Solar film....which one?

[russ]

I need to make a new white light solar filter for the refractor. Was going to go the usual route of Baader Solar film but remembered the lovely yellow view i used to get with my Thousand Oaks glass filter. Anyhow, while browsing the Rother Vally Website i noticed they do Thousand Oaks Black Polymer Sheet which gives the same colour result as their glass filters.

Anyone used the Black Polymer Sheet?

I found a very short thread on CN and there was one comment that suggested the Black Polymer was better visually but the Baader better for imaging. As a non imager, that would suit me. But that guy said it was only rumour.

Russ

[brianb]

Baader solar film is wonderful, if you want a yellow/orange tinted view just add an ordinary deep yellow / orange filter.

I haven't used the "black polymer" filters but suspect that they would have to be very flat optically if they're not going to degrade the image at high magnifications (most glass filters do!) and I doubt they're that good at the price charged. Probably fine for SLR imaging of eclipses with shortish telephoto camera lenses though.

[russ]

Thanks Brian, that's made up my mind to order the Baader sheet as usual. Many thanks.

[johninderby]

I bought some of the Thousand Oaks black film and compared it side by side with the Baader film last year. Result......took the Thousand Oaks film, screwed it up into a ball, and tossed it into the bin. The Baader was just so much clearer with more detail, and as mentioned before a coloured filter gives a yellow sun if you want.

John

[John]

A timely thread for me, this one (thanks Russ !). I'd like to make a white light solar filter for my 6" refractor. I saw some of the 1000 Oaks film on e.bay a few days ago but it was a LOT more £'s than the Baader film. Looks like the Baader is the one to go for.

[Macavity]

I have a Thousand Oaks GLASS filter for my MAK 127 and some Black Polymer sheet from RVO. The transmission of the latter seems distinctly less than the former - Visually, the image is a fair bit dimmer? I'm just about to try the Baader film. I sense, if you want to use e.g. the (greenish!) Baader solar continuum filter, the wider spectral bandwidth (i.e. blue-white image) of their film might allow a little more flexibility. Though even "orange" filters seem to transmit quite a bit of green/blue... even (achromat!) violet.

I sense sometimes filter materials emerge fortuitously, and the publicity is developed retrospectively. <G> Intrigues me too what "Particle Physicists" (allegedly) use some of this stuff for... But we used to use a lot of reflective MYLAR to hand wrap scintillator detectors - ACRES of the bloomin' stuff!

[Macavity]

Here's some (about the only!) data on solar filter characteristics.

http://eclipse.gsfc.nasa.gov/image/filter.gif

(From: NASA - Eye Safety During Solar Eclipses)

I suppose it explains why some T.O. glass filters are orange? <G> I believe they are chromium on glass - Perhaps one would indeed expect a smooth absorption spectrum? The various others (some unsafe!) are certainly (predictably?) more spikey...

[LukeSkywatcher]

I also was recently looking to buy more solar filter film and i saw the "Thousand Oaks Black Polymer Sheet which gives the same colour result as their glass filters".

I didnt buy it because i could not get my head around how it is possible to observe the sun through a black polymer.

So i nce again went with the standard Baader solar film.

Yes it shows white light...............but as Brian says.....................all you have to do to change that is use a standard coloured filter. Yellow works great as does orange. If you are feeling adventurous you can even use blue or purple. Infact any colour filter i have used works well. Whitelight can still be dazzling and the coloured filters just make observing a bit more comfortable.

[LukeSkywatcher]

I bought some of the Thousand Oaks black film and compared it side by side with the Baader film last year. Result......took the Thousand Oaks film, screwed it up into a ball, and tossed it into the bin. The Baader was just so much clearer with more detail, and as mentioned before a coloured filter gives a yellow sun if you want.

John

Enough said.

Baader wins every time hands down forsolar observing on a budget.