narrowband filters stacking

[Fieldsy]

Hi all I was just reading a few filter reviews and they talk about stacking 🤔 so does this mean you can stack Ha,Oiii,Sii together and get 15hrs data for 5hrs time ?

Thanks

[Adam J]

44 minutes ago, Fieldsy said:

Hi all I was just reading a few filter reviews and they talk about stacking 🤔 so does this mean you can stack Ha,Oiii,Sii together and get 15hrs data for 5hrs time ?

Thanks

No it wont work like that, one filter will block the other and vice versa. Got to use them one at a time. I have no idea why anyone would want to stack filters for imaging.

[Demonperformer]

As above, that doesn't work - but I do like the way you are thinking!

But (if you haven't already got your filters) you can get filters that let through multiple wavelengths. I have a duo filter (Ha & Oiii) that is used with a colour camera and catches Ha on the red channel and Oiii on the other two [it's a bit more complicated than that, but that is basically it], so i can separate out the two signals and they can be recombined with a third filter/colour (I use NeIII). There are also a couple of (so-called!) triple band filters that simply widen one of the bandwidths to let through either Hb with the Oiii signal or Sii with the Ha, so it is not possible to separate them out.

Edited October 1, 2019 by Demonperformer

[teoria_del_big_bang]

Maybe the filters they were talking about were for DSLR cameras as these are often stacked to create certain effects as indeed the mounted ones will screw into each other but not sure it would have any practical use in RGB or NB for astronomy, in fact you probably would just block everything getting to the sensor.

People often put a light pollution filter of some sort in the train as well as a RGB or NB filter but it is hardly stacking as they are not exactly screwed together.

Steve

[Louis D]

No, stacking narrowband filter won't work as others above have pointed out.  However, OPT is selling Radian Triad tri and quad band filters that simultaneously transmit H-alpha, H-Beta, and Oxygen III or H-alpha, H-beta, OIII, and SII respectively.  They would achieve what you want to do.  Keep in mind that you would need to use a color camera to retain color data.  A monochrome camera would show all bands as various shades of gray in a single image that would be immune to post processing into a color image.