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Help - air bubbles in eyepiece lens??? (1 Viewer)

This is a nice thing with the Internet. No matter how rare things happen to you, it has very probably happened to someone else as well and now it is possible to find them easily. But no Steve, I am not an optics expert - I just have been unlucky enough to use 2 zoom and 2 fixed eyepieces with more or less "bubble problem". I would like to add that the air bubbles were not the worst optical problems with Kowa's first generation zooms ;) but they are most definitely unacceptable for a "better" scope (old Kowa scopes were great, but the zoom eyepieces were crap). I suppose this is very much about the available resources in quality control of the company. The big names in optics simply can more reliably get rid of these kinds of defects.

Thanks for the nice comments about Finland. I can tell you that going into the snow after sauna is not common among Finns - I have tried it once and I did not enjoy it at all. Your hosts probably just wanted to show off.

Maybe this should be in "Ruffled feathers" but I have no access there (?) and it was you who started these "Lappish jokes" ;)

A Lappish bird recipe:

Take a rifle and shoot a "kuikka" (= Black throated diver).
Boil the kuikka in 2 l of water - throw away water.
Boil the kuikka in 2 l of milk - throw away milk.
Boil the kuikka in 2 l of vodka - throw away kuikka.
Let it cool down and enjoy.

Ilkka
 
iporali said:
This is a nice thing with the Internet. No matter how rare things happen to you, it has very probably happened to someone else as well and now it is possible to find them easily. But no Steve, I am not an optics expert - I just have been unlucky enough to use 2 zoom and 2 fixed eyepieces with more or less "bubble problem". I would like to add that the air bubbles were not the worst optical problems with Kowa's first generation zooms ;) but they are most definitely unacceptable for a "better" scope (old Kowa scopes were great, but the zoom eyepieces were crap). I suppose this is very much about the available resources in quality control of the company. The big names in optics simply can more reliably get rid of these kinds of defects.

Thanks for the nice comments about Finland. I can tell you that going into the snow after sauna is not common among Finns - I have tried it once and I did not enjoy it at all. Your hosts probably just wanted to show off.

Maybe this should be in "Ruffled feathers" but I have no access there (?) and it was you who started these "Lappish jokes" ;)

A Lappish bird recipe:

Take a rifle and shoot a "kuikka" (= Black throated diver).
Boil the kuikka in 2 l of water - throw away water.
Boil the kuikka in 2 l of milk - throw away milk.
Boil the kuikka in 2 l of vodka - throw away kuikka.
Let it cool down and enjoy.

Ilkka
You have to join there are instructions in the Members notice board.
 
Thanks Ilkka - a great joke, too. I heard more jokes in Finland during my travels there than any other Scandinavian country.
 
mak said:
The answer to the above is NO, on all accounts.
Bubbles should not happen, but it might be found if;
The manufacturer used a glass type which is not available without very small bubbles or
The manufacturer has chosen a higher tolerance for bubbles because of the cheaper price.

I didn't word my email well. He wasn't criticising Zeiss lenses in any way at all - his point was related to all lenses in his view. He said that it was impossible to obtain a completely dust free environment and bubbles in glass were not unusual.
 
scampo said:
I didn't word my email well. He wasn't criticising Zeiss lenses in any way at all - his point was related to all lenses in his view. He said that it was impossible to obtain a completely dust free environment and bubbles in glass were not unusual.
Bubbles in glass! Depends! All glass has "bubbles" due to the processes of manufacture. The question is what tolerances are these optical companies using.Top notch companies use the lowest tolerance that can be produced commercially.

As for a dust free environment, plenty of industrial companies do have "dust free" environs, especially the electronics industry. But,as you say it's like everything else, such as taking measurements, accuracy is never possible unless you use a tolerance;)
 
scampo said:
I wonder if any of you can help. Last week, I bought an Opticron ES80 from the Infocus shop at Rutland Water. To my surprise at the time, I had to go through three scopes until I found one without a mark on the inside of its objective lens.

