A suitable filter for observing nebulae

[lensman57]

Hi,

I have a SW 127 SynScan az scope and on the rare occassion that weather and seeing permit I would like to observe some of the brighter nebulae around Orion, what type of filter if any is suitable for this size scope please? I have rulled out the Oiii filter as it will not suit the scope but would a UHC be a better option?

Many thanks,

A.G

[John]

A UHC would be a better option I think. They are a bit more versatile than O-III filters, especially in smaller aperture scopes. The Skywatcher filters seem to be OK and are not too expensive. Some nebulae will benefit more than others and these filters do dim the stars a bit but that allows the contrast of the nebulae to stand out a bit more. Personally I prefer unfiltered views of the brighter nebulae like M42, M57 etc but a UHC filter (and an O-III filter in larger scopes) makes some objects, such as the Veil and Owl nebulae, actually visible when without a filter they practically disappear.

[Moonshane]

on the whole for your scope I'd agree with John.

my recommendation if you have a 2" focuser is for 2" filters but I think yours is a 1.25" only focuser?

[acey]

Only filter I have (and only one I've ever felt the need of) is a Lumicon UHC, which is excellent. The "brighter nebulae around Orion" would not all benefit from a filter: M78 is a reflection nebula so a filter will only make it fainter. But for emission nebulae a filter can certainly make a difference.

[Double Kick Drum]

Agree with the above.

I have a 127mm refractor and a number of filters but only use my UHC and neutral density Moon filter with any regularity.

Clear skies!

[E621Keith]

I don't like using filter for scope under 6". If you are viewing through glare of sodium street lamp then a broadband filter can help, otherwise I wouldn't spend money on expensive narrowband filter. I found when I use narrow band filter in a small scope and look for faint fuzzy, the filter cuts down too much star light and my eye loses the focus reference. After that I won't be able to see the nebula because my eyes are out of focus.