Planetary Filters?

[Coco]

I tried the search first

Can anyone suggest would I benefit from using a filter for the Dob, will it increase the detail? I'm thinking also would it be useful on the Moon? Not actually on it I mean

I'm also thinking about buying fringe filter for my 600/6 ED Frac as the Moons got a yellow fine edge.

Guy..

[brianb]

"Minus violet" will probably fix the fringing in your ED 'frac.

Moon filters (to reduce glare) are subjective; I favour a deep red (Wratten 29), which helps preserve night vision. Others prefer green (58) or neutral density. Many like dual polarizers, which are adjustable; I find them fussy & prone to scattering too much light.

Planets are different because they do have colour contrasts which can be enhanced by filters (when the filters are good quality). Visibility of dark markings on Mars is enhanced by orange (21) or light red (23a). Blue (80a) shows up atmospheric cloud on Mars but pretty well stamps out the dark markings. The same blue or light green often helps contrast on Jupiter. Saturn is too faint for filters to help me at all. Venus is only helped by a deep violet (47) which is so dense that a large aperture is necessary to get sufficient light through ...

... but filters are not a "magic bullet", they may improve detail selectively but the effect is marginal rather than profound. They're no substitute for learning to see. The only filter I consider essential is a Moon filter; it's just too bright to be comfortable without one.

[russ]

I agree with Brian. The most essential filter is a moon filter of some sort. I prefer an ND4 for my scopes, both of which are 8" aperture. This only allows 25% of the light to pass, so quite aggresive. Although i've seen it suggested that an ND9 (13% pass) is appropiate for that aperture. The ND doesn't alter the colour cast, so you get a natural looking view.

Another filter that is highly useful is a Wratten #12 yellow. Also works with the Moon for reducing glare plus i've found it a good filter for Mars too.

Bit late recommending filters for Mars now but #21 Orange is great for surface features. I have #23a too but i find this is too aggresive with 8" aperture. And from what i've read (didn't read it before i bought) the 23a needs 10" or larger aperture to be of much use.

I have #47 Violet for Venus but as with 23a i didn't do my research thoroughly enough and it's highly unlikely it will be of my use with scopes. But i'm keeping it for the time i observe Venus using my local clubs 14" SCT.

I'll give a thumbs up to the Antares range of filters. My first filter was a Lumicon #21, i then aquired a set of Antares colour filters that also included another #21. The view through both filters was identical. On that basis, seeing that Lumicon are highly regarded, i wouldn't spend a large sum on colour filters. The Antares are perfect for the purpose.

Russ

[Talitha]

My set of 12 color filters are rarely used anymore. They were purchased in my Newbie days and were a very good learning tool in planetary feature detection, but were put aside when my eye became trained.

The red filter is still used for increasing the contrast (and counter-acting the blue skywash) during daytime lunar observing, and medium blue is a good substitute for a Moon filter at night. IIRC, light blue helped me the most on Jupiter, light yellow on Saturn, and orange on Mars.