Baader film

[george7378]

Hi everyone,

I'm going to buy some Baader solar film from First Light Optics - just to be sure - I don't need to buy anything to go with it? I don't need to buy a filter frame?

If possible, could you tell me about your experiences with this product?

Thanks!

[LukeSkywatcher]

Hi george. The solar film is great stuff. You will be able to make a filter holder for it using a couple of strips of cardboard and stickytape. You get nice views of the Sun in whitelight with it. You will also be able to observe sunspots through it.

[Dave Smith]

Agree with Paul. You need to make your own frame with cardboard. Do make sure that it is secure and cannot fall off. Also it is important that the film is not stretched, it should be quite loose and does not matter if slightly wavy.

Dave

[yeti monster]

Place the film between 2 sheets of cartidge paper whilst cutting it. This ensures a clean shear of the film and also helps to keep them grubby fingerprints off it, the acidic nature of which, will etch into the film and weaken it.

Make two hoops of stiff card to sandwhich the film between (my film came with a cellophane layer, which I put to the outside, as a means of protecting it from contamination). Apply a layer of adhesive to one side of each card ring and between the outer edges of the film and cellophane layers, to keep everything together in the event of a sudden breeze. If you have latex/nitrile gloves use them, they make handling the film safer.

Allways inspect the filter prior to each use, if in doubt, chuck it out!

Keep your filter in a ridgid container and explain the obvious to anyone who is likely to use it.

I've made quite a few of these filters now, and only had to bin one after not explaining its delicate nature to a collegue, who crumpled it. Upon inspection it then had a tiny pin hole in it, so out it went, meaning that I had to resort to solar projection!

Up til now I've not used the adhesive method (other than a practice build on the already damaged filter), relying instead, on "stitching" the assembly together with small bits of duct tape. However, I am sure that at some point the film will come adrift with disaterous results, so from now on I'll be glueing them in.

[johninderby]

Here's an illustrated guide to making the filter cell that should help.

http://www.agenaastro.com/v/vspfiles/assets/images/agena_files/making_a_solar_filter.pdf

John

[george7378]

Thanks! With my 130mm scope, I can make 2 filters, plus maybe two small ones for my binoculars, and one for my finder.

[SkyHermit]

It's good stuff, just look out for that cellophane layer. Didn't realise it was on there until after I had made and taped up a nice cardboard frame.

[Merlin66]

Yeti,

I've yet to see a pin hole in any of my solar film filters... but they can be "fixed" by spotting the pinhole with tipex/ white out correcting fluid. I've done this to a couple of others (generally as a result, as you say, of gross mishandling of the sheet)

Ken

[LukeSkywatcher]

Also it has been said elsewhere that if you have and use a green coloured filter with the solar film that it brings out the contrast more and you can see the granulation of the suns surface. I havent tried this yet myself.

[Leegsi]

Also it has been said elsewhere that if you have and use a green coloured filter with the solar film that it brings out the contrast more and you can see the granulation of the suns surface. I havent tried this yet myself.

So with a green filter and my SW150 with the film I should see the 'orange peel' effect?

[Merlin66]

Yes, with sufficient magnification (> x100) and steady seeing.

[Merlin66]

Yeti,

Quote:(my film came with a cellophane layer, which I put to the outside, as a means of protecting it from contamination).

I wouldn't retain the "cover film" - not required and adds another layer of complexity.

The Baader film just needs an occasional blow down to keep it as new.

Ken

[LukeSkywatcher]

My filter is covered in a layer of dust that will not come off. Its pretty caked on there. It doesnt seem to hamper the performance of it. I check for holes,tears etc and none to be found.

I have a sheet of solar film unopened. I bought it a few weeks ago. I'll get around to making a new filter soon and one for my camera. Not too sure how to do one for the camera as the zoom ring and focus ring need to be available to me. I guess just a simple square card with the film sandwhiched between and affixed to the very front of lens with something like blu-tac or something (similar to a Coken filter). Safety isnt as much of an issue with the camera as it is with a scope. Looking at the sun on the camera LCD isnt going to blind you for life although it will give you spots infront of your eyes.

[Peter Drew]

I can also vouch for the effectiveness of the Baader film and have made several filters over the years. The thing that is puzzeling me is the reference to the visibility of the solar granulation. I used to believe that this was difficult to see in white light with apertures much less than 5". However, I have a binocular telescope I built from two 4" F5 Startravel scopes, I made filters for the 2"apertures revealed by the removeable caps from the main objective cover and the granulation is easy to see on a good day with a mag of 25x

[Moonshane]

I was always worried about the safety of these but maybe I should have a go.

I will be interesting to see the sun through the scope. My refractor cap has a small (approx 50-60mm) cap in the middle. would it be worth buying a small ready made filter for this? that way I could drill holes in the 'side walls' of the cap retainer and the screws for the cap could just bed into the holes making it 'belt and braces' safe.

edit - ha ha like Peter says above!

[LukeSkywatcher]

Shane the only safety issue with the solar film is if you have made a good strong casing to hold it so that it will not come off. The film is said to stop 99.999% of the harmful light and heat. It really is safe as houses (how safe is a house?).

The removable cap in the middle of your scopes dust cap is there for exactly the reasons of solar observing. It stops down the apeture to about 50%. You could fix a bit of solar film to the inside of dustcap (SECURELY) and observe that way. I cant stress enough how securely the solar film would have to be inside the dustcap.

I have yet to see a single sunspot with my 90EQ (i now use this as my dedicated solar scope). Its fun observing though and tyring to find them.

[simon84]

I'm going to be getting some of this Baader film soon. Looks like alot of fun. I'll be using my Equinox 80ED. I was quite lucky and found a cheap filter holder on the astroboot with 3 securing screws on the outside so all I need to do is pop it over the dew shield and screw it up nice and tight.

As for putting the film into the holder I'm going to use Yeti's method and make two circles and fix it all together with aircraft tape (really strong stuff, used it for sticking stainless steel covers to plate glass) and then stick it into the holder.

I'll get some pics together when I do it.

[george7378]

It's on its way! I can't wait to see the Sun through it.

[simon84]

I ordered mine today aswell, now we've done that it'll be raining for months......

[yeti monster]

Yeti,

I've yet to see a pin hole in any of my solar film filters... but they can be "fixed" by spotting the pinhole with tipex/ white out correcting fluid. I've done this to a couple of others (generally as a result, as you say, of gross mishandling of the sheet)

Ken

I did try this sort of repair, but still felt that it was a tad risky, also, after I'd had a trial at glueing the edges down, I saw that I'd put a finger print onto the film, which I know isn't good for such things. thus I decided to bin that one. I'll make a shiney new one when I get home.

[LukeSkywatcher]

This stuff is so robust that i would almost place a full sheet of it over my scope objective and tie it down with an elastic band.

[george7378]

I've made my first Baader filter, and sneaked a naked-eye look at the Sun through it - it looks amazing! I really can't wait to see the Sun tomorrow! I'm on the way to becoming a Solaholic!