwise have seen , the A4 sheets come with a very thin clear protective film attached for transport , try viewing through the film without first removing this layer and you'll see how much a sheet of plastic will ruin the view , a quick search will flag this up as the main beginners problem regarding Solar Film , one that is regularly rectified here on SGL ... 

[Sonicfishcake42]

Noted, seems the Baader is certainly the highest rated with experienced users. Good to know, I was going to buy the 'Seymour Solar' filter. Took me a while before realising the very obvious (whether intentional or not) pun. 

Going to place my order for the Baader solar filter. Thanks all for your continued advice

James

[Steve Ward]

Wise choice sir , welcome to the "light-side" and enjoy the views ...

[Zakalwe]

You can make one, ala Valarie Singleton style. If you do they remember that the film just sits there it is not under any tension to remove creases/ripples. It may be sensible if you make your own to visit a craft shop and buy a couple of sheets of clear plastic and sandwich the film between. Bit of protection and keeps fingers off the actual film.

Baader specifically say in their instructions not to put tension on the sheet to remove any ripples.  Ripples have no effect on the view, whereas sheets of clear plastic will destroy it.

[Davey-T]

Cracking job of it, I might have to get a pre-made one, my crafts skills are somewhat... non existent! haha. 

This is probably a daft question, do you know if the film you use is the same as the FLO astrozap versions? 

Did you add/adjust colour or is that the raw image? 

Cheers, 

James 

Same Baader film I think, image from the camera comes out "monochrome" you can then play around and colour it in your program of choice, I use P'Shop

Dave

[Merlin66]

Over the years I've used many glass solar filters - they are OK but the optical quality is certainly not there. An "ideal" glass filterwould be 1/10 wave accuracy. I've never seen any glass filters advertising that....

The Baader solar film is 110% safe and IS 1/10 wave.

What more could you ask for? (Other than a Baader Herschel wedge on a big refractor ;-) )

[Steve Ward]

Over the years I've used many glass solar filters - they are OK but the optical quality is certainly not there. An "ideal" glass filterwould be 1/10 wave accuracy. I've never seen any glass filters advertising that....

There was a Carl Zeiss Jena glass-based Solar filter , the SFO-80 , was the only glass filter worth it's salt regarding optical quality.

Typically Zeiss in the precision of its glass and also in its price .

http://www.jena-fernrohre.de/0000009d6a0b61403/index.html

But even these were only coated on one side and developed pinholes over time ...

Baader film wins due to the fact that extremely thin materials do not diffract light to any noticable effect , even when not actually flat  ... ( hence no worries about the recommended slackly fitted , wrinkly film ... )

[Steve Ward]

Deleted ... unexpected double post ... 

[Sonicfishcake42]

Brilliant, glad I asked before jumping into buying a glass filter! 

Looking forward to giving it a try! A strange experience getting the telescope out in the daytime, my neighbours will think I'm nuts! Haha! 

And will have a play about on photoshop to play with the colour. 

How typical are sunspots? As in do they occur almost daily or is it more of a rarity to catch them? Images I see often have fewer than 6 spots with some even less.

Thanks guys 

[Floater]

You'll see sun spots regularly. Sometimes more, sometimes less, but there will always (well, nearly always) be something there to look at.

Two posts I await from you:

1. How do I 'find' the sun in my scope? Answer - there are many ways but a solar finder is best.

2. What's the best Herschel wedge? Answer - to be discussed.

Meantime, enjoy the light.

[Steve Ward]

They are long lasting features , typically around for weeks .

They pop up randomly from our perspective , some growing from nothing in the middle of the visible side while others develop far-side and emerge from behind as monsters .

The Sun takes about 27 days to rotate and some major spots have been known to survive 2 or even three full rotations , early 2014 for example.

For a quick hour by hour reference as to what's on view try here ... http://sdo.gsfc.nasa.gov/assets/img/latest/latest_4096_HMII.jpg

[JamesF]

A day without sunspots is uncommon at the moment, though sometimes they're few and small.

The Sun has a natural cycle of activity lasting around eleven years and we're considered to be near a maximum at the moment.  I've no idea what it's like near a minimum as I wasn't observing the Sun near the last one.

James

[LukeSkywatcher]

I havent had a chance to observe the sun since the last big AR went out of view. I check daily online just to see whats happening above the clouds. Not much to get excited about for the last month or so. My Hershel wedge is really paying off. 

LOL

[Sonicfishcake42]

You'll see sun spots regularly. Sometimes more, sometimes less, but there will always (well, nearly always) be something there to look at.

Two posts I await from you:

1. How do I 'find' the sun in my scope? Answer - there are many ways but a solar finder is best.

2. What's the best Herschel wedge? Answer - to be discussed.

Meantime, enjoy the light.

I've never veered into solar yet, my first thought would have been ''surely the sun is easy to find in the sky, it's perspectively more or less the same size as the full moon'' But in your question prompt I'm now thinking ''how the heck do I point the scope at it without being able to use my finder or look directly at it''... And come to think of it I've never tried to locate anything without my RDF! Perhaps I should have thought about that at the same time as ordering my filter !! 

Would a 40mm + 6.3 focal reducer do the trick? I'm guessing it will be very tricky?

Please forgive my solar naivety!

[LukeSkywatcher]

I've never veered into solar yet, my first thought would have been ''surely the sun is easy to find in the sky, it's perspectively more or less the same size as the full moon'' But in your question prompt I'm now thinking ''how the heck do I point the scope at it without being able to use my finder or look directly at it''... And come to think of it I've never tried to locate anything without my RDF! Perhaps I should have thought about that at the same time as ordering my filter !! 

Would a 40mm + 6.3 focal reducer do the trick? I'm guessing it will be very tricky?

Please forgive my solar naivety!

Finding the Sun is difficult because you cant look directly at it. The easiest way is to move your scope around (up/down/left/right) until the shadow of the scope tube is at its shortest on the ground and then you are pretty close. A bit of tweaking while looking through the scope with the filter should get you bang on target. A 25-30mm EP would be enough to find the Sun. It will give you a wide enough FOV. As for observing the Sun..........treat it like you would the Moon, and by this i ONLY mean use the same magnification. An 8-10mm EP is enough, but if you want to ramp it up a bit you can always use a 2x barlow.

We only have 1 set of eyes. Never ever take any risks or chances by looking at the Sun without the aid of safety filter(s).