which Filters?

[totalamateur]

I am having a hard time choosing viewing filters for my 127 Apo Triplet. Not for photography.

I have checked out a couple of links that were given by members of SGL concerning filters and what they do, but am still none the wiser as to what ones would suit best.

I will need a neutral density moon filter (Diacroic?) not sure.

Also a filter for viewing Nebula, planetary filter, color filters?

I would appreciate if someone can point me in the right direction with filters that would suit my scope.

[david o]

Hi Ray,

The only filter that is nearly indispensable is a Moon filter. A neutral density (Wratten No. 96) filter with ~13% transmission, from any of the known brands should do you (Orion Moon Filter). A variable polarizing filter (Orion Variable Polarizing Filter) is good for daytime/twilight viewing of the first/last quarter Moon.

The books Astronomy Hacks and The Backyard Astronomer's Guide, apart from being generally very useful, both cover choosing filters. To quickly resume them:

For deep sky (in order of usefulness) - narrowband (eg. Orion UltraBlock), O-III, H-β & broadband (eg. Orion Skyglow) filters.

For planetary - Wratten Nos. 15, 58, 80A & 25.

The effect of the filters is usually quite subtle.

Baader, Lumicon & Orion are all recommended brands.

HTH

And get 2" filters so that they can be used with all your EPs.

[totalamateur]

Hi Ray,

The only filter that is nearly indispensable is a Moon filter. A neutral density (Wratten No. 96) filter with ~13% transmission, from any of the known brands should do you (Orion Moon Filter). A variable polarizing filter (Orion Variable Polarizing Filter) is good for daytime/twilight viewing of the first/last quarter Moon.

The books Astronomy Hacks and The Backyard Astronomer's Guide, apart from being generally very useful, both cover choosing filters. To quickly resume them:

For deep sky (in order of usefulness) - narrowband (eg. Orion UltraBlock), O-III, H-β & broadband (eg. Orion Skyglow) filters.

For planetary - Wratten Nos. 15, 58, 80A & 25.

The effect of the filters is usually quite subtle.

Baader, Lumicon & Orion are all recommended brands.

HTH

And get 2" filters so that they can be used with all your EPs.

Thanks David, for your imput,

I will check out the one's that you have suggested.

I have been reading up on filters from different websites and also from the forum, and have been looking at the filters below Some of which have been recomended on snippets from the forum).

Would you recomend them????????? and is it best that i go for Dichroic?

I have also read that i have to be careful to choose one's that will suit my 127mm refractor because some filters work best on larger appetures

Baader Neutral Density Moon filter (plus variable as your sugestion)?

UHC-S Good all rounder for visual ????????

Baader Contrast filter or;

Baader Neodymium Moon & contrast filter (which one if any)??????

Color filters for solar system (Probably as you have suggested) although i have read that you can stack color filters as long as they are the lighter colors. What do you think, or have you any suggestions on that issue?

Lumicon Broadband UHC???????

I wish someone could just magic up a list and say "These are the one's that you need", To many choices.

[pvaz]

I could try to explain but someone else did it far better then I can:

http://stargazerslounge.com/primers-tutorials/84192-primer-understanding-choosing-filters-visual-use.html

http://stargazerslounge.com/primers-tutorials/38541-primer-planetary-filters-guide.html

[John]

Hi Ray,

You have had some great advice so far on this. I've tried a number of UHC and OIII filters and there are variations between the different brands which impact how the filter performs in a particular scope.

I've now settled on a equite expensive but excellent Astronomik OIII filter in the 2" size. For an OIII filter it's band pass width is reasonably generous which means that it's effective even with smaller aperture scopes (eg: my 4" ED refractor) as well as being great with my 10" newtonian. I find it has a significant impact on the contrast in nebulae, especially planetary nebulae. I've found it's effective enough to become a "single filter solution" for me.

[pvaz]

I wish someone could just magic up a list and say "These are the one's that you need", To many choices.

Only noticed this part now. This are the ones that you need (in my opinion of course):

- ND (Neutral density filter) for the moon.

And that's it!

