Which filters

[Reinholt]

Hello again

I'we been looking for filters for my new setup. I'll be going for a 200 or 250 Skywatcher dob, and probably a 5mm celstron x-cel lx eyepiece.

And are now looking at filters. Are there any filters you can't live without, like a UHC filter or moon filter?

Best regards Reinholt

[laudropb]

If you plan to look at Nebula then a UHC and OIII filter are very useful, but probably not in conjunction with a 5mm eyepiece.

[RT65CB-SWL]

I use a variable 1.25 inch Lunar/Moon. Also available in 2 inch.

[spike95609]

A moon filter is very useful in scopes of that size - you can look at the moon unfiltered when it's more than half full, but it is blinding and starts to feel very uncomfortable. I bought the Baader Neutral Density Filter but didn't like the yellow tint it put on everything, the Baader Neodymium is expensive but is more neutral on the colours and does just as good a job. I got this primarily because it claims to help with light pollution and improves the view on Jupiter, but I can't say I've noticed any difference with either to be honest. Others may disagree.

The only other filter I've got is an OIII to help with certain types of nebula. It hasn't seen exhaustive testing yet, but with the exception of the Veil nebula (which is quite invisible without it) I haven't exactly found it to be indispensable. I'd say that it's worth keeping one of these or a UHC around though as it isolates the necessary wavelengths and so massively boosts the contrast - the sky looks as black at 80x with it on as it looks at 200x without.

Yet I'd suggest caution before buying any filters as, with the exception of the moon, my experience has been that the improvements, if indeed there are any, are extremely marginal.

[John]

I've tried loads of different filters over many years including coloured ones, neutral density ones, Baader Neodymiums, Minus Violet, Contrast Boosters, Semi-Apo, Tele Vue Planetary, etc, etc.

The only ones I use now are UHC, O-III and H-Beta for enhancing nebulae plus a Kendrick white light solar filter for observing the Sun.

I regularly view the Moon at all it's phases with my 12" dobsonian. My eye quickly adjusts to the brightness and I find boosting the magnification (which I want to do anyway to pick out the features) reduces the brightness as well.

I think there is a lot of personal preference in filters and it is worth going through some to see if they do anything for you. The results of my "journey" through that process are the 4 filters listed above.

[Reinholt]

I have a 25% transmission Orion Moon filter that I like a lot for my 80 mm refractor and my 8" reflector.

Here are a couple of resources on filters that may be helpful.  I am just starting to explore filters but the ones Laudropb recommended are the ones I would recommend as well.

The use of filters

http://sas-sky.org/wp-content/uploads/2011/09/SAS-The-Use-of-Astronomical-Filters1.pdf

Filter overlay chart

http://www.karmalimbo.com/aro/pics/filters/narrow.jpg

Filter review

http://www.astronomy.com/~/media/import/files/pdf/8/c/7/0805_nebula_filters.pdf

Awsome links, thanks

[Reinholt]

Thankk you all for your inputs.

[LukeSkywatcher]

Honestly...............

I would not even bother with a Moon filter. You honestly dont need one. Yes the Moon can be bright but your eyes quickly adapt to that. It will not cause any long term damage.

I have to agree with John. My mainly used filters are UHC,OIII and i use a couple of safety filter for Solar observing.

Coloured filters for observing planets..............ive owned 2 sets and i'm still not convinced they serve any purpose.

UHC and/or OIII..........i think will serve you well if observing nebulae is your thing.

I should point out that the only time you may want/need a Moon filter is when the Moon is nearing full phase and that is the worst time to observe it because there is no contrast in detail of craters etc.

Save your cash and instead buy either a UHC or Oiii filter.

To be honest you'll get more use from a UHC.