Solar Filter Help.

[Spacehead]

Hi All,

I have just bought a 8" solar sheet from amazon for my 200p - so I am wanting to make a filter.

When I look at the sheet, one side is glossy, whereas the other is matt.

Which side should face the Sun?

http://www.amazon.co.uk/gp/product/B00DS7S52W?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

Cheers

Mark

[Spacehead]

Sorry - also - I bought an 8x8 sheet - should have bought a 10x10 I think? So I may lose about 1cm all the way round bringing the "hole" through which the light can pass onto my 8 inch mirror to about 7" diameter.

Will this reduce the quality of what I can see etc?

Thanks again.

[Pig]

Mark,

There are two types of solar film, one for photography and one for visual. Please make sure you have the correct type before you use it for visual use.( the visual type is double sided and may not be different to look at)

I have not used one for quite some time so I am unable to tell you with any kind of confidence which side faces the sun.

As long as you get no light bleed the smaller size diameter will have no effect. Some folk even use off axis filters that are quite small in comparison to the objective.

[Spacehead]

Hi Pig,

Thanks for that - I have a few replies on the Amazon post I made - which sound positive for Solar Observing through a scope with this material.

http://www.amazon.co.uk/Hi-sheet-glossy-shiny-towards/forum/Fx2P982V2PVTK1G/TxMNJG60RXH3ZT/1/ref=cm_cd_dp_aar_al_a?_encoding=UTF8&asin=B00DS7S52W

I have read around and noted a few people have removed one of the caps on the scope cover - replacing it with solar film.  But I only see this on Dobsonian 200p - I have the Newt 200p

Could I do this "offset method" with my own scope cover - using the small hole?  (its about 2 inches I would think).

Ive made the filter now - as below.

It is sandwiched between two pieces of card and stuck fast to the lower one.  The ring of card holds the thing firmly in place around the tube - and I will be sticking that to the tube when observing.

No light leaks found on testing.  But am treating this very seriously.

[Pig]

Mark,

Using the small hole is what "off axis" is (not in the centre of the objective) and yes you can use this method on your newt.

A Dobsonian refers to the base only, most people use a Newtonian with this base, so yes is the answer again.

Your filter looks fine to me, a good tip when observing the sun is to only have the scope pointing at the sun when you are looking through it. Should you leave the scope at any point just point somewhere else as the heat can degrade what you see after a while.

Enjoy

Shaun

[Spacehead]

Cheers Shaun - much appreciated info.  Just need the clouds to go now - as usual :/

[Steve Ward]

Mark,

There are two types of solar film, one for photography and one for visual. Please make sure you have the correct type before you use it for visual use.( the visual type is double sided and may not be different to look at)

It's the superior Baader Solar film that comes in both Visual and Imaging forms not the poor quality polymer films.

Both types of Baader are double coated .

[Peter Drew]

Check whether the matt appearance on one side is not due to a thin protective layer that needs peeling off before use. 

[michael.h.f.wilkinson]

Check whether the matt appearance on one side is not due to a thin protective layer that needs peeling off before use. 

+1 for that. The prtective film looks slightly mat and should be peeled of

[Spacehead]

Nothing to peel off on the film - just a really really thin sheet.  I think its the cheapo one - didnt get the Baader - everywhere seems sold out.

Got a pic up now in the other thread

[bingevader]

I made an off set filter using the stopping down hole for my 8" dob for the eclipse and it worked very well.

However, if you've already made the nearly full aperture filter, I'd stick with that.

I noticed that the view through my etx90 (90mm aperture) was better than through the stopped down dob.

BTW, just for extra safety:

 and I will be sticking that to the tube when observing.

Yes, I'd do that too.