Re: [Microscope] Re: Zeiss lens cleaner
- There seem to be so many lens cleaning do's and dont's that one could be
forgiven for thinking either it does not matter or they all work !
Many of the specific do's and dont's seem to relate more to the lens
surroundings and coatings than the glass itself.
And some of these do react slightly or even seriously with various cleaning
agents that are fine on bare optical glass.
Glass itself is rather tolerant to chemicals although some of the early
exotics are more easily damaged. It is more likely to be damaged by
abrasion than careful application of small amounts of chemicals. But don't
use strong Alkalis for any extended period. Short exposure to weak Ammonia
is OK on bare glass and modern coatings.
Since varnishes, plastics, sealing compounds, lens edge blackening paints,
dead black paint, lens bonding 'balsam', and coatings have changed over the
years - and different makers may have used different materials, it may be
quite important to refrain from using certain chemicals unless you confirm
they are OK.
A solvent that dissolves surrounding paint or plastic not only does damage,
but drags smears onto the lens surface which are hard to remove.
Another consideration is that solvent may wick into gaps and joints and be
very hard to remove. And it sits there working on the plastics, sealants,
and balsam lens cements.
SO - I would take many recommendations relating to modern lens cleaning with
caution. For example - most modern lens coatings are extremely hardy and
will take a lot of scrubbing and strong chemicals. Some seem more hardy
than the glass underlay. Yet one of the earliest coatings was Calcium
Fluoride which is fragile. Some actual lenses were also made of CaF.
Later, Magnesium Fluoride was very common. It remains in use today for the
run of the mill lenses. Some of its application was poor and one has to
It is interesting that the recently commented on ROR (Residual Oil Remover)
seems to have a composition of
Ammonia 0.8 %
Sodium Chloride 0.8 %
IsoPropyl Alcohol 4.3 %
Liquid Soap 9 %
Distilled Water 85%
Which to me is very strange and I find it hard to believe.
Why use distilled water then add NaCl which would leave a residue !
Or was it really intended for contact lenses ?????
One sometimes sees dire warnings against Ammonia. A small amount of weak
Ammonia is excellent for removing oil and grease smears. And it seems to
do no hard to modern multicoats and bare optical glass. But it would take
off CaF coatings very quickly and possibly the MgF ones as well if
A very widely used lens cleaner is Distilled water, 5 to 10 % IPA, a few
drops of Photoflow (memories - a detergent which seems to leave no residue)
and a small dash of Ammonia if you like.
An almost refreshing page on cleaning Televue products is at
But this may not be well suited to some older microscopes because Televue
coatings are modern and the best.
Windex, by the way, seems to now mean many different things. It once was
close to the brew given above.
- Bad form to reply to ones own emails but
>Should have mentioned for anyone wanting to trace this down most of the web
> On bare glass, one readily available agent that has been used by people
> making photographic plates (like making the emulsion and coating the
> is NapiSan. Or is it NappySan ?? The glass is simply left to soak in a
> Because of the coating the surface needs to be very clean and it seems to
> work. Somewhere there is web material on this.
> Also labelled as a Soaking and Cleaning agent in Supermarkets possibly to
> bypass the above trade name.
> Anyway, it contains a high percentage of Sodium PerCarbonate which is a
> strong oxidizer.
material was about making Plates for Holography.