Nebula filters.

[paul schofield]

Hello again SGL, A bit of advice needed regarding nebula filters please. I have been looking at purchasing either a Sky Watcher. U.H.C or A Skywatcher OIII nebula filter for my scope, I have read reviews on both and it seams the UHC would probably be the better option. Just wondered if anyone has tried these filters ? I only have a SW 130P, so not expecting miracles. Which one would be better for reducing light polution ? any advice would be greatly appreciated, thanks in advance.

[Telrad]

I use a Baader Neo which seems to do the trick Paul

[crazyjedi]

Your scope doesn't have enough light grasp for an OIII filter. An 8 inch scope is the minimum aperture for using an OIII filter i'm told.

I have a Baader UHC-S filter which works well with my Skywatcher 150 so i can recommend a UHC from experience. I'd check the band pass of the filters you're considering before buying. If the band pass is too broad the visual effect may be minimal, however if the band pass is too narrow for your scope you may see nothing at all when you look through it.

Happy viewing

[John]

Your scope doesn't have enough light grasp for an OIII filter. An 8 inch scope is the minimum aperture for using an OIII filter i'm told....

I use an Astronomik O-111 with my 4" refractor and it works excellently. The Baader O-III's are not so good with smaller aperture scopes though and I agree that a UHC / UHC-S would more effective in the OP's scope.

Other good ones in smaller scopes are the Orion Ultrablock or the Telescope Services (TS) UHC, the latter is the same as the Skywatcher UHC I think.

Bear in mind that these really only benefit nebulae.

[bish]

I've got an Antares LPR which has worked well on my 6" scope. Never tried any others though.

[crazyjedi]

I use an Astronomik O-111 with my 4" refractor and it works excellently

Your 4 inch frac has more light grasp than a newt of the same aperture. The frac doesn't have the obstruction of the secondary mirror and it's associated mounts. That is why you are having success with an OIII filter. Frac's do have an advantage over newts of the same aperture size in this respect.

I was told on this forum that my 150 would struggle with OII filter when i posted a similar question some time ago. Also most web sites and shops recommend an 8 inch and larger scope for an OIII filter. (I reckon they're referring to Newts). I don't have any experience with an OIII filter on my scope but the overwhelming opinion seemed to be that a UHC would work better.

Happy viewing

[John]

I think it's actually because the Astronomik O-III has a more generous band pass width than other O-III's ( especially the Baader). That's why I bought it

Your 4 inch frac has more light grasp than a newt of the same aperture. The frac doesn't have the obstruction of the secondary mirror and it's associated mounts. That is why you are having success with an OIII filter. Frac's do have an advantage over newts of the same aperture size in this respect.

I was told on this forum that my 150 would struggle with OII filter when i posted a similar question some time ago. Also most web sites and shops recommend an 8 inch and larger scope for an OIII filter. (I reckon they're referring to Newts). I don't have any experience with an OIII filter on my scope but the overwhelming opinion seemed to be that a UHC would work better.

Happy viewing

[crazyjedi]

Yeah i went for my UHC-S because it's a little tighter than other UHCs but broader than the OIIIs. It always pays to check the Band width pass of the filter.

[paul schofield]

Thanks all for your advice, as usual greatly appreciated, I have a few other models to research now, mmm I spend more time these days trying to get more bang for my buck than stargazing, come on weather cheer up, thanks all, happy gazing.