Humidity & Fluoride lens

[Tropo-Bob]

I am considering buy a Tak fluoride refractor as a retirement present to myself. However, humidity is normally around 83% here in the summer, so I am worried that this may affect the lens over time.

I am a pretty much a wimp in summer and will not take my best scopes outside in such conditions. Nevertheless, the reality is that humidity will still be high from time to time in my house. Though again, I am a wimp and the air con is on quite frequently!

Any opinions of how well a fluoride lens will cope (or not cope) with high humidity will be appreciated.

[Atmos]

Humidity is only an issue in that is causes dew and that can be mitegated on the objective with a few strap. Unless there is something else you're worried about with the humidity?

[Tropo-Bob]

Thanks Colin,

That makes sense. I may have been overthinking by worrying that high humidity as distinct from water liquid could also damage the lens.

There is mould etc of course, but this is common to all refractors.

[Kunama]

I think the real danger is mould/fungal infestation in your climate. The fluorite lenses are fully coated but like any lens needs to be kept out of harm's way by storing with desiccant in a good quality case, always throughly dry prior to storage.

I have a sachet of desiccant velcroed to the inside of the objective cap and another in the focuser cap as well as three big bags of desiccant in the Pelican case with the scope at all times.

[LewisM]

the Fluorite Solubility issue is just pure hype and BS promulgated by manufacturers NOT using fluorite. You literally need to soak fluorite in water for DECADES for it to dissolve even by a tiny percentage. I have owned MANY Tak Fluorites and I lived in near constant 85% humidity - not a single issue.

Tak has gone back to fluorite yet again after a hiatus making ED glass refactors, and TEC in the US is going to be making 140mm refactors in fluorite.

And just so you know, Willaim Optics refractors have never used fluorite. That was a BAD marketing ploy that cost them dearly - there are still many people who do not know that the "Fluorostar" and some other WO do NOT have fluorite lenses (they have FPL, which is NOT CaF2). Tak on the other hand are synthetic, lab-grown pure CaF2.

BTW, it is fluorite. Fluoride is in your toothpaste, and conspiracy nuts will tell you not to use it cause it'll turn you into an anti-fluoride nut. :)

[multiweb]

Really? I thought that's why Matt's dog had whiter teeth?:question:

[LewisM]

No, Matt's objective is yakky ED - not fluorite perfectiom.

Matt's dog is a little Toe-ey though :)

[Visionary]

Thanks for the "heads-up" re: WO!

[LewisM]

No problem - the sooner that old advertising deception dies, the better. There is a full post discussing it written by the iStar owner/lens grinder on his site.

W.O was forced to retract their deceptive advertising, and subtly reworded it.

Yes, FPL glasses are fluorite enriched, but they are NOT fluorite by any stretch of anyone's imagination. Fluorite have NO bubbles, whereas even the very finest FPL's will.

As a side note, O'Hara has now dropped FPL53, to be replaced by the as-yet fairly unknown quality of FPL55. this is one of the reasons Yuri is going to fluorite in the new 140 version. Roland Christen at AP believes he has enough FPL53 to last a while.