Sorry, I just had to post this:

I’ve been experimenting with coloured filters for a couple of years with telescope apertures of 130mm and under. It’s not always easy to use filters with low transmission rates on apertures under around 127mm (5 inches) in my opinion. I’ve come to some conclusions and settled on fourteen that I consider to be particularly effective.


This is a personal selection however and your mileage may vary. I’ve included the Baader equivalent to the standard Wratten filter numbers, as I often use the Baader filters in preference to their equivalent Wratten filters. The Wratten filters I’ve been using are all TS Optics (GSO). All have M28.5 x 0.6 threads. I’ve included the transmission rate for each Wratten filter.



1/ Wratten #8 Light Yellow, 83% T, Longpass 465nm:

Enhances the observing of subtle or faint lunar features like graben and rilles. Helps with seeing any detail in Jupiter's polar regions and some belt detail. Works well for Jupiter in twilight as it doesn't tend to wash out any surface features in certain light conditions. Can improve contrast in Saturn's rings and help with surface detail. Darkens some Martian surface features.

2/ Wratten #11 Yellow Green, 78% T:

Can show as much, if not more, surface detail on Mars as a Baader Neodymium filter and can darken maria. Exceptionally improves Saturn's rings and emphasises the Cassini Division, definitely improves colours and contrast in Saturn's surface features. Can enhance Jupiter immensely, especially red and brown features.

3/ Wratten #12 Deep Yellow, 74% T, Longpass 500nm/Baader Yellow Longpass 495nm:

Emphasises lunar features, especially maria and mountain detail. Enhances belt detail and polar regions on Jupiter. Darkens maria in contrast to lighter desert regions on Mars. Helps with Saturn surface detail. Can be good for observing any detail in the clouds of Venus. Useful for viewing planets in twilight as it darkens the surrounding sky.

4/ Wratten #15 Dark Yellow, 67% T, Longpass 510nm:

Good for twilight viewing and can work similar to orange filters in twilight and helps to darken a daylight or twilight sky. Helps with Venusian cloud detail and can help darken maria on Mars.

5/ Wratten #21 Orange, 46% T, Longpass 530nm/Baader Orange Longpass 570nm:

Can give more contrast than the #15 and works well for daylight or twilight lunar observing. Good for contrast on Jupiter's belts and Saturn's rings. Sharpens Martian surface features slightly.

6/ Wratten #23A Red 25% T/ Baader Red Longpass 610nm:

Can often reveal detail on a bright twilight Venus and is beneficial when the Moon is approaching full. Makes a daylight blue sky appear black.

7/ Wratten #38A Dark Blue, 17% T/Baader Darkblue 435nm Bandpass:

Can drastically sharpen, define and reveal the phase on a bright daylight or twilight Venus, even with telescope apertures as small as 90mm. May reveal cloud detail.

8/ Wratten #47 Violet, 5% T:

Similar to the #38A and works on smaller scopes with a very bright Venus (especially in daylight), although generally too aggressive for apertures under 200mm.

9/ Wratten #56 Light Green, 53% T:

Good with lunar contrast, helps viewing Martian polar caps, reveals red features and the GRS on Jupiter and Saturn. Good for reducing glare on Jupiter and Saturn when they are bright targets and is often useful used on a bright twilight Venus to reveal phase.

10/ Wratten #58A Green Tricolour, 24% T/Baader Green 500nm Bandpass:

Similar to #56 but with much less transmission, useful for reducing glare on Venus and Saturn, especially either at transit or opposition. The #58A, particularly, performs superbly on an extremely bright Moon, revealing detail, especially away from the terminator, without transmitting an overpowering sense of colour.

11/ Wratten #80A Medium Blue, 30% T/Baader Blue 470nm Bandpass:

Good all round lunar contrast filter. Excels as a contrast filter on a very bright Jupiter and darkens the GRS. Enhances Saturn's surface features and some ring detail. Helps with Martian surface features and especially revealing polar caps. Can show Venusian cloud details that aren't normally well contrasted.

12/ Wratten #82A Light Blue, 73% T:

Very similar to the #80A but can show a lot of subtle and faint lunar features better, especially ray systems, graben and rilles. Superb for Jupiter in twilight and definitely improves belt contrast. Can help with Saturn's rings and surface features. As good, if not better than the #80A, for displaying Martian polar caps.

