Keep your eyepieces, telescope lenses, corrector plates, camera lenses and filters clean this during this observing season with Baader’s Optical Wonder fluid and microfibre cloth.

Baader Optical Wonder™ Cleaning Fluid
Baader Planetarium’s FineOptical Cleaning Fluid is a very effective cleaning solution that is less aggressive than other cleaning solutions, but is extremely effective at removing dirt, oils (pollen and fat) and finger prints marks along with their associated acidic residue. The solution dries up without leaving any cleaning marks and also forms a protective layer against bacteria and fungi that can attack and degrade optics and their special coatings. You can use the cleaning fluid on your eyepieces, refractor objective lenses, catadioptric (SCT/Maksutov) corrector plates, DSLR camera lenses and even on your daily/reading glasses too.

Optical Wonder™ Cloth
To go hand-in-hand with the Optical Wonder Cleaning Fluid is Baader Planetarium’s Optical Wonder Cloth. This is a large (25cmx25cm / 10”x10”) super micro-fibre cleaning cloth that is very soft and will not scratch your optical surface(s).
Instructions are supplied with the cleaning fluid on its use, but prior to any cleaning we recommend that optical surfaces are first inspected to see if they really require cleaning. A small amount of dust or dirt will not affect your viewing. For optics that are dirty, dirt can act like sandpaper when rubbed, so can scratch your optics. We therefore recommend the use of an air blower (rather than canned compressed air dusters as these can leave a residue on the optics) to remove as much dust/dirt as possible prior to cleaning. When cleaning apply very little pressure.
Mr Thomas Baader has written a very good guide on cleaning optics with the Optical Wonder fluid. You can read it here.
Finally a tip – there is a general rule of thumb with optics – if its not dirty then don’t clean it. As mentioned above a small amount of dust is not going to affect your views and “over cleaning” increases the probability of scratching your optics.