Chroma 3nm or stick with baader

[Steve 1962]

I started off with Baader NB filters and had halos around bright stars. When I put this to the vendor, he replaced the filters....and I still suffered halos. A bit of research found that this is a common problem with the Baader filters.

I later replaced my whole filter set with Chroma filters (LRGB and 3nm Ha, Oiii and Sii) from Modern Astronomy - and the improvement was dramatic.

Here's Baader Ha of Alnatak

..and here's Chroma Ha 3nm

 

No halos, stars is smaller and the background is darker.

Also - here's a comparison post from just after my Chroma purchase: 

I use my Chroma's at f3.6 and when I bought them, they were optimised by Chroma for the f3.6 beam - I don't know if they still do this.

Bottom line - I've been delighted with my Chromas and would wholeheartedly recommend them

WTH

Steve

 

[HAlfie]

Hello Ken,

I've been there. Last year I used Baader LRGB-SHO filterset and since a few months, I've decided to jump into Astrodon LRGBSHO 3nm filterset (in second hand). Chroma are clones of Astrodon so don't worry about it. The baader filters are the best bang for the buck in narrowband but once you want to step up a little, Astrodons/Chromas are the best out there (narrowband).

Indeed, the 5nm Chroma costs the same as 3nm, it's no mistake, it's the same ridiculous price difference in the US. That's why 3nm are a better choice for Chromas, especially compared to Astrodons 3nm prices!

The Chroma & Astrodons have a real transmission of at least 90% guarantee, when the Baader can vary from 75% to something like 90% in the reality.

Having used the Astrodons for a few months, the difference is significant over the Baader (I mean thank God for a 3 x narrower filters!). With narrower filters, you'll increase the time available to take deep sky picture as even with presence of the moon,  the 3nm Ha is almost bulletproof! You just have to avoid to have a full moon really close to the object you're aiming at.
Now let's talk about the 3nm OIII, the difference is important as I had almost no halo with the Astrodon when the Baader had some halo on bright stars. Adding to that, the 3nm is almost 3 times narrower than Baader OIII 8,5nm. Stars are tighter, and you the 3nm is more resistant to the presence of the moon. Though, using OIII during moon phase isn't always the best idea as it is the one the most affecter by it. I think you can reasonably use the OII until 50% moon phase and with an object, at least 50° away from the moon.

I've compared the 5nm & 3nm astrodon filter on a same night/same object. The 5nm gives the same signal/noise ratio (as the 5nm has NII line in it) but, the stars are slightly smaller than with the 3nm.

A good combination would be 5nm Ha, 3nm OII & SII but as chroma narrowband filters have the same price betwee, 5nm & 3nm version, don't hesitate to go for 3nm 😁.