hydrogen beta filter

[msh1]

hi all i got a set of narrowband imaging filters second hand the other week and there is a Hb filter what can i use it on nebula wise and also what colour should it be converted to

thanks

mark

[andrewluck]

The Hb emission line is at 486nm which is in the blue range of the spectrum.

Often used as a visual filter for the Horsehead and California nebulae.

Cheers

Andrew

[steppenwolf]

Hydrogen Beta (Hb) works well on the Rosette Nebula too.

[morimarty]

Strangely enough I was out last night imaging the rosette for the first time with a Hbeta filter. I'll look forward to processing this data to see what kind of impact it may have on the finished image. I'll just add it seemed good at rejecting moonlight?

[lensman57]

hi all i got a set of narrowband imaging filters second hand the other week and there is a Hb filter what can i use it on nebula wise and also what colour should it be converted to

thanks

mark

The NB filter will isolate the data corresponding to its pass band, what colour you wish it to be mapped to is up to you that is why you read " mapped to the Hubble palette, RGB or any other combination of the R,G an d B " . These colours are only the visual representation of the data and  some combinations are more aesthetically pleasing than others.

A.G

[msh1]

thanks all sorry for the late reply was out at xmas do last night 

mark

[glappkaeft]

With a mono camera there is no upside (except possibly if you you don't have a H-alpha filter) with a H-beta since the H-alpha is stronger. Visually the H-beta beats the alpha since our eyes are much more sensitive to that wavelength. I have been thinking that a H-beta (or possibly H-gamma) filter could be useful for unmodded DSLRs since they are well clear of the IR filter and the Bayer matrix has 50% blue pixels but I have not had the time to run the numbers.

[msh1]

i think what i was trying to ask is ha-o3-s2 = rgb so if i put hb in the mix what colour would i use i might be over thinking this tho 

mark

[lensman57]

i think what i was trying to ask is ha-o3-s2 = rgb so if i put hb in the mix what colour would i use i might be over thinking this tho 

mark

You can replace Oiii with Hb.

A.G

[msh1]

You can replace Oiii with Hb.

A.G

cheers lensman

[glappkaeft]

If you have a H-alpha filter I'd think twice about also using the H-beta. The images will be nearly identical although the hydrogen emissions of the H-beta will be weaker and the stars might be either weaker or stronger depending on colour of the star and the narrowness of the filters). You'd save a lot of time just assigning H-alpha to two colours. Another problem is that most H-beta filters are design for visual use in mind, not imaging.

[carl20171]

Depending on your software you may be able to link to a 4th color or reuse one of the RGB colors as a 4th and change the percentage. 

[lensman57]

If you have a H-alpha filter I'd think twice about also using the H-beta. The images will be nearly identical although the hydrogen emissions of the H-beta will be weaker and the stars might be either weaker or stronger depending on colour of the star and the narrowness of the filters). You'd save a lot of time just assigning H-alpha to two colours. Another problem is that most H-beta filters are design for visual use in mind, not imaging.

This is not correct I am afraid. The emission line  for Hb is ~452nm which places it firmly in the Blue region, Ha has a ~ 652nm emission line which is in  the Red end of the spectrum. The two images will be quite different. You maybe confusing this with Oiii that has an emission line of ~496 nm and is actually a Teal colour. There is a debate about having more benefit in using Hb on some targets rather than Oiii which is in fact quite weak with the same targets.

A.G

[msh1]

it looks like i need to experiment a bit ,if ha is dominant and o3 is weak use hb instead?? ,is there a list of dso that have strong hb, i know the rosette is , i probably wouldnt have bothered to put hb filter in the wheel to be honest but it was in with the other filters maybe take it out and not worry about it

[carl20171]

• This is from the Astronomic web site. 

 Hydrgon-Beta filters help backyard astronomers to see faint and elusive nebulas such as the Horsehead, California, and Cocoon Nebulas.

 

I did some looking and it seems there may not be enough objects to make a list of?

•  

Visual observation (dark skies): Very good, but only suitable for a few objects

Visual observation (urban skies): Unsuitable

Film photography: It depends, very long exposure time

CCD photography: Very good, but only suitable for a few objects

 

[glappkaeft]

This is not correct I am afraid. The emission line  for Hb is ~452nm which places it firmly in the Blue region, Ha has a ~ 652nm emission line which is in  the Red end of the spectrum. The two images will be quite different. You maybe confusing this with Oiii that has an emission line of ~496 nm and is actually a Teal colour. There is a debate about having more benefit in using Hb on some targets rather than Oiii which is in fact quite weak with the same targets.

 

A.G

I'm well aware that Ha and Hb have different colours. My point is that they are emitted from the same spectral series (the Balmer series). This means that Hb is going to be more or less identical to Ha except Hb will bearound 3 times fainter. For photographic use with a mono camera you'd be wasting a lot of time if you'd use Hb instead of or in addition to Ha.

[lensman57]

it looks like i need to experiment a bit ,if ha is dominant and o3 is weak use hb instead?? ,is there a list of dso that have strong hb, i know the rosette is , i probably wouldnt have bothered to put hb filter in the wheel to be honest but it was in with the other filters maybe take it out and not worry about it

Emission nebulae are rich in Ha, reflection nebulae are rich in Oiii as they are usually energised by a hot blue star nearby.

a.G