Filters

[Moonboy (Gus)]

HI GUYS AND GIRLS
I have got a Celestron Power Seeker 127mm and I was told that if i buy a filter(s) I would be able to see planets better, is this true?

Gus

[tbentley]

Now, just before someone else says it....depends on where you point the thing. I only joke because I know very little about it and to just get it out of the way. However as I understand it certain colour filters will allow you to see some details more distinctly. It all depends on the target and the colour filter as to what more or less you will see. The others here will educate us both I'm sure.
Travis

[peter_4059 (Peter)]

I bought three coloured filters for this reason but regret spending the money on them. Others might have a different point of view.

[erick (Eric)]

Moonboy, search for threads on filters. There has been a number in the past year with good references to articles etc.

[Moonboy (Gus)]

Thanks Guys

Gus

[erick (Eric)]

Gus, for example:-

http://www.iceinspace.com.au/forum/s...ad.php?t=27821

[Moonboy (Gus)]

Thanks Erick

[rmcpb (Rob)]

The only "essential" filter would be the variable moon filter. Next would be the UHC and OIII filters for nebulae. The colour filters I "had to have" are very rarely used if ever.

[ausastronomer (John Bambury)]

Originally Posted by peter_4059

I bought three coloured filters for this reason but regret spending the money on them. Others might have a different point of view.

I agree with this. I own a heap of premium 2" colour planetary filters and while they each do "something" in a small way with different features on different planets I can think of infinitely more important and worthwhile toys to spend ones limited astro budget on.

I would rate a UHC filter as the most beneficial and it is very hard to go past the DGM Optics NPB in this regard.

Cheers,
John B

[ausastronomer (John Bambury)]

Originally Posted by rmcpb

The only "essential" filter would be the variable moon filter. Next would be the UHC and OIII filters for nebulae. The colour filters I "had to have" are very rarely used if ever.

Rob,

You keep on harping about the "necessity" of a moon filter for observing the moon. As I have mentioned previously I own a 2" variable polariser which gets used about once a year (if it's lucky), when my wife wants to look at the moon with me in the 18" scope. When I observe alone using the 18" scope on the moon I always observe it unfiltered.

Any filter on the moon reduces light and therefore invariably cuts down the amount of VISIBLE DETAIL.

There is no risk of damage to your eyes. You are looking at reflected light bouncing off a surface with a similar colour and texture to asphalt. Observe the moon in daytime and it isn't bright at all. It appears bright because everything else is so dark

To recommend a variable polariser as an "essential" filter to someone whose largest aperture scope is 5", is ridiculous IMO. You clearly have very light sensitive eyes and may find it essential, but that doesn't mean you should continually recommend it as a neccessity to the rest of the astronomical world.

Cheers,
John B

[edwardsdj (Doug)]

I really wouldn't consider filters with that small apeture. Filters block the light making the image dimmer and obviously coloured.

Apart from a variable polarising filter I occasionally use to show others the Moon (some people complain it is too bright) I don't find much use for them visually.

Until I started getting into webcam planetary photography, my filters spent years in thier box. I have been getting some mileage out of the red filter when imaging Mars lately. That's about it.

I so wish I had the $1000 I've spent on filters in the bank right now. Would really help with the EQ6 purchase.

[ausastronomer (John Bambury)]

I may add there are countless ways to reduce the apparent brightness of the moon when observing it.

Notably:-

1) Do not allow yourself to get dark adapted before you start observing.

2) Have some exterior lights on nearby or interior lights on nearby. Not in a position to introduce reflections, but to stop you getting dark adapted before you begin observing.

3) Use as high a magnification as possible. The higher the magnification the lower the apparent brightness of the target.

Cheers,
John B

[citivolus (Ric)]

I invariably get eye strain if I observe the moon unfiltered, even through a 90mm refractor. Personally I'd rather be comfortable while observing.

[ausastronomer (John Bambury)]

Just because you get eye strain looking at the moon unfiltered with a small telescope doesn't mean the majority of observers have the same problem.

To call it an "essential" accessory for everyone with a 90mm telescope is way off target.

Cheers,

[rmcpb (Rob)]

Originally Posted by ausastronomer

Rob,

You keep on harping about the "necessity" of a moon filter for observing the moon. As I have mentioned previously I own a 2" variable polariser which gets used about once a year (if it's lucky), when my wife wants to look at the moon with me in the 18" scope. When I observe alone using the 18" scope on the moon I always observe it unfiltered.

John,

Note the quotes around essential!! When people start observing they tend to shy away from the fuller moon because it is uncomfortable. Not saying it will do any damage, but it is very bright. A moon filter tends to make it more comfy and they tend to use it and observe the moon instead of avoiding it, as in your wife's case. As they progress the moon filter tends to stay in the filter box like all the others but by that time they are confident about observing the moon unfiltered and will continue to do so.

As for the rest of the filters none are essential is my point until the observer gets into the more specialist viewing demands based on their observing style, then it is time to invest in filters, like most other accessories.

[Stephen65]

I am a very regular observer of the Moon in scopes ranging from 90mm to 250mm. I never use a filter. I do own a variable polarising filter but I found it to be a waste of money because it reduces the ability to see fine detail and the brightness does not bother me.