Refractors - Objective lens cleaning?

[Planetesimal]

I assume something like Baader Wonder Fluid can be used to clean the front of the objective lens on my 4" frac? I find it tends to pick up dust (not all of which can be removed with a blower) while it's still damp with dew...

[Peter Drew]

Baader Wonder Fluid is fine for this purpose. Be sure to apply the fluid to the cloth first rather than the objective. Always a good idea to blow or brush off any loose dust if possible when the objective is perfectly dry.

[AndyH]

Always a good idea to blow or brush off any loose dust if possible when the objective is perfectly dry.

Never has a truer and more important statement been uttered

That tiny spot/lump of dust could be a tiny piece of stone-like material, just waiting for you to swirl it all over your lovely lens coating

Odds are against it perhaps, but better safe than sorry ?

[LeeB]

The purists might hate me but after the puffer I use a baader cloth , but use solution 30 spray followed by a breath if need be, and it never leaves a mark. I have even checked under a microscope for any small scratches but could'nt find any even on one lens that must have been cleaned 50 plus times. If a new purchase has a really dirty lens I remove and clean like a newt mirror and rinse with distilled water. (alway note orientations and make marks on the edge that will not come off.)

[E621Keith]

First use a blower to blow away as much debris as possible.

Then spray Baader fluid on lens tissue and wipe gently. Always wipe in a straight line and never in circle. Never wipe using the same part of the lens tissue twice and always use a new clean area of the tissue. Ideally use a new sheet every wipe, but that can be quite expensive.

I prefer thick lens tissue (e.g. PEC Pad or HCL thick lens tissue) over microfibre cloth. While new Baader cloth is nice, once it has been used, dirt can be trapped in the cloth from previous clean. /Those dirt may scratch your lens in subsequent cleaning process. It's not really economical to buy a new cloth every time you clean your optics, so good lens tissue is the next best option. I use my Baader cloth on semi-expendable items only (e.g. protective filters)

[Planetesimal]

Thanks all!

Looks like I need to get a dust blower to start with... I hadn't thought of using lens tissue, good idea!

One thing I've found when looking at the front of the lens element on my TAL, is that it's actually quite hard to see the physical surface of the lens. It sort of looks concave, even though I know the "crown" should be convex (I'm sure this must be an optical illusion)! Has anyone ever found the need to clean the other "inner" side of the lens element? I can't really tell whether mine's clean, although it does seem to get fogged up on the inside of the lens as well as the outside, which leaves a sort of "swirly" pattern if you shine a light on it...

[Steve Jackson]

Can i suggest a Giotto's Super Rocket Air Blower, it wasn't cheap but it's a fine piece of kit which has done a good job over the years.

It's pretty big so fits snugly in your hand and supply's a good puff of air.

I use it for photography but has been great with my scope too, i would be lost without it.

[Planetesimal]

Can i suggest a Giotto's Super Rocket Air Blower, it wasn't cheap but it's a fine piece of kit which has done a good job over the years.

It's pretty big so fits snugly in your hand and supply's a good puff of air.

I use it for photography but has been great with my scope too, i would be lost without it.

Something like this?

http://www.amazon.co.uk/Giottos-GTAA1900-Rocket-Air-Blower/dp/B00017LSPI

[Steve Jackson]

That's the exact one!

Not too sure what others are available but this one does me just fine.

Don't take my word on it, read a few reviews on it and decide. I'm no expert by a long shot.

[Planetesimal]

Thanks Steve!

[TonyD]

This may sound stupid, but what about a powerful hair dryer blowing cold air?

[E621Keith]

This may sound stupid, but what about a powerful hair dryer blowing cold air?

I have a powerful hair dryer, it helps a bit, but no where as effective as a big rubber hand blower.

A hair dryer generate quite a lot of air flow, but not much pressure so it's not as effective in dislodging dusts. Aerosol air duster is the most effective in removing dust, but they have some potentially very nasty side effect.

[TonyD]

I have a powerful hair dryer, it helps a bit, but no where as effective as a big rubber hand blower.

A hair dryer generate quite a lot of air flow, but not much pressure so it's not as effective in dislodging dusts. Aerosol air duster is the most effective in removing dust, but they have some potentially very nasty side effect.

Yes I wouldn't use anything with a propellant.

[allcart]

I use Eclipse fluid for cleaning the sensors on my dslr's. would this be ok for cleaning the objective on my Tal.

[E621Keith]

I use Eclipse fluid for cleaning the sensors on my dslr's. would this be ok for cleaning the objective on my Tal.

Best to use Baader fluid. Eclipse is more aggressive and it dissolved the coating on my old Celestron X-cel eyepiece. It is also less effective in removing fungus. Having said that, Eclipse leaves less residue than Baader and I've used it to clean many scopes (including Celestron SCT corrector plate) with no problem. I think it's fine on most scopes, but you should know there is a risk.

[allcart]

I did wonder if it might effect the coatings so I thought I would ask first. There are no coatings on the sensor glass that I know off so for sensors its safe enough. I'd better play safe and get some wonder fluid.