Filters for DSO

[GaryPitts]

Brand new guy here.  Got an 8SE for Christmas and on the clear nights so far, I've been enjoying Jupiter, Venus, and the moon.

I've tried a couple of times to find Andromeda, but had no luck.  I know I have a lot of work to do.  My main question though is in regard to filters needed/desired for DSOs.  Should I always be using a narrowband Oxygen III filter or an 'Urban Sky Filter' or any of numerous other filters that are out there?  I live in a subdivision in a rural area.  2-3 acre lots.  No streetlights except for the few some homeowners have, but houselights.  Also, when looking for DSOs, is it best to be using a ~25mm eyepiece or something roughly double that?  What is the concensus for filters needed in the toolbox for best results?

Thanks all!

[swamp thing]

Hi Gary

Personally I would recommend you just use the scope as is for a little while before worrying about using filters.

However if you must........

For me nebula filters are the only filters that really work on DSO's and their use is limited to emission nebula.

I would limit my filter box to the UHC, O-III and H-Beta filters. Of these three the UHC is often described as the best all rounder, so it may be best to start with one of these. The UHC is also the least demanding on the user as regarding dark adaption and the various exit pupils with which it can be used. The line filters (O-III & H-Beta) place considerably more demand on good dark adaption.

As for eyepieces, this kinda depends how big your target is. Some of the big DSO will need very low power or you'll look straight through and miss them, other objects can be pretty small and can even appear stellar if not enough power is used.

Check sizes of objects before you begin the hunt

Most star atlas or apps will give an objects size for reference. These are usually photographic dimensions but normally are okay as a rough guide for visual.

Have fun out there

[NGC 1502]

Hi & welcome to SGL.

You have great advice in post # 2, I'd read it a couple of times.....

I'd upgrade the eyepieces first because they are used on every object, maybe get a UHC filter later on because it's only useful on specific objects.

When finding a new object, best to use the lowest power (highest number on the eyepiece) because that will show the largest area of sky, and give the go-to the best chance of success.  You can change to a higher power (lower number on the eyepiece) if necessary.

I'd read and reread the 8SE manual, some of the setup can be practised in daylight when you can see what you are doing more easily.

Many go-to issues are power related.  At the very least use fresh batteries, have spares on hand, and perhaps consider a rechargeable power tank before getting any filter.

Regards, Ed.

[Little Big Planet]

Hi & welcome to SGL.

You have great advice in post # 2, I'd read it a couple of times.....

I'd upgrade the eyepieces first because they are used on every object, maybe get a UHC filter later on because it's only useful on specific objects.

When finding a new object, best to use the lowest power (highest number on the eyepiece) because that will show the largest area of sky, and give the go-to the best chance of success.  You can change to a higher power (lower number on the eyepiece) if necessary.

I'd read and reread the 8SE manual, some of the setup can be practised in daylight when you can see what you are doing more easily.

Many go-to issues are power related.  At the very least use fresh batteries, have spares on hand, and perhaps consider a rechargeable power tank before getting any filter.

Regards, Ed.

Hi there. Regarding filters may i ask what they do or for example when i look at Orion nebula through my scope ( see below )  i see the grey haze and stars which amazes me in itself, but if i was to add a certain filter what difference would i see?

Thanks

[NGC 1502]

Hi there. Regarding filters may i ask what they do or for example when i look at Orion nebula through my scope ( see below )  i see the grey haze and stars which amazes me in itself, but if i was to add a certain filter what difference would i see?

Thanks

Hi Lee.  The closest I have to your scope is my 70mm refractor.  When I look at the Orion nebula through that, I can always see a certain amount of the nebula, but when I add my UHC filter, more structure within the nebula becomes apparent, more easy to see.  The stars within the nebula are dimmed, it's the nebula itself that can be better seen. If you want to see the 'trapezium' within the Orion nebula, take the filter out.

It doesn't transform the visual view into what can be seen in images, but a definite enhancement.   The UHC filter is not useful on galaxies or star clusters etc.

Last September, I traveled light with my 70mm refractor to Kelling Heath in north Norfolk.  It's the venue for one of the UKs largest star party.  With the UHC filter, I bagged the eastern Veil nebula, once considered a difficult object.

HTH, Ed.

The UHC is considered by many as the most useful filter to get, and I'd certainly agree with that.

[bingevader]

GaryPitts, I'd find the Andromeda Galaxy first with the set up you have, putting a filter on won't help you find it. Swamp Thing covers everything else.

A filter, as the name suggests, will filter or block out wavelengths of light that would otherwise detract from object you intend to view. For fainter objects, it may make them easier to see.

On M42, a filter should improve the contrast and enable more detail to be observed.

Cheers

To slow!

[Little Big Planet]

Hi Lee.  The closest I have to your scope is my 70mm refractor.  When I look at the Orion nebula through that, I can always see a certain amount of the nebula, but when I add my UHC filter, more structure within the nebula becomes apparent, more easy to see.  The stars within the nebula are dimmed, it's the nebula itself that can be better seen. If you want to see the 'trapezium' within the Orion nebula, take the filter out.

It doesn't transform the visual view into what can be seen in images, but a definite enhancement.   The UHC filter is not useful on galaxies or star clusters etc.

Last September, I traveled light with my 70mm refractor to Kelling Heath in north Norfolk.  It's the venue for one of the UKs largest star party.  With the UHC filter, I bagged the eastern Veil nebula, once considered a difficult object.

HTH, Ed.

The UHC is considered by many as the most useful filter to get, and I'd certainly agree with that.

Thanks for that Ed. I shall browse the web for a UHC. 1st stop first light optics.

[RikM]

As an example, here's a sketch I made a little while ago to try and show the difference I see on the Orion nebula with/without my UHC filter. This is using a 14mm 70° eyepiece in a 10" Dobsonian from typical suburban skies.

[Little Big Planet]

As an example, here's a sketch I made a little while ago to try and show the difference I see on the Orion nebula with/without my UHC filter. This is using a 14mm 70° eyepiece in a 10" Dobsonian from typical suburban skies.

Thank you 4 that. I also read that the filter helps block light pollution which is something I need!!! Unfortunately first light optics have sold out of that filter but I hope when I am back from Egypt they will be back in stock.

Again thank you 4 the sketch