Double stacked continuum filters

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Double stacked continuum filters

Post by Sol seeker uk »

Hi all, just had a look at purchasing a continuum filter for white light imaging as it's said to give slightly better contrast, when I see a double stacked version.. it gives a slight tilt to each other, anyone use one and can give abit of feedback? Are they any better than the single filter versions?
https://www.widescreen-centre.co.uk/baa ... -here.html


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marktownley
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Re: Double stacked continuum filters

Post by marktownley »

Don't waste the extra money on the double stacked version its a gimmick.


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Re: Double stacked continuum filters

Post by Sol seeker uk »

Thanks Mark, didn't know they existed until today


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Re: Double stacked continuum filters

Post by christian viladrich »

A continuum filter is a filter which isolates a small part of the solar spectrum where there is no strong spectral lines. So the name "continuum", meaning "constant" or "steady".
Accordingly, because there is no spectral line to be isolated, there is no need to have a very narrow band pass.

BTW, there are many "continuum" windows (and filters) : 668 nm, 555 nm, 450 nm, 432.2 nm, etc.

If we want to give a full answer to this, this is true that professionals use narrow "continuum" filters (in the range of 0.5 to 0.3 nm FWHM). This is because they want to sample spectral windows with no line at all.
This is not a concern or a benefit for the amateurs. 10 nm filters are OK for us.

So the recommendation of Mark :-)

BTW, deep sky Ha, OIII, Hbeta filters are quite usefull for solar imaging. Using this kind of filters reduces atmospheric dispersion and instrumental chromatic aberration (is any).


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Re: Double stacked continuum filters

Post by Sol seeker uk »

Thanks Christian for your detailed answer


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