Telescopes There is a layer of grease on the inner surface of the eyepiece How to remove it?

Hello, I'm in the optical industry. There are two possibilities for this, one is damping grease, the other is dust grease, which needs to be used inside the telescope, and because most of the greases are volatile, so if there are too many of them, and the manufacturer's degreasing process is not thorough during assembly (all deoiling needs to be done before the parts are assembled), then the glass surface will show lipophilic microscopic characteristics, so the oil will easily volatilize to the lens surface. This has also happened to our previous products, but they have all been singled out and returned to the factory (although the slight ones are also qualified).

If it's serious, it can be replaced, and if it's mild, it can be difficult.

You generally don't want to remove it, because the lenses, if you don't have pure alcohol and a cotton ball that is better for degreasing, then after opening, it can't be wiped clean. And there is a very dangerous possibility, that is, the more you rub it, the dirtier it will become (because the four walls of the eyepiece are dust-proof grease, once occupied, it is very troublesome.) This is a reminder and a warning.

You can refer to the lens wiping for reference.

If you just want to fiddle with it yourself, this kind of eyepiece can't be twisted down, you need to loosen the screws on the bottom bracket, and then lower the eyepiece as a whole. This grease volatile is generally not between the lenses, but on the innermost side of the eyepiece, so you don't need to disassemble the eyepiece group, just take the eyepiece off and wipe the innermost side. Although it is not recommended.

Telescopes, as you use them, tend to fog up gradually, most of them.

Also, as a rule of thumb, unless you can be sure, this happens more often on prisms, not very often on eyepieces.

Didn't you pick carefully when you bought it?

This mirror is not nitrogen-filled and waterproof, so it can be taken apart. The screws on the eyepiece need to be removed. Generally, the eyepiece has 3 screws, so remove it carefully and wipe it with a special optical lens paper.

I think the grease-like stuff on the inner layer should be the rosin-like "sticky oil" of the telescope, which is sticky and not easy to dry, and is used to increase the feel of the focus wheel. If it's this kind of sticky oil, it's really hard for you to wipe it, so it's recommended to find a dealer to replace it.

Remove with a brush of dish soap.

Wipe the outside with a slightly moistened clean towel, if you are still blurry, if you can open the lens barrel, please disassemble it carefully, and then clean it. Pay attention to the order of dismantling, and take notes if necessary, so that you can pretend to be calm.