PDA

View Full Version here: : Which filter first?


DiamondDust
10-12-2009, 02:47 PM
Hi everyone, :newbie:, and relatively new to astronomy, but keen as mustard and my husband thinks I've turned into a vampire! Anyway, I've had a 10" Dob with the usual GSO Plossl eyepieces for about 2 months and have been learning what they're capable of. There's no way I can afford to change to better lenses just yet, but I think I'm ready to try filters to enhance my views (planets, galaxies, nebula etc., not necessarily moon). I'm also thinking something to offset light pollution. I don't do astrophotography (well, not yet....). Anybody out there any suggestions please? (Oh, and what are tags:question:)

wavelandscott
11-12-2009, 12:49 PM
Do a search in this forum for Light Pollution Filters and you wil find lots to read...

In a quick recap...

Are there filters that will work...yes...however, there is no filter that can substitute for a dark sky. In most cases I would suggest saving your money and investing in "better" eyepieces as I think most people will get more long term benefit from a good eyepiece instead of a filter.

I have an Astronomics Light Pollution Filter and it will block certain wavelengths of light (like those from streetlights)...and they do improve the views of some night sky objects (and detract from others).

I usually encourage people to get a UHC or NPB filter if they are so inclined instead of a Light Pollution Filter...a UHC/NPB will act like a Light Pollution Filter but even more so and therefore in my mind are a better value.

While a light pollution filter will help block unwanted wavelengths of light, they will not improve your eye's ability to dark sky adapt...I think this has more of a negative impact on viewing in town than many other things...

Do read the other threads when you get a chance and ask away...lastly, if you can "try before you buy" from some other Astro folks...

Clear Dark Skies...

tnott
11-12-2009, 10:09 PM
Remember that nebula filters only help on emission nebulae. They won't help on star clusters or galaxies. Need to get to dark skies for those.

General "Light Pollution" filters are just broadband nebula filters and frankly pretty useless.

Narrowband UHC type filters give better contrast on most emission nebulae.

Even more narrowband OIII filters have a really dramatic effect on certain diffuse nebulae and planetaries. They blot out too much light for smaller scopes but are OK in my 10 inch.

Not the same thing as going to dark skies but they do make the nebulae more visible in moderate light pollution.

I don't use filters when viewing planets or the moon. Never found that they helped much.

BTW-you'll find these filters are not much cheaper than eyepieces anyway!

pgc hunter
13-12-2009, 11:39 AM
I'd get a UHC filter to start off with. Works on almost all nebulae including planetaries and doesn't dim the background stars as much as an OIII. A good all rounder.

DiamondDust
14-12-2009, 11:58 AM
Mmmm, thanks for your input guys. Reading between the lines I think you're steering me into leaving things alone for a while and perhaps saving for better EP's. Then some balancing weights, then some..... the list goes on doesn't it! :xmas: Happy Xmas and good viewing in 2010. Ingrid

Rodstar
14-12-2009, 06:50 PM
Hi Ingrid, great to have another female amateur astronomer in our midst! For some reason we are over-represented by males by what seems like a factor of 50 to 1!

I use my OIII filter the most. But I suspect this is because I have larger aperture (20 inches) and so the UHC filter is less necessary (nebulae are far brighter than in a 10 inch scope). I like to hunt down dim planetaries, and for this purpose, the OIII is fantastic.

DiamondDust
15-12-2009, 12:05 PM
Thanks for the greeting and your input Rod:hi:. I see your equipment is rather large! Is it mounted onto the wheels or is it sat on a "trolley" and if so did you make it yourself? Do you drag it in and out each night? Re the filters, I'm going to save and get better eyepieces next year.:drink:Cheers and Happy Christmas

ausastronomer
16-12-2009, 09:18 PM
Hi Ingrid,

Rod is an excellent lawyer and a very ordinary carpenter. Whilst he is capable of solving the worlds' legal problems, he is totally and utterly incapable of building a telescope like that :rofl:

His scope and several others, including one of mine, was made by a good friend of ours called Peter Read, who has his own telescope building business called SDM Telescopes.

www.sdmtelescopes.com.au

They are as good as anything built anywhere else in the world and something to consider in a few years time if you and your hubby are still keen observers.

Cheers,
John B

Rodstar
19-12-2009, 07:08 AM
You will have no argument from me John about my carpentry skills.....glad you like my lawyering skills.....:P

that_guy
13-01-2010, 10:22 PM
what does the colour filters do?? do they make observing easier??

astro744
14-01-2010, 06:21 AM
This site http://www.lumicon.com/astronomy-accessories.php?cid=1&cn=Filters has all the info you need.