Filters - how necessary and what colours?

[Moon Lander]

I appreciate that a Moon filter is essential to allow you to view the detail witout blinding yourself. What about other filters though? Do they significantly enhance the viewing experience when looking at the planets, or are there better things to spend money on? If filters are recommended, which are the most useful initially? Once again, thanks for any advice.

[barkis]

Filters can and do help bring out planetary detail.

A Red No25 can enhance the polar caps of Mars.

23A Light Red can help with Jupiter and Saturn's Belts.

38A Dark Blue will help with Jupiter's Red Spot, and may bring out some Cloud detail on Venus.

15 Dark Yellow aids the seeing of Saturn's, and Jupiter's Equatorial regions, and also enhances Lunar features.

Just a few, but there are lots more that others will bring in.

Ron.

[great_bear]

I've not had much luck with filters in the "general" sense - but here's a couple I wholeheartedly recommend - which I use regularly.

- #29 "Dark Red" - great for lunar observing whilst offering some dark-adaptation protection

- #15 "Dark Yellow" - great for darkening the blue summer sky whilst observing the moon in early evening when it's still light outside.

[Talitha]

This page from Lumicon is the best one i've ever seen regarding filters, hope it helps.

Different colors do enhance certain planetary features but TBH, i've never found that they can show me anything that's not already visible without them... it doesn't take long for your eye to train itself. I have a dozen color filters and only use two... red for daytime lunar viewing, and yellow to cut the CA in my widefield refractors (IMO it's every bit as good as my WO VR-1 filter).

[Digz]

I tried my filters from my Revelation Photo-Visual Kit last night and whilst they do bring out some detail on certain objects it took me a while to get used to seeing the subject bathed in whichever colour filter I had. What I havent considered is the use of these filters when taking photos to see if this is any good.

I dont really own any other filters at the moment but a LPS filter or OIII is on my list to help with polluted skies and bring out details on certain DSO's.

[davy999]

I also have the revelation kit.

Are these useable for CCD astrophotography using a mono CCD?

[Moon Lander]

Hi Talitha,

Thanks for the link, that gives good information on what's available.

BTW, I like your feature in Sky at Night, I think sketching brings a different dimension to the subject.

[crazyjedi]

Filters are useful but usually under clear skies and steady viewing. Even at best the improvements are subtle. Don't expect planetary detail to snap into view with a filter. They normally enhance that which is there already. The light red and blue filters have enhanced Jupiter nicely in the past. If you were expecting magical results you will be feelin let down but you may get some nice detail with practice and patience.

Happy Views!

[gareththegeek]

From reading the leaflet that came with my lunar filter I get the impression that filters are generally for scopes of 8"+ aperture.

[great_bear]

I get the impression that filters are generally for scopes of 8"+ aperture.

It certainly doesn't hurt to have more aperture when using filters. However, it's a bit too much of a "broad-brush" statement to be that specific.

What would be more helpful (given that all exit pupils of a specified diameter are of the same brightness, irrespective of aperture) would be to specify a recommended exit-pupil for a given filter.

e.g. "This light pollution filter should be used at exit pupils 2mm and above" or perhaps "This moon filter is not recommended at exit pupils below 1mm"

[crazyjedi]

There are some filters suitable for smaller scopes but you do have to check the pass bandwidth. the tighter the bandwidth restriction the more light grasp you'll need to see anything through it.

The Baader UHC-S is quite useful for smaller scopes.

[Talitha]

Hi Talitha,

Thanks for the link, that gives good information on what's available.

BTW, I like your feature in Sky at Night, I think sketching brings a different dimension to the subject.

You're welcome, and thanks so much for your kind words.

[krs01]

so i don't have to start a new thread,which filters are best for planetry observations?