13/ TS Optics/GSO Neutral Density ND96~06, 25% T:

Superb for cutting down glare on a bright Moon without introducing artificial colour. Can be stacked with other coloured filters to help on particularly bright targets.

14/ Baader Neutral Density 0.9, 13% T:

Identical to the ND96~06 but 12% less transmission.

The #82A is a good filter for small apertures, very good on the Moon and a twilight Jupiter.

 

The best all-around filter, the Swiss Army Knife of filters is the Baader Moon & SkyGlow filter:

http://agenaastro.com/baader-1-25-moon-and-skyglow-filter.html

This filter improves contrast on whatever you point it at. Moon features are sharper; almost as if they're in better focus. Surface features on Jupiter - the bands, and especially the Great Red Spot - just pop out at you, where before it's a struggle to see them. This filter lets me split the Cassini Division at Saturn if the seeing is good. When Mars was at its closest approach last year, this filter let me see the surface albedo features where I could not see them without the filter. I can't recommend this filter enough.

The reason for this, as I understand it, is that this filter cuts out some of the blue end of the spectrum. Remember those informercials for "BlueBlocker sunglasses" from years ago? Well, not trying to sell those sunglasses, but there is science to back that up. The blue light interferes with your eyes' ability to come to a complete focus.

 

You're welcome. With smaller scopes it's probably best to stick to filters with a transmission rate of 50% or greater, although a 25% ND filter should be fine. With your 60mm, f/13 I'm guessing a focal length around 780mm? So on a good night you might get around 138x maximum (60x per inch rule) on the Moon.

I'm convinced a lot of filter use comes down to exit pupil size. It's going to be difficult to get a large exit pupil on a slow scope.

I take it the 60mm is an achromatic doublet. It might be worth considering a Baader Fringe Killer.

https://www.firstlightoptics.com/all-filters/baader-fringe-killer-filter.html

I agree with jgroub about the Baader Neodymium 'Swiss Army Knife'.

 

As for gettting a LPR filter: don't. I wrote all about this in my blog. An expert from the International Dark-Skies Association came by to our astroclub last year to give us a lecture. Read up about it here (scroll just past halfway down the page):

https://jgroub.wordpress.com/2016/08/31/august-31-2016-plato-craterlet-and-lpr-filters-are-doomed/

 

I'll disagree with Mak in relation to the moon filter. Forget about the neutral density filters. Instead get yourself a polarizing filter. This will give you an infinitely variable percentage of transmission, between 1% and 40%. This is the one I have, and I think it's terrific.

http://www.telescope.com/Accessorie...ing-Filter/c/3/sc/48/p/5560.uts?ensembleId=14

 

I might try a variable polarising filter one day. They look a bit finicky for me to use though (I'm physically disabled). It's just another piece of kit to spend too much time shagging around with lol. They sound good, I like to thread stuff in and forget about it for a bit. I observe the Moon a lot, the ND takes away glare whilst adding no artificial colour. They can be stacked with coloured filters for very bright targets.

Oh no, I've got to try a variable polariser now lol.

 

Mak has turned into a full-fledged 'Filter-Nut,' a title I often use to describe myself to fellow astronomers. My Pedigree:




Yup - all filters.

Enjoy your #82 Light Blue. Those are very nice - on the Moon is great! And Jupiter, and.....Do let us know your findings! Feel the insanity!

Dave au Raul

 

Basic contrast filters can be useful though, I only have five 2" filters: Baader Fringe Killer, Neodymium, UHC-S, an Astronomik UHC-E and a TS Optics UCF2. Basically a light pollution filter.



It is sometimes better for contrast than the Neodymium. Cheaper too!

 

This is nearly complete:

FILTER MASTER-LIST.pdf

(hope this worked)

Dave & Sybil

 

I have the Orion variable polarizing filter which I think is good with longer Fl eyepieces like my 25mm and 18mm, but with shorter FL like my 4.7mm, according to my observations, the filter causes a notable drop in quality.

I can't look at the moon with longer FL without the VPF, it's a great tool after all.