Narrowband Imaging

[dazza1639]

I am just about to treat myself (christmas & last years birthday money) to a narrowband filter set. I've got a couple of questions that maybe someone could help with.

1, Do I need my light pollution filter in front of my focal reducer when using narrowband filters in the filter wheel?

2, I can currently get a baader filter set with Ha, Oiii & Sii for an extra £20 I can get the set with H beta included. Is the inclusion of Hb useful or would it just sit in the wheel and not get much use?

3, Are the baader filters any good? I have the lrgb set and love it.

Thanks

Darren

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Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[swag72]

Regarding the LP filter, I think you can realistically do what is going to fit in best with you. I don't have one in the imaging train all of the time, but I do know of folks that do. It won't stop that much signal getting through! 

The Baader NB ones are good, I think that most of us have probably started off with them. Regarding Hb.... I did wonder about that myself a couple of years back, but looking around and asking some questions led me not to bother. There's so few targets where there's any Hb and people said that you can easily get an Hb equivalent by combining a percentage of Ha and OIII I think it was. Not sure what those percentages were. I've certainly never though 'Oh damn, I really need an Hb filter' - so personally I'd not bother.

NB imaging is great!!! So much easier than LRGB I think!!!

[dazza1639]

Thanks looks like I'll save a bit of money. Good to hear that the baaders perform well

Darren

------------------------------------------------

Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[dazza1639]

Would the astronomik emission line filter set with the 12nm Halpha be a better bet than the baader set as it is not much more expensive

Thanks

Darren

------------------------------------------------

Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[DaveS]

I bought a H-beta filter with the intention of doing H-alpha, [OIII], H-beta imaging of M42 (Among others) but never got round to putting it in the wheel. I think I'd go with the Baader filters rather than Astronomik as they're parfocal with each other and with the LRGB set, assuming your 'scope is well corrected.

The choice for me was between Baader and the head-bangingly expensive Astrodons.

[dazza1639]

It looks like the baaders are a winner

Darren

------------------------------------------------

Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[ollypenrice]

Hb usually traces the same gasses as Ha but with far less signal. This means you can give the blue channel a whiff of Ha as a false Hb if you like, though I rarely do.

The Baaders are good though the O111 is probably the weakest with a tendency to give halo artefacts sometimes. If stopping short of the Astrodons I'd go for Baader.

Olly

[dazza1639]

Baaders on the way I didn't bother with the Hb

Darren

------------------------------------------------

Twitter: @SalAstroSoc @Astronut1639 www.salfordastro.org.uk

Nexstar 8 GPS ADM MDS Rings & Counter Weights, Skywatcher ST80 & Synguider, Canon EOS 1000d,

Dew Heaters & 4 Channel Controller, Orbit Wedge, Observatory and not enough clear nights

[nucdoc]

As far as I understand, Narrow band filters pretty much eliminate light pollution, as most light pollution does not emit in the Narrow band imaged with Ha, OII filters