Filters

[Allan]

Hi All,

This is my first post here. I am very excited to be getting back into astronomy after a 20 year break. I am impatiently waiting for a shiny new XT12g that should arrive anyday now.

Can someone give me some advice about filters. I prefer to spend a bit extra to get quality filters first up so I don't have to spend more later to update.

1. Should I buy 2" or 1.25" size? I assume 2" is more versatile because I can use those with a 1.25" eyepiece with an adaptor, but I can't use a 1.25" filter with a 2" eyepiece.

2. Is there any difference between filters used for visual and astrophotography? I want to leave my options open so I can use the same filters for astro down the track.

3. Does anyone have experience with the Orion range of filters? I was wondering how they compare to the other brands on the market.

I plan to get to as many star parties around Newcastle/NSW as I can with my new scope. See you there.

[ZeroID]

I'd be hanging off on the filters till you have used the scope a bit to see works for you in your particular location.
About the only filters I use are an Astronomik CLS ( Clear Sky for light pollution) which may or may not be necessary for you and a 13% Moon filter to help cut glare. I have a few colours but they are recommended only for certain planetary situations mostly.
I only use the CLS photography although it can help visually to see some dust lanes in Nebulae.

[Terry B]

Simple.
Don't buy any.
You will almost never use them.
The only time you might is looking at Mars when an orange or red filter increases contrast. Even then I just used an old photographic filter and rested it on the eyepiece.

[erick]

If you buy filters, Allan, and saving $s is not a major concern, yes, buy 2" filters which gives you maximum use.

Now, do you need filters? No, not really. But if you have then, it's always worth a try on different objects. All filters make things generally "darker", but that can be selective, so the contrast between things in the view can change. There are two I have and use the most - the DGM NPB filter which gives a stunning view on some objects - it is magic on the Carina nebula. The other is an OIII filter for when you are searching out planetary nebulae.

[Allan]

That's great info. Thanks for your input

[ZeroID]

Saved you a heap of money eh ? :thumbsup:

[barx1963]

I do use an OIII filter for teasing out small planetary nebs. For the really small ones it is the only wy to pick them out even at medium power.
For the bigger and brighter ones they are best without a filter.
Big faint ones (the Helix for example) also benefit if seeing or transparency is a bit poor.

I also have a nebula filter, really improves contrast on the bright nebulae (Tarantula and Eta Car notably) and dims the stars in the neb so enabling better views of the nebulosity, but certainly not essential. For tracking down the faint emmision and reflection nebs, non filtered seems to work better for me usually.

Malcolm