I have color filters but I don't like the view, I prefer natural color on planets and moon even when detail is more subtle that way. I just observe for longer and get my eyes adapted.

I also have an OIII for nebulas, on the Veil Nebula and Rosette I noticed a great improvement. On most of the others I prefer the unfiltered view. It's useful but expensive, and I feel there's more to gain from better EPs, or even a bigger scope for DSOs, then to invest over 100£ on a piece of glass that improves only a couple of targets.

Ultimately nothing beats aperture + a dark sky.

[david o]

I wish someone could just magic up a list and say "These are the one's that you need", To many choices.

OK, this is just a synthesis from reading around on the web, but here goes. Listed in order of utility:

An ND Moon filter will have the most noticeable effect on your viewing (

Orion Moon Filter, 13% transmission

).

Next on your list should be a narrowband filter, to bring out nebulas & help reduce light pollution (

Baader UHC-S

).

Anything else really will give only very subtle results -

For pulling out the subtlest nebular detail then Lumicon O-III & H-β filters get good reports.

For planetary, Wratten Nos. 15, 58, 80A & 25.

HTH

[Moonshane]

I have a cheapo, unbranded light pollution filter which I have rarely used but inspired by Paul (lukeskywatcher) who found this far better on the moon than his 'moon filter' I tried it last night. much to my surprise, it really worked well and seemed to provide a more contrasty view with just as much reduced glare.

I was so impressed I am thinking of getting one of the Baader 2" versions and selling the one I have and forgetting the moon filters.

I have tried a few colour filters but hate the unnatural look they give.

my next serious filter will be either an Astronomik UHC or Oiii (again in 2") but I have other things to get first.

although I am sure your refractor is lovely, it's still 'only' a 5" aperture and therefore you might struggle to see detail on some DSOs.

[Chris H]

I agree with Paulo on this one but instead of a neutral density filter for lunar observing I use a polarizing filter other than that I prefer the views without but maybe I'm helped by having quite good skies.

I have a Skywatcher UHC filter but don't use it.

[John]

With some objects in smaller scopes a UHC or OIII filter is the difference between seeing something and not seeing anything. The Veil Nebula springs to mind here particularly. Without a filter I can barely see the brighest portion with my 4" refractor and thats because I know exacly where to look. With the OIII I can see both the Bridal Veil and Witches Broom sections and, on good nights, traces of Pickerings wisp as well - all in the same FoV with the 31mm Nagler - a lovely sight

[totalamateur]

My Thanks to;

David O,

Paulo,

John,

Shane,

Chris.

for all your help and advice.

The links that you gave me were Excellent.

It has been so usefull that I have finaly made a decision.

As follows;

2" Variable Polarising filter (Baader - Orion -Lumicon, (not yet sure)

2" Baader UHC-S

2" Wrattan 15,25,58,80A (Not sure about make yet)

2" Astronomik O111

I will see how I get on with them, before rushing out to buy the whole shop, as I usually end up doing.

[great_bear]

Some nice choices there Ray.

Like others here though, I'd really, really hold off buying those coloured ones. I think that any improvement is just glare reduction, that's all. Just my opinion. I do have a set - but I think they're a waste of money.

- and if you're buying a variable polarising filter (at least I assume it's a variable one you're after?) - then you've already got the attenuation needed to tame the glare of the brighter planets, and I doubt that those colour filters will offer you anything useful.

In terms of colour filters, there are only two that I have found useful so far - and both are for lunar observation:

1) #29 Dark Red (a great tip from BrianB) - This is the filter to use if you want a brief look at the moon without the "punched-in-the-eye" feeling and - more-importantly - to protect against loss of dark-adaptation. It also offers the great benefit of allowing you to look at the moon with considerably more magnification than would normally be possible when the seeing conditions are less than ideal.

2) #8 Light Yellow. When you don't particular need to protect yourself from the glare of the moon, this filter can prove useful. To my eyes there's something a bit peculiar about the unfiltered Lunar Maria inasmuch as - despite being darker - they seem to dazzle in a strangely-disconcerting, beyond-visible manner (like those nightclub UV lights). The #8 Light Yellow filter (which is very subtle) seems to tame this glare and makes the lunar image more 'normal' to my eyes. Note that this is purely a personal observation and I've not heard anyone else mention the same phenomenon.

