Which ha filter ?

[Danjc]

It is to go with my asi183mm-pro when it arrives. 

As I will probably go with the Baader 1.25” LRGB set when funds replenish I was thinking the 1.25” Baader H-alpha 7nm. 

Cheers, Dan. 

Edited May 22, 2019 by Danjc

[Danjc]

I should add I have class 6 sky’s 

[DaveS]

How about the Baader 3.5 nm H alpha?

Narrower band generally gives better contrast, and is more moon proof.

Astrodons have become stupidly expensive, especially in the 3 nm band.

[tooth_dr]

Dan I have a Baader 7nm Ha filter and the rest Sii Oiii LRGB.  The Ha isn’t parafocal with the RGB so don’t feel tied to the same brand if that was your thinking. I also have an Optolong 7nm Ha filter and it performs well. 

[Danjc]

11 minutes ago, DaveS said:

How about the Baader 3.5 nm H alpha?

Narrower band generally gives better contrast, and is more moon proof.

Astrodons have become stupidly expensive, especially in the 3 nm band.

A little outside my current budget which is already smashed to bits !

5 minutes ago, tooth_dr said:

Dan I have a Baader 7nm Ha filter and the rest Sii Oiii LRGB.  The Ha isn’t parafocal with the RGB so don’t feel tied to the same brand if that was your thinking. I also have an Optolong 7nm Ha filter and it performs well. 

I was thinking that tbf, 

optolong seems within the same price range. 

[tooth_dr]

27 minutes ago, Danjc said:

A little outside my current budget which is already smashed to bits !

I was thinking that tbf, 

optolong seems within the same price range. 

I also have a set of 2” L Ha Oiii Sii filters by Optolong. I ‘think’ the Oiii is actually better with regards halos than the Baader. 

[Adam J]

Huum, I have seen many halos from optolong few from baader. The 7nm Ha is a well used and well liked filter. The main problem with optolong is that they do not have the same optical density of the baader filters. As such they allow much more out of band light to leak through than the baader or astrodon or astronomik filters. Here:

https://www.cloudynights.com/topic/602155-testing-optolong-and-baader-narrow-band-ha-sii-filter/

My personal view is unless you want to pay for astrodon or chroma filters you will see some sort of reflection in an oiii filter as it's the harder to produce AR coatings at green than near IR. Baader don't do as well as the premium filters but they do better than most in this respect. Also they are not the narrowest, but they are a quality product in there price range, no point in having a slightly narrower filter if it leaks out of band. I value good quality filters but if I had to sell my astrodon to get some cash I would replace them with baader filters. 

Also if you have baader lrgb then only baader ha will be close to being parafocal with your other filters. 

Adam

Edited May 22, 2019 by Adam J

[discardedastro]

I'd +1 the 7nm Baader, they're a great starting point and don't have major issues with halos/reflection in my limited experience.

Baader are a lovely midpoint in most things brand-wise - good enough to be effective and useful in almost all their products, even if they're not the best of the best, whereas others in the same price point often end up going for features or spec over functionality. I'd only look at Astrodon or other high high end brands once I had everything else in my system perfect, really - you'll get much better bang for your buck with a flattener, or mount improvements, etc - or accessories like dew heaters if you don't have those already.

[Benklerk]

I have the astronomik Ha 6nm filter. I have produced some great images with them.