How dirty is too dirty?

[Dealy]

I recently bought a GSO 250 F4 reflector and am in the process of setting it up for imaging.

I know mirrors don't have to be perfectly clean but what's the general opinion on when to clean?

Below is the mirror in question. Without a torch or flash pointed directly at the mirror it doesn't look that bad. Shine a torch down and "Whoa, how does that mirror reflect anything?".

What are your opinions?

[Nortilus]

distiilled water, cotton wool or microfibre cloth. No soaps or solvent. make sure bulk dust is blown off first with one of those rocket blowers used for cleaning cameras. rinse under the tap first then in small circular motion still under the running water gently wipe down the mirror. rinse in the distilled water and leave to dry. once dry you can just give the mirror a light polish with a microfibre cloth...thats how i do my newtonian anyhow

[sn1987a]

https://www.youtube.com/watch?v=9Y8xFnXFVGQ or squirt with water/dishwashing liquid followed by distilled water rinse :thumbsup:

[leon]

Ah, the dreaded torch down the tube, yep, it will let you see the smallest of dust particles and anything else that is happening down there.
A bit of a clean like suggested will bring it up a treat

Leon

[N1]

Mine looked similar. Cleaned it following this article:

http://www.iceinspace.com.au/63-345-0-0-1-0.html

Worked a treat, all done within 30 minutes.

[Dealy]

Much better :thumbsup:

Thanks guys

[rustigsmed]

nice improvement!
my Dob is dying to be cleaned.... it actually is that bad it effects planetary images i'll try and get to it this week.

[gaa_ian]

The Article here is how I have always cleaned mirrors and it has worked well & today this is how I clean them for my customers. However I have been wondering if the advent of the high tech Microfibre clothes has changed this at all :shrug:
Is a clean (turned each time) Microfibre cloth more effective, as sometimes it takes a few goes with the cotton wool balls or cotton make up pads (which are flatter and easier to use)