Binoccular tune up

[Dog Star (Phil)]

OK. I've tried a forum search but I've either used the wrong parameters or there really isn't anything about this on the forum as yet.
I've got two specific questions -
1. What is the best method for cleaning binoccular lenses - ie, do I need to use distilled water, would methylated spirits be better, can the lenses be wiped with a soft cloth or is that a no-no, is there any danger of water or cleaning fluid getting into the body or housing, is it better to remove the lenses for cleaning, if so how, or is that a no-no too?
2. I seem to remember once someone telling me that binocculars can and should be collimated. How does one do this?
The objective lenses on my nokkies have picked up a grimy film from dew exposure, I think and it's not the sort of thing that will respond to a lens cleaning brush.
I've also noted that focusing on a mountain top at a distance of several km's produces a faint but annoying purple line or sillohuete where the mountain top meets the sky so I'm guessing that something is out of whack.
The nokkies concerned are AOE 20x80's, if that is relevant.
Any advice would be much appreciated. Cheers.

[PhilW]

With regard to point two: if you get back in touch with AOE, they can send you a cheat sheet they have prepared which tells you how to collimate these big binos. But you only need to do it if you can't merge the images when you look through them.

I suspect that purple line you mention is chromatic aberration; which is to say, it is inherent to the optical system.

[Kevnool (Kev)]

Sorry phil i dont know a darned thing about nokkies but your answer will come soon......Cheers Kev

[ngcles]

Hi Phil,

I'd be paying a visit to your local camera store to get the supplies to clean the objectives and eyepieces on the binos. It's not hard.

Most serious camera stores sell a lense cleaning solution which will not harm the anti-reflection coatings on the lenses. You will also need some lense tissues which will also not harm the glass or coatings. These two items will cost you about $10- to $15- I'd reckon and the small bottle of cleaning fluid will last a long, long time. A little goes a loooong way. A bottle of the Kodak solution I buy usually (about 50ml) ends up mostly chucked out after 3 years (I figure it's reached its use-by date by then and buy another).

Buy a tiny spray-bottle (most $2- shops have these) that will take just a little fluid and spray a fine gossamer mist on the lenses. Allow it to do its work for a minute or so and then wipe gently with the tissue till dry. If it is still grubby, repeat.

Collimation. Only collimate if you need to. Most binoculars do not need regular collimation unless roughly treated or dropped. Get the cheat-sheet as phil suggested just in case, but ...

You don't seem to describe anything in the views that speaks loudly of mis-collimation. The most sensitive test is the stars. If the binoculars are mis-collimated you will notice every star is double -- with the same seperation and PA. If it is only a fraction out, you can usually manage to merge the two star images if you concentrate but in the daytime the double image caused by very slight mis-collimation is hardly noticable. If more than a little out, when viewing stars, they will all appear to be wide double stars and it will just give you a headache. If the star images are round and focus to single points there is no problem on the face of it.

As Phil has already remarked, the other effect is more likely chromatic aberration and simply inherent in any fast doublet lense -- live with it. The only way out of that aberration is to replace them with some ultra expensive ED or apo binoculars.

Hoping it is of some help.

Best,

Les D

[JethroB76 (Jeff)]

Don't mess with the collimation on your binos unless you're convinced they need it, and as others have suggested, your description doesn't really sound like they do...

[Ian Robinson]

There is or was a book on Binocular Maintenance and Repairs that could be hard once, check that out.

Yes most binos can be collimated, I've done my own from time to time.

I don't think going near the lenses with a solvent is wize. Seek lens solution from a good camera shop.

[ngcles]

Hi Phil,

I should have added this:

You wrote:

"... is it better to remove the lenses for cleaning, if so how, or is that a no-no too?"

No, no need to remove lenses from the binocular or from their cells. You are more likely to do harm than good by doing so for lots of reasons. The inside optical surfaces _should_ be clean unless the binocs have been opened. Just clean the outside surfaces as I have advised with the lense cleaning fluid and lense tissues and they will perform just like "bought-ones" again.

Best,

Les D

[Dog Star (Phil)]

Sincere thanks to all for your replies and words of wisdom. Looks like it's off to the camera shop for me tomorrow.
Thanks again, that's deeply appreciated!:th umbsup:

[Ian Robinson]

Originally Posted by JethroB76

Don't mess with the collimation on your binos unless you're convinced they need it, and as others have suggested, your description doesn't really sound like they do...

It will be obvious if they do .... double stars everywhere.

[erick (Eric)]

Do your collimation at daytime on a solid mount (or cushion etc.). If out of collimation in a horizontal direction - no real problem, your eyes can adjust for that. If out of collimation vertically, that is a problem and will cause eyestrain.

Yes, get AOE's guide notes. Difficult to describe how to do it - but best on a straight edge - eg. the sharp line of a gutter, perhaps a taut powerline. Normally a little tweak of one prism collimation screw brings them into good conditional collimation. If you have to adjust the intraocular distance (IOD) for someone else, the collimation may go out again. You need an expert to collimate them so they are fully collimated regardless of IOD.

Checking under the stars - line up on a bright star. Pull your head back until you are seeing two images of the star, one in each eye. Then move your head towards the eyepieces and allow the images to come together to merge. You want to see them approaching each other at the same vertical level. If one image is significantly above the other, you will either see double stars, or you will twist your eyeballs to bring the images together - but your eyes will hurt after a while.