- hope that's helpful.

[nicnac]

I have the baader neodymium filter and i have just sent off for a variable polarizing moon filter from FIRST LIGHT OPTICS and thats all i plan to get.

anything other than these, for me, would be a waste.

[Chris H]

With some objects in smaller scopes a UHC or OIII filter is the difference between seeing something and not seeing anything. The Veil Nebula springs to mind here particularly. Without a filter I can barely see the brighest portion with my 4" refractor and thats because I know exacly where to look. With the OIII I can see both the Bridal Veil and Witches Broom sections and, on good nights, traces of Pickerings wisp as well - all in the same FoV with the 31mm Nagler - a lovely sight

I have tried the Skywatcher OIII and UHC filters (ordered the UHC from FLO but the OIII was sent to me by mistake, anyway Steve said whilst I was waiting for the UHC to try the OIII) I was not really impressed by the views through either really maybe I should try a Lumicon or Thousand Oaks and see how I get on.

[great_bear]

For OIII-style filters, you need to be looking at the right kind of object (emission nebulae) and have eyes that have been very well dark-adapted.

The view of the Great Nebula in Orion through my Ultrablock whilst in Bideford last year was a truly memorable experience. Much fine detail could be seen.

[John]

I have tried the Skywatcher OIII and UHC filters (ordered the UHC from FLO but the OIII was sent to me by mistake, anyway Steve said whilst I was waiting for the UHC to try the OIII) I was not really impressed by the views through either really maybe I should try a Lumicon or Thousand Oaks and see how I get on.

Filters are not everybody's "cup of tea" - on most DSO's I prefer the unfiltered views. There are also variations in band pass and, I suspect, optical quality between brands which do have an impact on the views.

Lumicon do seem to get consistently positive mentions in the forums I frequent, which can't be a co-incidence.

[pvaz]

i'm with Chris and John on this. I got the Baader OIII, thought about selling it but then I'd loose money and what I'd get from it doesn't seam much so I'm going to keep it.

Is it worth the 100£ or so? I don't think so. I like to see the veil and rosette through it, but it always seams to dim the view too much. On any other nebula I tried it on (M42, M57, M27, M1, M97, Pleiades, Cat's Eye, Blue Snowball, Cleopatra and at least 10 more I can't recall) I didn't see a great improvement, sometimes it even get's worst, as in M42 where structure detail suffers a lot, although the nebula seams a bit wider.

I read the same about lumicon filters, so there must be a reason why they cost almost twice the value. I'm certainly not investing on other filters of this kind when I know a 12", 14" or 16" dob will improve the views much more then any filter. They do cost more when compared to the filters, but the aperture will help on almost every object while the filter is limited to 100 objects or so (being very optimistic here).

[great_bear]

Lumicon filters are made from Schott and Hoya glass.

The cheapest "unbranded" filters aren't even optical grade glass.

Lumicon also claim that both sides of their filters are coated (so I'd like to know why - on all my Lumicon filters - the reflections off one side look totally different to the other then! It looks to me like there's only one side coated!)

[totalamateur]

I have a cheapo, unbranded light pollution filter which I have rarely used but inspired by Paul (lukeskywatcher) who found this far better on the moon than his 'moon filter' I tried it last night. much to my surprise, it really worked well and seemed to provide a more contrasty view with just as much reduced glare.

I was so impressed I am thinking of getting one of the Baader 2" versions and selling the one I have and forgetting the moon filters.

I have tried a few colour filters but hate the unnatural look they give.

my next serious filter will be either an Astronomik UHC or Oiii (again in 2") but I have other things to get first.

although I am sure your refractor is lovely, it's still 'only' a 5" aperture and therefore you might struggle to see detail on some DSOs.

Thanks Shane,

You'r correct about the 127mm being small, but bare in mind that I will be viewing from a mountain top in inland Spain where there is little or no light polution. Also, I have to bare in mind that I will be purchasing a 24" reflector a bit further down the line. So I am attempting to make choices that will suit my present setup as well as my future one.

