Filters for planets-any recommendations.

[hotspur (Chris)]

Well with all this planet activity,the roof has been rolled off the observatory this week,and I have had the best viewing ever in my life of Mars-the detail I have been able to see through my 4 inch Vixen refrator and a Naglar type VI 3.5 mm eye piece has been quite amazing.Also used a 7 mm and 6 mm eye piece this week as well.

But what about filters for planets?? is this a good idea? if so which ones and where to buy?? I have not bought any astro gear for years,so not familiar with shops and retail outlets anymore.

I did read a thread on filter recommendations for filters,but that seemed more for nebula viewing,So thought I'd ask - thanks for any pointers.

[janoskiss (Steve H)]

I recall pale blue #80 or 82 (??) being somewhat helpful. Whatever the colour, pale, i.e., high transmission is best. The strong colour filters are a waste of time for visual imho. I experimented with colour and neb filters for a couple of years. On planets the best results were still very subtle but kind of nice. The hassle of fiddling around with filters got tedious after a while so I sold all my filters. Found it more helpful to just sit still and observe.

Mars may benefit from EPs with a slightly "warmer", ie reddish, colour balance, like some Televues have (eg plossls, type 6 naglers).

[MortonH]

In a small scope like a 4" you need a filter with high transmission. I would only consider these two:

http://www.bintel.com.au/Accessories...oductview.aspx

http://www.bintel.com.au/Accessories...oductview.aspx

[janoskiss (Steve H)]

@MortonH Bingo! #82A was the one I was thinking of.

[Stonius (Markus)]

I don't use planetary filters for visual because I want to see the actual planet as it is, and I feel the slight contrast boost of certain features is overshadowed by having a strange colour cast over the whole thing.

But I wonder; Is there a photographic advantage to filters?

Say you used a #23A Light Red. You could use it to enhance the contrast of the planet in other wavelengths by using it as a mask, or by mapping the colour into other wavelengths, like they do with narrowband SHO deep sky stuff. Has anyone tried this?

Markus

[bytor666]

IMO, from 4" to 6" scopes, no filters are needed.

[Don Pensack]

Each filter will add a little bit of detail and it may be necessary to use several filters to capture all the detail you can see.

With a 4" (what I use on my patio), I've found the following filters useful:
Jupiter: #82A light blue (dark bands), #80A Blue (bands again), Baader Contrast Booster (enhancing bands again)

Mars: #25 Red (dark markings stand out), #23A red-orange (dark marking stand out), #21 Orange (sandstorms and desert features and dark markings), #15 Yellow (sandstorms), #82A light blue (ice cap and limb clouds) #30 Magenta (blue and red features simultaneously), Baader Contrast Booster (desert features and dark albedo marking simultaneously--my favorite Mars filter)

Saturn: #82A light blue (bands on planet's surface), #12 yellow or #15 dark yellow (details in the rings)

My best view of every planet has been in perfect seeing at high power.
But each of the above filters has helped me see one feature or another.

Be sure to use at least 100x for Saturn, at least 80x for Jupiter, and at least 100x for Mars. If the seeing doesn't allow that high a magnification to be used, you're not going to see much.

The good news about filters is that by restricting bandwidths in the spectrum, they also reduce the effects of seeing conditions.
For me, Mars is sharper at 200x with a Contrast Booster filter than it is without a filter.

[Nikolas (Nik)]

I have one of these and they are awesome for planetary

[Don Pensack]

Originally Posted by Nikolas

I have one of these and they are awesome for planetary

The Moon & Sky Glow filter is usable on more planets than the Contrast Booster, but on Mars, I found the Contrast Booster better. On Jupiter, it was a draw. And on Saturn, no filter at all works best, though a yellow filtr of some sort will make the ring detail stand out.

The M&SG filter works OK on Neptune and Uranus, too, if viewing through a large scope.

[Stefan Buda]

Viewing Mars through colour filters is very useful for identifying transient features like dust storms, clouds and hazes.
A red filter completely eliminates atmospheric hazes and reveals albedo features and dust, while a deep blue is like magic in making the albedo features disappear revealing all the atmospherics. Orange is best for seeing dust activity.
I never tried filters on small scopes though and I don't think small scopes are very useful for planetary observing anyway.
On my 16" planetary I can use the same interference filters that I use for imaging but in the past I used colour glass filters that worked just as well and are a lot cheaper.
Saturn has low surface brightness so I don't think filters would be very useful and I have not tried Jupiter.

[ausastronomer (John Bambury)]

Originally Posted by hotspur

Well with all this planet activity,the roof has been rolled off the observatory this week,and I have had the best viewing ever in my life of Mars-the detail I have been able to see through my 4 inch Vixen refrator and a Naglar type VI 3.5 mm eye piece has been quite amazing.Also used a 7 mm and 6 mm eye piece this week as well.

But what about filters for planets?? is this a good idea? if so which ones and where to buy?? I have not bought any astro gear for years,so not familiar with shops and retail outlets anymore.

I did read a thread on filter recommendations for filters,but that seemed more for nebula viewing,So thought I'd ask - thanks for any pointers.

I gave a presentation on Visual Astronomy and the Use of Filters at the Ice In Space Astrocamp (IISAC) in 2011. A hard copy of my presentation has been uploaded to the IIS website and can be accessed here

http://www.iceinspace.com.au/forum/s...ad.php?t=89413

Whilst most of the presentation was about Deep Sky Filters I did cover planetary filters as well. Pages 26 and 27 of my presentation summarises what filters enhance which specific features of each planet. The other thing to be aware of is that one of the overall very best planetary filters is actually a broadband light pollution reduction filter. Whilst these aren't designed as planetary filters they do a very good job of it. Essentially they reduce irradiation (distortion of the boundaries between light and dark) and by softening the tone of one colour against similar adjacent colours.

Some of the better visual Broadband filters are the

Lumicon Deepsky
Orion Skyglow
Astronomiks CLS

There are also quite a few others at varying price points. Whilst one of these is a lot more expensive than a coloured filter you only need one and not half a dozen and it would have other uses as well, particularly if you observe and image from less than ideal sky conditions.

Cheers,
John B