Filter for seeing Nebulae

[Kain]

Ok, I'm now finally getting the hand of finding things, especially the fainter nebs like M76 (So proud about seeing that)

However I have read in a couple of books now that you need a filter to see the details in the nebs, and generally make them look better.

What filter do I need? I heard something about a HA filter, but I ain't clue what that is. I also wonder where I can get one as cheap as possible (I'm currently out of work)

Cheers

Kain

[russ]

I've never really used filters for visual. I had an Orion LPR filter once with my dob but never found it really did much. Although everyone raves about the OIII filters but it depends on what you want to look at.

Russ

[Kain]

Thinks like the Veil Nebula etc..

Kain

[MartinB]

The trouble with narrow band filters like Ha and OIII is that they cut out too much light. I think you can get some which are a bit broader which may help in light polluted skies. OIII may help on planetary nebs.

[daz]

Or something like the UHC-S - certainly made a difference on M42 for me last season. Haven't used it much this time round, cos I keep forgetting about it!! D'OH!

[John]

I have tried an Orion Broadband filter but it made no discernable difference through my scopes so I sold it. I believe that narrowband or OIII filters might be more effective but they also have the effect of dimming the stars (as MartinB points out) as well as increasing the contrast of the nebulae. Personally I think this is an area where I would "try before you buy" if possible.

John,

North Somerset

[Kain]

I have a LP filter that Arthur kindly gave me, might try that as I have been told certain LP filters work.

Sadly its going to down of rain for the rest of the week, so it might be a while before I get a chance.

Kain

[GazOC]

Light pollution issues aside, the narrowband filters work best, I've got an OIII and it def enhances detail on a lot of objects, I used to have a list.....I'l try a dig it out.

The UHC and OIII are proably the best to go for first, as they are usable on plenty of objects.

Daz,

I know what you mean about "forgetting"

[MartinB]

How narrow band is it Gaz. Is it the Astronomik one?

[Ambermile]

I have a LP filter that Arthur kindly gave me, might try that as I have been told certain LP filters work.

Sadly its going to down of rain for the rest of the week, so it might be a while before I get a chance.

Kain

That sodium filter is wicked on Jupiter oddly enough Kain - pity it's gone down now though Never tried the LP filter visually though tbh...

Arthur

[GazOC]

I've got the Baader (they were much cheaper) UHC and OIII. IIRC (and I may well be wrong, it was a while ago), the UHC can double up and be used on the same objects as a dedicated Hb filter as thats one of the lines it passes.

As Daz said the difference with M42 is pretty obvious even in a medoim sized scope, others like M57 are more subtle to the point of not being worth using the filter TBH.

[MartinB]

Ah! The Baader would be much better than the Astronomik for visual I think. The Astronomik ones are narrower and much better for imaging but cut out too much for visual

[GazOC]

Yep, the imaging ones are produced to tighter tolerences.

[GazOC]

Found it!! Objects/ best types of filter to use.

http://pages.sbcglobal.net/raycash/filters.htm

Very good resource, saves a lot of time finding out yourself.

[MartinB]

That's a great link Gaz. UHC it is then