Jump to content

Cleaning a refractor lens

lw24

Recommended Posts

lw24

lw24

Posted
Posted

Hi all,

I just recieved my delivery of my Baader Optical Wonder fluid, microfibre cloth and Lenspen Hurricane Blower.

My refractor (Startravel 120) lens is getting a bit dirty. I can see a fair amount of dust on the objective lens, along with some sort of fingerprint/smudge, which I have no idea of how it got on there...

A quick side note, alot/most of the dust I can see seems to be on the second lens (not the primary), so I'm assuming I'm not going to be able to clean that.

So, how should I go about cleaning my lens? I have the above equipment, plus some standard Kleenex tissues, and some Johnsons baby Q-tips, which are 100% cotton. I've seen so many different techniques stated, and now I don't really know what to do, incase I get it wrong and ruin my first telescope.

Could someone list a sort of step-by-step method of cleaning my lens with the equpiment I have stated.

Cheers!

Link to comment
Share on other sites
John

John

Posted
Posted

The lens cell on those is really easy to remove from the scope - it simply unscrews from threads around the top of the tube. You need a bit of care when putting it back on to make sure you don't cross the threads.

Once off, the whole assembly containing the lens can be turned over so that you can get access to the rear surface of the inner lens element (there are two lens elements that make up the objective lens which may be separated by 3 small foil spacers - but you don't need to take the lens elements out of their cell to clean the front and rear surfaces.

Follow the instructions on the Baader fluid carefully (eg: spray it onto the cloth, not the lens) be gentle with it and you should be OK.

I would not touch the lens with anything other than the Baader cloth, but then I'm possibly over-cautious with lens coatings having wrecked a decent eyepiece once :)

Link to comment
Share on other sites
NGC 1502

NGC 1502

Posted
Posted
So, spray the baader fluid onto the baader microfibre cloth, then clean it. Then use a dry part of the cloth to clean any smudges?

Yes, that would be my method. Once the lens is very nearly

clean, you can 'huff' on it, and very carefully wipe any last

smears. But perfection is not required, a few minor smears

won't affect the view, so I always quit while I'm ahead :)

Regards, Ed.

Link to comment
Share on other sites
Rob

Rob

Posted
Posted

Take it slow.. John is quite right. Spray the cloth, not the lens. do not rub the cloth on the lens, let it glide round. reapply by over folding the cloth and respray the cloth if needed until done. Don't be too afraid with this, coatings are quite tough, but if stuff (pollen usually) is not lifting don't get carried away with rubbing, thats the key here.

Rob

Link to comment
Share on other sites
lw24

lw24

Posted
  • Author
Posted

What about the second lens? I don't really want to take my telescope all apart, I'm only 14... :)

If the dust on the second lens won't affect visual performance, then I'm happy to leave it.

Also, I can't remove the dew sheild from my telescope, it just won't come off :eek:

Link to comment
Share on other sites
John

John

Posted
Posted

If you are not comfortable doing this then by all means don't do it. Just use the cleaning kit, as suggested above, on the surface of the lens that you can get to from the front of the scope.

The stuff on the lens will be having virtually no noticeable negative effect on the images anyway so there is no need to put yourself in a stressful situation. Only do what you are comfortable in doing.

Link to comment
Share on other sites
NGC 1502

NGC 1502

Posted
Posted
So I should only clean it when it gets really dirty?

Yes, I think that's correct. I used to fuss over the slightest

speck on my optics. When I joined an astronomy club in 2002

I was shocked by the state of some of my clubmates mirrors/

lenses, and realised I was being too fussy.

I keep stuff reasonably clean, but don't obsess any more.

Regards, Ed.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.