Glass Solar Filter or Solar Film

[Josh Wilson]

I want to get a solar filter for my 4.5" newt but I seem to have come to a fork in the road- Glass or Film? I have a glass solar filter for my 3.5" mak and it seems to give reasonably sharp and contrasted images of the sun. I have seen pictures of the sun from people that have used Baader solar film and they give a neutral gray color to the sun with more detail than what my glass filter seems to deliver. Has anyone used both Baader solar film and a glass white light filter and which would you say gives the most detail of the surface and sunspots?

[Merlin66]

I have and use various different glass solar filters as well as the baader solar film.

IMHO the Baader gives the best performance "bang per buck".

[DirkSteele]

I purchased a Thousand Oaks Optical glass solar filter for the Venus transit back in 2004 for my 11" SCT. At the time glass was more robust and generally higher quality. From what I have seen, other materials such as Baader solar film have rapidly caught up to offer virtually all the performance for less cost, so as Merlin66 wrote above, it is becoming far more difficult to justify the higher expense of a glass filter.

If you are looking for a positive of the glass, the precisely manufactured cell of the glass filter is less likely to fall off the scope than a homemade on utilising a material like Baader, but as long as you are careful it should not be much of an issue.

[Josh Wilson]

I purchased a Thousand Oaks Optical glass solar filter for the Venus transit back in 2004 for my 11" SCT. At the time glass was more robust and generally higher quality. From what I have seen, other materials such as Baader solar film have rapidly caught up to offer virtually all the performance for less cost, so as Merlin66 wrote above, it is becoming far more difficult to justify the higher expense of a glass filter.

If you are looking for a positive of the glass, the precisely manufactured cell of the glass filter is less likely to fall off the scope than a homemade on utilising a material like Baader, but as long as you are careful it should not be much of an issue.

The only thing I'm worried about is it getting caught by the wind if a big gust comes by and lift the filter off the telescope-- especially if I'm viewing. I hear Orion has released a line of solar film for their XT series, this looks alot cheaper but the reviews don't give much insight on what it's like exactly. Is there a major difference between Baader and Orion solar film?

[Merlin66]

Any solar filter, whether glass or the Baader film should be securely fastened to the scope so that it takes physical effort to remove! -not just a gust of wind.

[mdstuart]

If you are worried put masking tape on the telescope and then attach your filter with ducktape to the masking tape securely and it will take a tornado to get it off.

Mark

[LukeSkywatcher]

Forget a glass filter...................go for the solar film.

[johninderby]

Is there a major difference between Baader and Orion solar film?

Orion uses the Baader film in their solar film filters.

I think the Baader film is the next best thing to a Herschel wedge and does seem to perform better than the readily available glass filters.

John

[Steve Ward]

I've just made a couple of new filters using the film ,

Pop into your nearest Haberdashery and get an appropriately sized embroidery ring , they come in a variety if diameters from about 4" up to 21".

Sandwich the film loosely between the 2 parts and tighten the screw , you can then drill 3 holes in the ring and fit 3 x M3 bolts to clamp it to the tube.

I ran a small strip of flocking round the rim of the tube to prevent the screws marring the paintwork.

The rings cost around £ 2.75 each... !

[Josh Wilson]

If you are worried put masking tape on the telescope and then attach your filter with ducktape to the masking tape securely and it will take a tornado to get it off.

Mark

Here in AZ I don't think I have to worry about a tornado and you probably shouldn't observe the sun if a tornado happens to be sweeping through at the same time!!!

And those are some great pics, Steve. Ingenuity and creativity are your friends in astronomy.

Thanks for all the tips, guys, I plan on ordering my film as soon as I get a bit of money.

Clear skies and great observing, Josh

[Anweniel]

I have always wondered about film filters, the glass ones appear relatively expensive (when compared to film) but for an astronomical accessory not really all that expensive. Although the results posted in the galleries from those using them appear to show little issue, I find my intuition questions the quality of image with the inevitable folds and creases inherant in a home made solution. Are my instincts correct or does the non uniformity in surface texture of the film become irrelevant? Either way the glass ones look much more professional to my eye and appear to be sturdy (although fragile I assume!) and I have pondered getting one but is way down my list of priorities at the moment!

Forget a glass filter...................go for the solar film.

ok, but you give no support to your conviction?

[Merlin66]

What do you want to hear?

The Baader Film is very strong and excellent quality?

It is widely used around the world togive first class white light images?

What else do I say??

[johninderby]

One thing with the Baader film that can be difficult to get your head round at first is that being physically flat isn't important. In fact it's essential that the film be relaxed with no tension. So in this case a bit wrinkly is optically better than flat. The Baader film is surprisingly tough and durable.

The main problem with glass filters is that one as good as the Baader film would be prohibitively expensive. Zeiss made some that were just as good as the Baader film if not better but cost an arm and two legs.

So give me a Baader film filter over a cheap (£100.00 or £200.00) glass filter every time or actually a Baader Herschel wedge instead.

John

[Anweniel]

Thanks John thats what I was looking for, as I said I can see from posted pictures it seems optically to have no effect but it feels counter-intuitive to have a wrinkly filter lol. Its helpful to have experienced advice.

[mdstuart]

And remember to remove the clear film when you make up your filter with the Baader film!

Mark

[Moonshane]

I put a couple of loops of elasticated cord on my filter and loop these around my focuser. I'd have to really try to knock my (baader film) filter off.

[Josh Wilson]

I, too, have wondered if stretching out the Baader film might enhance the image quality but I heard that the film can rip if stretched too much. Definitely makes sense. But what is the science behind Baader film? And why is it better to have it loose instead of tightened up?

[sam mayo]

to keep my baader film on i keep my camping matt dew shield on my 250px put the cap on (altered with solar film over opening cap provided,tapped on securely ) then once in place i use four pins going through the matt protruding(the pins show about an inch on outside and inside of dewshield) to hold the cap in place,they are go through snug against the end cap,that coupled with the dew shield holding the cap in place it would take a miracle to move,can post pics if necessary,

i use knitting needles they are thick enough to be sturdy and not to big to be a hindrance.

thanks sam

[rwilkey]

For what it's worth, here's my set up with the standard baader ready-made filter - 114mm for my C100ED