When is a dirty mirror in need of a clean ?

[Brett]

When is a dirty mirror truly dirty ? I ask because after ten months in storage my 130p`s mirror is looking mucky and in need of a possible clean. Is it possible for someone to post a pic of a mirror that needs cleaning and also a mirror that is dirty but not dirty enough to warrant cleaning:icon_confused:. This will be the first time I attempt a clean so I`m a bit scared and I don`t want scare myself if I don`t need to.

Thanks

Brett

[mdstuart]

They will tell you on here a dirty mirror will not affect your view until its so dirty you cannot see your face reflected in it.

I have cleaned my mirror using the running water and swishing of cotton wool method..which they will also tell you about on here..and its fine.Just take your time and have a lot of patience and do not try to get perfection at the end and you will be just fine..

Mark

[Capricorn]

Suppose the only real answer is "When you decide it is."

Although the mirror may be dusty and still reflect a large percentage of the light I would aslo say that dust will cause a diffusion of the light and so you get a less well defined image.

Which in this hobby is also pretty important.

As said it is really up to you.

Think we are a little too careful on the optical bits. I wear glasses, they are antireflection coated, had this set 4 years. I clean them with tissue, shirt sheve, towels, bog paper. I must do it several times a day. The coating is still intact, the glass is not marked at all and once cleaned they are clear as a bell.

Why the instances of don't touch a lens, only use specialised fluid, only touch very gently, even don't touch at all get a specialist to do it.

[Astro_Baby]

Theres a differenmce in mirrors - you shouldnt touch them because unlike a lens they are a very thin film on a glass plate. By putting pressure on them you can distort the mirrors figuring. How bad you can mess it up I dont know - I always err on the side of caution and I am not inclined to make a guinea pig of my own mirrors.

You can clean a mirror easy enough with care and patience so its not terribly hard. For myself I try and keep cleaning to a minimum.

[Doc]

As long as it's not like this one

[Brett]

Thanks for your replies with regards to cleaning. I decided last night to bite the bullet and give the secondary a good clean and thankfully it all went well. I cant take all the credit though as it was my better half's impeccably soft fingers that did the delicate cleaning bit, all I did was remove the mirror and rinse with distilled water and re-install.

Thanks again

Brett

[LukeSkywatcher]

Doc i think that mirror is a case for replacement, not cleaning.

[Doc]

Doc i think that mirror is a case for replacement, not cleaning.

LOL could still see M31

Actually only kidding it's not my mirror, just a pic I found of a dirty mirror.

[narrowbandpaul]

.....when the moon looks faint!