Filters

[Ganymede12]

I've seen lots of different filters advertised and I was wondering, what exactly do they do?

Obviously solar filters makes for safe solar viewing but why would you need moon filters or planetary filters?

[sologuitarist61]

As I understand it a moon filter is a neutral density filter and cuts the amount of light to the eye (the magnified moon being particularly bright) and this for me gives my eye enough relief that the image appears sharper with more contrast.

Went to a star party a few weeks back and the kids there were saying that my image was the best one there, which was strange as there were scope costing many times the worth of mine for them to look through. In discussion afterward it turned out that mine was one of the few that had a moon filter fitted - so the image appeared to be better as the eye was not struggling with too much light.

[David Smith]

The planetary filters help to bring out the detail in planets such as Mars and Jupiter. The effect does tend to be subtle but noticeable. Need to be a bit careful about which ones you use / buy as some can block a high percentage of the light, leaving a very dark image. I use planetary filters almost every time I look at the planets.

[Ganymede12]

Does anyone know if it is possible to get filters for my Sky-Watcher SK707AZ2?

[rwilkey]

Any filter with a 1.25" fitting will suit your eyepieces as they are screwed into the back of the eyepiece itself usually.

[Codmate]

I've found that a variable moon filter is virtually mandatory for prolonged lunar observation.

[garethmob]

if your eyepeices are 1.25 then yes, iv got a full set of colour filters for 1.25 eyepeices as well as a baader neo dynium filter (this is like a moon filter cutting the light but it also makes images sharper as well)

there are other filters like oiii filter and UHC but they are designed more for 3" - 6" and 8" and way above telescopes. these reduce Lp but they also pass differente wave lengths of light for instance 0iii is good for the veil nebular

if you come on the 28th your more than happy give any filters a go in either my scopes or yours

[Moonshane]

There are lots of different filters broadly (well, exactly really) what they do is 'filter' out certain wavelengths of light. They don't actually enhance or brighten anything, they simply remove certain light so that targets that are emitting certain colours/wavelengths are less reduced by the background 'noise'. I generally prefer an unfiltered view where I can.

I'd summarise them roughly as follows:

• Moon filters - I personally don't like them but many like the fact the filter reduces glare on the moon.
  
• Light pollution filters - remove effects of some streetlights and also the moon when used to enhance the apparent contrast in the sky. I use my Baader Neodymium filter for the moon, Mars and Jupiter but not for LP even though it's bad where I live
  
• Planetary (coloured) filters - I loathe these but some swear by them.
  
• Solar filter - must be used with most scopes to avoid eye injury. Reduces the light by 99.999% so that sunspots etc can be seen. You can also use other filters such as th Baader Solar Continuum filter to tease out a little more detail.
  
• Narrowband filters - Oiii / UHC generally. These are very good and can be used with all scopes to see fainter objects such as emission nebulae. The exit pupil here is more important than the aperture with larger pupils normally required to get best use. Darker skies and more aperture also enhance the image of course.
  

[michael.h.f.wilkinson]

Previously I used only a solar (objective) filter (obviously), a light pollution reduction filter (wide band) which blocks many emission lines of outside lighting like mercury and sodium lights, and a narrow-band UHC filter, which only passes light emitted by emission nebulae. Only recently did I get a quality moon filter and it is easier on the eyes. I could easily do prolonged observations without, but when you stopped you had the feeling that one eye had gone partially blind (no binoviewer).

I never use planetary filters. I tried them in the past, but did not get along with them. Maybe I should try them again at some time.

[stonemonkeylives]

Don't know if you read through this in the Primer and tutorial section, but should help;

http://ww.http://stargazerslounge.com/primers-tutorials/38541-primer-planetary-filters-guide.html

[rwilkey]

The polarising moon filter is a great piece of kit and I can recommend it if you are a lunar observer. Like Moonshane, I loath the coloured filters, they don't do anything for me, just colour the view. For small apertures like yours, I would recommend the UHC-S filter for nebulae, as it doesn't darken the view too much, like the UHC or OIII filters, though I use both successfully in my C100ED. Great contrast in nebulae!

[Moonshane]

ps don't forget that galaxies are only enhanced by aperture and darker skies.

[michael.h.f.wilkinson]

ps don't forget that galaxies are only enhanced by aperture and darker skies.

A broad-band LPR filter can actually work on galaxies and reflection nebula, depending on the kind of LP (sodium and mercury dominate in my neighbourhood). It helped me pick out M108.

[tjr]

Good thread. I'm looking to get a LP filter myself. My Skymax 127 gives me incredible views despite its compact size and viewing conditions (I observe from London - sigh...), but any improvement is always welcome. Can someone with a bit of experience using either SW light pollution, Baader neodymium or UHC filters help my decision making?

[garethmob]

iv got the baader and personally to me it makes a difference, its also good if your doing any webcam / videophotography as it has a IR cut filter inside the neodymium

i havent compared the other 2 but i do like the baader

[rwilkey]

The Baader Neodynium Filter is the best one in my view - more versatile, though the Sky Watcher, a bit cheaper, is very good in my view.

[tjr]

Thanks guys. Robin, you say the neodynium is more versatile... do you mean as a moon filter too? Will this mean that the views are darker than with the SW filter?

[garethmob]

i sometimes screw my moon filter to my neodynium just to view more confortable and in more clarity

[sinky]

The Baader Neodynium Filter is the best one in my view - more versatile, though the Sky Watcher, a bit cheaper, is very good in my view.

In what way is it more versatile?

Is it worth paying the extra £30 for the 1.25" versions?

[rwilkey]

The Neodyniun can be used as a moon filter as well, it also helps with detail on planets.

[Ganymede12]

Would it be worth buying filters for a scope as small as mine?

[garethmob]

Well once you have them you have them for when you upgrade your scope . Astroboot (on scope and sky's) usually have Agee coloured filters cheap

Sent from my iPhone using Tapatalk

[rwilkey]

Ganymede12, I use them on my C100ED and they are fine, should be OK on a 70mm, will appear to darken the sky more but they should be of benefit, try the Neodynium first and see how you get on. For nebulae, I would suggest the UHC-S as this has a broader band pass.

[Ganymede12]

Whoa! The UHC-S nebula filter costs the same as my telescope and I'm trying to save up for a SKYLINER 200p dobsonian!

The Baader Neodymium Filter doesn't seem too bad though, but it will still delay the dobsonian. Should I get the filter or the dobsonian first?

[rwilkey]

The Skyliner would be a better investment. Sorry, I didn't look at the price, but I do have one and it is very good.