[John]

...I will be purchasing a 24" reflector a bit further down the line. So I am attempting to make choices that will suit my present setup as well as my future one.

In which case you will probably want to leave enough in the budget to swap your 2" SWAN's for UWAN's or similar. The SWAN's don't do so well in fast scopes.

[totalamateur]

I have tried the Skywatcher OIII and UHC filters (ordered the UHC from FLO but the OIII was sent to me by mistake, anyway Steve said whilst I was waiting for the UHC to try the OIII) I was not really impressed by the views through either really maybe I should try a Lumicon or Thousand Oaks and see how I get on.

Hi All,

Opinions seem to vary quite a lot, which has again confused me.

It seem that the following have possitive comments;

Variable ND polarised moon filter.

UHC-S filter.

It seem that the following have mixed comments;

The O111 seems to only be effective on 2 nebula.

The color filters seem to only offer subtle differences.

More feedback required please

[totalamateur]

In which case you will probably want to leave enough in the budget to swap your 2" SWAN's for UWAN's or similar. The SWAN's don't do so well in fast scopes.

Actualy John,

I have seriously been looking at the Televue Ethos & Pentax XW ranges, which seem to have excellent reviews. Expensive I know, but what the hell, I can always sell the car

[pvaz]

The Baader OIII on my 8" only provides a great improvement on 2 nebulas (so far). It's effective on the others too, it's just that I don't like the "effect" which usually darkens the star field around too much, makes the nebula dimmer and fuzzier but more defined in relation to the background (cause it's dimmed way more then the nebula) and adds a green tint to everything, including stars.

That doesn't necessarily means you'll have the same experience with other filters on that scope, or the same filter on another scope. This are very subjective things.

This is a very extensive test of all nebula filters and observable results on different scopes:

The Prairie Astronomer

[totalamateur]

The Baader OIII on my 8" only provides a great improvement on 2 nebulas (so far). It's effective on the others too, it's just that I don't like the "effect" which usually darkens the star field around too much, makes the nebula dimmer and fuzzier but more defined in relation to the background (cause it's dimmed way more then the nebula) and adds a green tint to everything, including stars.

That doesn't necessarily means you'll have the same experience with other filters on that scope, or the same filter on another scope. This are very subjective things.

This is a very extensive test of all nebula filters and observable results on different scopes:

The Prairie Astronomer

The subject of filters seems to be extremely complicated for a newby like myself. I have just been reading about bandwidths on the ASTRODON site (see link below), and am still none the wiser.

I have read the Prairy astronomer report on various filters but they were tested through a 10 inch f/5.6 reflector, so I am not sure how they will perform through my 5 inch f/7.5 refractor?.

Astrodon Astronomy Filters - Narrowband Filters

The Prairie Astronomer

From what I have gathered so far, it seems that the way to go is; Purchase some very expensive filters, try them out, and if you don't get on with them, sell them at a great loss to someone else who can suffer the same process.

[pvaz]

It's not that hard.

1) light haves different colours

2) each colour haves a wave lenght (it behaves like a wave on the water)

3) a narrow-band filter (such as OIII or UHC) only lets some very specific wavelengths come through and blocks all the others, that's why when you hold one in day light it looks like a mirror, cause it's blocking almost all the light.

4) What wavelength do the filters let through? Specific wavelength (or colours if you like) that are reflected by the material that constitutes the nebula. Thus it makes everything dark and let most of the nebula light through. since not all nebulas are made of the same material, different specific filters for each type is needed.

That article link I posted last, haves real tests of different filters on different targets. With that info you don't need any knowledge on wavelenghts and how filters work. Just pick the filters with the highest score for the target you wish and see how you get along with it.

PS-> They say in the introduction they used all of this scopes: 10 inch f/5.6 Newtonian (52x, 71x, 104x, and 141x), 9.25 inch f/10 SCT (59x, 98x), 8 inch f/5 Newtonian (32x), 100mm f/6 refractor (15x, 22x) (this one is smaller then yours).