Filters????

[qcdougn]

I've done a lot of reading recently of reviews for various visual filters for Light Pollution and Contrast enhancement. At times I'm almost convinced to get a CLS or Skyglow type filter. Then I read where they really don't help...??

The same is for the UHC filters for emission and planetary nebula... Sometimes they sound wonderful and then some reviews say they really don't help... I'm confused...filters are too $$$ expensive to buy and then sell at half price.

Help or advice on actual results attained in the field would be appreciated.

Thanks

Doug

[FLO]

The effectiveness of a Light Pollution Reduction filter depends on what type of light pollution you have, which is why reviews vary so much. Best check that your dealer will take it back should it prove ineffective.

The Baader UHCs filter is flippin marvellous on scopes with 4" or greater aperture, I wouldn't be without mine!

[qcdougn]

Steve,

Thanks for a good report on the baader UHC. I'm looking over the different manufactures of those...such as Orion UHC, Televue Bandmate, Lumicon, Astronomik...etc. I'll give baader a peek.

Doug

[MartinB]

Doug,

I have a UHCs filter and a CLS which I use with a 12" dob. My skies vary between Mag 4-5. The UHC is particularly effective with emission nebs, M42 is transformed with a significant enhancement of contrast and visible detail. Looking at M57 I have found the CLS filter slightly more impressive but both improve the contrast and blacken the sky compared with unfiltered.

Unless your LP is pretty light I think you would enjoy either of these filters

[John]

The effectiveness of a Light Pollution Reduction filter depends on what type of light pollution you have, which is why reviews vary so much. Best check that your dealer will take it back should it prove ineffective.

The Baader UHCs filter is flippin marvellous on scopes with 4" or greater aperture, I wouldn't be without mine!

Another vote for the Baader UHC-S here !.

I find it effective even with my 80mm scope. I have tried the Celestron LPRfilter and the Orion (USA) Skyglow filters as well and their impact seemed a lot less to my eyes.

John

[James]

I currently use several filters from Baader, the Neodymium, the UHC-S and the OIII. All three have their uses:

Neodymium: This tends to give me variable results depending which part of the sky I am looking at. In Taunton to my north all the streetlights are of the old yellow sodium type and the Neodymium is fairly effective at improving the contrast by removing light pollution. To my east is Taunton town centre with a wide variety of different streetlights including the more modern 'white' ones and I find the Neodymium to be less effective. Regardless of circumstances I've found the Neodymium to be helpful looking at Mars and Jupiter. Note that I'm using the older version of the Neodymium and haven't tried the newer one.

UHC-S: As with others this is my most used filter and one I wouldn't be without. It improves contrast markedly (very helpful when I'm in my back garden in town). It also doesn't take away too much light so I've been able to use it successfully on several scopes from 90mm upwards. Last July/August I was able to just leave it in the eyepiece as I trawled through objects in Sagittarius only a few degrees above my southern horizon. Its excellent for helping to improve the contract to pick out nebulae.

OIII: This is a little more 'specialist' in that it takes away a lot more light so isn't really suitable for smaller telescopes (less than 6"). Where the OIII excels is in certain nebulae for example the Veil nebula in Cygnus. Where the UHC-S helps and shows the Veil better the OIII leaves it starkly visible against a largely black background. This filter is one of those where you can be looking at an object and catch the merest glimmer of it then put on the filter and have the object jump out of the view. With this filter I've been able to use my neighbours 4" scope in Taunton (pop 55K with lots of lights) and see the Veil from my back garden (in fairness the view wasn't anywhere near as good as from a dark site).

If I had to pick only one it would be the UHC-S and I think its well worth having in your inventory...

James

[Eddie]

Best person to chat to about filters would be Bern @ Modern astronomy, there seems to be nothing that catches him out!

Eddie

[qcdougn]

Thanks to all for their valuable time and in-the-field experiences. From what several of you tell me, I should try a UHC-Baader filter and maybe as a second choice a O-III. I will order one of each.

My scope is a 11' SCT, so light reduction may not be too bad when using these.

I do have city lights to my East that provide a glow , not to mention nearby lights for many neighbors. For the house light issue I surround my scope with a light shield from plastic sheating along a metal framed-in area of (approx. 3m x 3m square).

Thanks again to all.. the cooperation from the SGL Group is fantastic. I may email Bern sometimes to get more in details later.

Cheers, Doug

[Andrew*]

Hi Doug,

you will not go wrong with a UHC-S or CLS for starters. Sometimes the UHC is better, sometimes the CLS, but overall I find I use the CLS more often as unlike the UHC-S I've found it to increase contrast better, and even on galaxies.

For certain objects, an OIII will also be very helpful, but as it's more specialist, wait until you try one of the above first.

Andrew

[FLO]

BTW, Tony (Whippy) has a number of these filters on loan for an SGL review, might be worth dropping him a PM.

[bern]

With an 11" scope you can afford the narrower bandpass of a conventional UHC filter like the Astronomik UHC vs the wider Baader UHC-S. It's possible then that you wouldn't miss an OIII filter.

bern

[Whippy]

BTW, Tony (Whippy) has a number of these filters on loan for an SGL review, might be worth dropping him a PM.

You could, but the review is on hold until the skies get dark at a sensible time! Plus I'm only doing a review on general light pollution filters, not narrowband filters like the UHC type. Unless Steve wants to send me some of those too... .

FWIW, for visual observations of emission and planetary nebulae, the UHC filter really does make a big difference. Well worth paying out for one. Just be aware though, that it really is just for nebulae. It won't work for Galaxies, Clusters etc etc

If you haven't seen it already, this site is a goodie: http://pages.sbcglobal.net/raycash/filters.htm .

HTH.

Tony..

[FLO]

.... I'm only doing a review on general light pollution filters, not narrowband filters like the UHC type. Unless Steve wants to send me some of those too... .

No probs, I'll send one Monday

Its only that I tend to think of the light pollution reduction effect of a UHCs filter as secondary to its main role - boosting the contrast of nebula.

[Whippy]

I agree enitrely Steve, and IMO that's where people can get confused.

Tony..

[GazOC]

A UHC-S is a nebula filter, anything else it does is a bonus, it also minimalises the effects of Moonglow but I wouldn't complain that it doesn't do that job well enough.

[Whippy]

Granted sir, but would you call it (and catagorise it) as a general light pollution filter?

Tony..

[GazOC]

No, I'm agreeing with you and Steve. Its a neb filter..

[Whippy]

You can tell it's Friday can't you....