Best filter for observing galaxies and clusters

[Alexh88]

Total newbie been told a uhc filter is best for observing galaxies and star clusters is this true if not wich filter should I use just for observation not astrophotography 

Edited February 17, 2023 by Alexh88
Wrong word used

[Stu]

12 minutes ago, Alexh88 said:

Total newbie been told a uhc filter is best for observing galaxies and star clusters is this true if not wich filter should I use just for observation not astrophotography 

Welcome Alex.

I’m afraid that in general filters don’t help too much for galaxies or clusters, because they emit light across a broad range of the spectrum.

UHC filters work by only passing specific frequencies which are generated by certain objects (things like emission and planetary nebulae) and filtering out everything else. This ends up improving the contrast seen against the sky background, but if used on Galaxies/clusters is just likely to reduce the overall brightness without helping the contrast.

You could try something like a Baader Neodymium Moon and Skyglow filter which is more broadband in nature, but can help control light pollution to a small degree.

It is often said that the best filter for galaxies is a tank of fuel to get you to a dark site; reducing the sky background brightness by getting somewhere dark is the best way to get better views of these objects.

[scarp15]

For those subjects, a filter is not required.

Galaxies do require a dark and transparent sky, a degree of dark adaptation and in some instances to apply averted vision. Use a low power eyepiece to detect, then increase the mag if deemed a 'brighter' subject. Other than a select few, reasonable aperture for when observing galaxies, will very much assist to. 

A UHC filter however is very useful for enhancing contrast in Nebulae and Planetary Nebulae.