Help with Contrast for nebulae and galaxies

[javajunkie2121]

Hi All.  I live in the hills surrounding the San Francisco Bay...so light polluted to a fair degree.  I have a 5.2" Celestron Nexstar 130SLT Newtonian scope..trying to improve contrast on nebulae and galaxies while using low magnification.

I've heard about light pollution filters as well as the OIII filter to make nebulae and galaxies stand out a bit more...would these work with a 130mm aperture without losing too much light?

[timetraveler3]

Hello,

My scope is even smaller, I have a 114 mm reflector. I live in a somewhat polluted area not too far from Minneapolis.  I recently bought a #82 blue filter.  I heard it is a good all around filter if you don't have any.  I like to look at the Orion nebula and this filter made a difference for sure. It darkened the background and brought out the features. The cloud around the trapezium was more visible. I may try others too but this works good, moon and Jupiter looked better too.

Gary

[AlexB67]

For a 130mm scope a UHC would be a good starter filter. One that is not too aggressive on cutting out too much light which is important for smaller aperture instruments. Many of the other filters like the OIII may be a bit heavy handed in the amount of light they cut out in such instruments.  The skywatcher UHC filter with 1.25 inch fitting is often recommended around here for being competitive in price here in Europe and performs well. There is a 2 inch version of it also but this will cost more.

A UHC will help with a lot of things but not everything. UHC are good on nebulae, planetary nebulae but not all types like reflection nebulae and not galaxies. A light pollution filter is more general purpose that may help with everything, though I have never used one, It depends if you have a lot of sodium lights sources around it will block that out, but not the other types of white lights you see appearing more and more around my parts, here in Europe anyway.

You may also find this a useful read how the various filters perform

http://www.prairieastronomyclub.org/resources/by-dave-knisely/filter-performance-comparisons-for-some-common-nebulae/

Good luck

[AndyWB]

I use a Baader UHC-s filter - it's supposed to be a little less aggressive than some UHC filters, so images should be brighter still in a smaller scope. It works well in my 130p.

However, it only works with emission nebulae - ones that emit light at specific frequencies, like the Orion Nebula. Reflection Nebulae and Galaxies reflect/radiate light at a wide range of frequencies, so a filter can't help with them, really.