Dirty primary

[SmokeyJoe]

Trying to get my scope up and running after three years in it's box! Thought I'd have a go at collimation as it's raining, took it out of the box took the cap off of the end to find large bits of dirt on the primary.  I know enough to know to use a blower and not to wipe it but do I really have to remove it from the scope, never even collumated it before.  The pic shows only the largest particles there are seven or eight more not shown.

[Cornelius Varley]

If you clean it you will probably not see a difference in optical performance.

[Ibbo!]

I'd leave that as is and get it collimated

 

[Peter Drew]

Compare the size of the spots to the size of the secondary spot in the middle and you will see how insignificant the spots are!  

[laudropb]

Leave well alone . Collimation and enjoy the views. Those marks will have, if any affect.

[BXRO]

Those flecks are probably bits of old paint/packaging etc and are probably not to firmly attached to the mirror. Judging by the size of them they will not have a great impact on the performance of your scope. If you want to before you collimate the scope turn it so that the appature is facing downwards and give it a couple of soft taps with your knuckles, this may loosen them. If you want to be really brave put a vacuum cleaner hose down it and see if you can suck them off however DO NOT TOUCH THE MIRROR with the hose end, it will ruin the reflective surface.

[SmokeyJoe]

Ok, thank you, I will collimate, and wait for clouds to clear before panicking and doing something silly! There has definitely been a spider in the scope there were some bits of web when I took the cap off the appetite, might have something to do with it.

[ronin]

Collimate it first and get it working so you can use it happily.

Then think about cleanly the crud off. As it looks like "lumps" I would guess they are not adhered to the mirror surface, just fallen on to it. Good chance some will dislodge while you are collimating.

If they drive you nuts (they would me) then a gentle blower may move them. After that I myself would consider a soft camel hair artists brush to wipe over the surface.

[Nyctimene]

There's an old rule: if you are just considering cleaning the primary, don't clean it. You should be really convinced that cleaning (washing) is  absolutely necessary (e.g. grease, spoiled liquids). Then follow the hints you'll find on this forum; or have a look at the numerous Youtube clips on that.

The blower/artist's brush approach of ronin above sounds promising. If that should not work, leave it as it is. It will not harm your viewing.

Stephan

 

[iapa]

 

2 hours ago, Nyctimene said:

There's an old rule: if you are just considering cleaning the primary, don't clean it. You should be really convinced that cleaning (washing) is  absolutely necessary (e.g. grease, spoiled liquids). Then follow the hints you'll find on this forum; or have a look at the numerous Youtube clips on that.

The blower/artist's brush approach of ronin above sounds promising. If that should not work, leave it as it is. It will not harm your viewing.

Stephan

 

I remember seeing a thread somewhere, where the general consensus was is you can see the plooks on your face in the mirror, then doesn't need cleaning