Solar film fittings

[thunor]

Hi,

A couple of questions that I hope someone can help with?

I have an A4 sheet of the Badaar solar film, I was wondering, would it be better on an 8" scope or an 80ED?

Which then leads me to the second question.... Does anyone have a good tutorial to use on how to make a fitting for it. I know that it comes with instructions but normally people come up with better ways than originally designed?

Thanks very much

[Abernus]

I can't advise you one what it would be best to use it on as I have no experience with either. However I can confirm that the instructed method for making the fitting is excellent. I followed the instructions and it's as solid as a rock and fitls like a glove.

[simon955]

An A4 sheet might be pushing it, you will need enough sheet to cover the external diameter of the scope to ensure that no light can go past. A4 is only just larger then 8 inches. For my 6" i used 6 rings of 3mm mdf to sandwich the baader film in. Two were used to hold the film and 4 were used to secure it to the scope and cover the apature completely, its tightly fitted on so no risk of it falling off. Used contact adhesive to glue everything up. Might put up a pic or 2 when i get home.

[Mark at Beaufort]

Personally I would make the solar filter for your ED80 refractor. IMHO refractors are the best instruments for solar observing.

I have never made a DIY baader solar filter but if you follow the instructions I am sure it will be ok. I would suggest that it should be a close fit - making sure that the wind or someone cannot knock it off. Once complete make sure that there are no holes by looking through the filter at the sun with your naked eyes before placing it on the scope.

Mark

[Merlin66]

I made one for a C5 last year.

Use the heavy A4 card you get for binding reports etc.

Cut strips about 30mm wide and wrap them around the objective cell, gluing as you go; a layer of three strips was more than enough.

Held them is place with rubber bands until the glue went off.

Wrapped the ring with some Glad wrap (to stop glue getting to it)and then did a second ring on top of the first.

When dry the rings should fit snuggly on the end of the scope and one "slides" over the other.

Lay the Baader film over the inner ring and temporarily tape the edges down - don't pull the film tight.

Then slip the second ring over from the front and this will securely hold the film in place and give you a nice solid cell.

I have some images of the process...I'll find them and post them

[Psychobilly]

I made a partial aperture one for the CPC800...

Peter...

[Merlin66]

here are some images of the C5 Baader film retaining rings,

[thunor]

Thanks for your comments guys, great as always.

I'm going to have a go at it this weekend.

[RikM]

I made an off axis filter for my 150P.

I made edge rings exactly as Merlin66 described. And a pair of full aperture discs with 70mm offset holes. This was the biggest hole that would fit between the spider vanes. I left about 8 tabs sticking out from one of the discs. I taped a 90mm square of Baader film over the hole then sandwiched it between the discs, sticking them together with prit-stick. I trapped the tabs between the two rings like you would do with the film on a full aperture mask, and used masking tape to cover the seams.

This fits great and works really well.

In true cheapskate style I used an empty Shreddies box for the card. I have enough film left to make another 4 or 5 of these should it get damaged.

Rik

[LukeSkywatcher]

The next solar filter i have will be a ready made one. I have bought 3 sheets of solar filter in about 4 yrs. The 1st one i ruined due to not knowing my *** from my elbow about how to handle it with care. The 2nd sheet i actually managed to make a solar filter with that lasted about 3 yrs. I got rid of it because i just really didnt trust the integrity of it anymore because i left it on a shelf exposed to the air,dust etc and it fell off the shelf more times then i can remember so i thought it "better safe then sorry". The 3rd sheet i bought recently i stored in a drawer in a plastic bag. I recently took it out to use it and the whole thing had fallen to pieces.

I just am NOT very good with DIY and something that should take all of 10 mins to construct takes me the best part of 2 hrs.

I'm not really a solar observer though so i probably wont spent £70-80 on a ready made filter just on the off chance of maybe spotting a sunspot or two.