However, today at Rutland Water I noticed what seem to be tiny air bubbles within the lenses of the zoom eyepiece as I was birdwatching. These were especially evident when a blank sky was being looked at and look like tiny circular brighter marks with a dark perimeter within the view of the lens. There are about five altogether and they are only evident at 20x, disappearing immediately on zooming from this magnification.

As I was there, I took the scope back to Infocus but the salesman there couldn't see them yet was willing to swap the scope. But he went on to say very convincingly that all lenses have such things as it was impossible to produce a dust free perfect lens. I looked through two further Opticron scopes without eyepieces and they certainly did have a mark or two which looked like it was within the coating on the rear of the front element. Anyway, as is the way of these things, the salesman convinced me I was being over particular. But back at home the "bubbles" are indeed very clear if a lamp is looked at to give a bright plain yellow view through the scope (i.e. out of focus).

I checked my son's Swarovski and a friend's new Nikon and they are 100% clear.

Can anyone advise me on this - for instance, is the salesman generally right (he also said he had worked for Zeiss and that was the case with their lenses)? Obviously for all intents and purposes the air bubbles could be said not to matter as they are only tiny (less than 0.5mm, maybe) and can only be seen at 20x. But I am a perfectionist and feel a little let down and disappointed. Certainly in many years of photography I have never such a thing in a quality camera lens.

In every other way the Opticron is a fine scope.
Salesmen! Grim! Most but not all (Get out clause);) don't know a lot about what they are selling!

Air Bubbles:

"they are only tiny (less than 0.5mm, maybe)" TINY! What! That's not tiny in anyones' language. I've never seen any lense with flaws that size, and I've looked thro' a few! Even through a microscope.

Finally, if you have purchased a quality 'scope and you're absolutely convinced something is wrong with it. SEND it back to the manufacturer who has the ability to check within minutes whether the optic passes their quality control procedures! If it doesn't, it will be replaced with one that does. IMHO.

CravenBirds
 
So perhaps the secret is to make sure that the bubbles and dust cannot be seen through the eyepiece in an obtrusive way?
 
scampo said:
So perhaps the secret is to make sure that the bubbles and dust cannot be seen through the eyepiece in an obtrusive way?
Probably! How's dust come into the equation! Most top notch optic are sealed (nitrogen filled) The eyepiece is the MAIN thing that gives a clear image! forget the tube and the rest, As for ED's etc not that better than ordinary bloomed lenses, it's a con;)

CravenBirds
 
I'm with you and thanks for the input but do you think "con" is right (except maybe to describe the amazing extra cost charged for ED)? It might not matter most of the time but to get colour fringes around objects is surely a real enough technical issue especially if you are digiscoping, I suppose?
 
I too have wondered about the enormous cost difference between ED and non-ED and would be interested to know what the added production cost is at the factory in comparison to the buying price. I suspect it's minimal and that ED add-on cost is solely based around what we birders are prepared to pay for that little extra (or for 'the best').
Steve.
 
I tend to agree but have a feeling that the fluorite glass process sounds unusual and the amount produced would be much less so the cost would be higher.

It does seem to produce a better lens, too, and as you say, the prestige tag means that the price can be kept high - but the Opticron ES80 is half the cost of prestige scopes and is ED, even though Opticron don't advertise the fact overmuch for some reason.
 
Opticron probably don't make to big a deal of the ED glass in the ES80 as they have other scopes on the market that are not much less that don't have ED glass.

I would have to disagree that ED glass is a 'con' - yes the additional cost can be high, but you can certainly see the difference over the standard versions. Having seen normal and ED models of the same scope side by side in the field I am certainly convinced that it's worth paying out for an ED scope.
 
Depends if you are a fair weather birder or not. On a bright sunny day I don't think its necessary on a poor day....
 
But apparently the ES80 is there biggest seller by far. The "better" HR80ED is much more and weighs a ton, too - have you seen it?
 
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