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Does MEOPTA use Dielectric or Silver mirror on the prism? (1 Viewer)

Back to the original subject. Silver is very easily tarnished. Even with a nitrogen-filled binocular there would be some leakage over a period of several years resulting in an ongoing reduction in light throughput due to the silver tarnishing. I would be concerned that a binocular with an excellent light throughput (say average of 92%) would turn out to be maybe 85% after 5 years and, maybe 75% after 10 years. The change would be so gradual that it would be difficult to notice.
You would simply have a $150.00 binocular (with respect to glare and light throughput) after a few years.

Obviously, I am just guessing, but is this type of thing a concern for anyone else?

Don Clark
 
The silver is protected by a coating on the back, much like an ordinary mirror, so it should retain high reflectivity. The reflective side is protected by the glass, unlike the silvering on telescope mirrors, which are exposed.
Note that modern reflectors have protective mirror coatings as well, but data on how well they retain reflectivity is not known to me.
 
Don,

I don't think the deterioration will be quite that rapid. After all, unlike a first surface mirror the reflective side of the silver is deposited on glass and I'm guessing there is an opaque protective coating on the exposed side. And of course if the binocular is sealed and nitrogen purged the seals have to fail first. Still, eventually all these silver coated prisms probably will tarnish, although it may take many decades. I've read about early Leitz Trinovids (not air-tight) tarnishing to the point of becoming largely useless after 30-40 years. My understanding is that Leica no longer has the prisms to fix them. Even when the prisms were still available it was an $800 repair.

Henry

Edit: I see etudiant made most of the same points as I was writing. My guess is that silver coated roof prism binoculars will be OK for a long time, but might not make good family heirlooms.
 
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Deterioration from tarnishing or oxidation is not supposed to be a problem, even for first surface dielectric mirrors exposed directly to air. Dielectric coatings are thin film oxides similar to anti-reflection coatings, not metal.
 
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The guy from Meopta will probably continue to say that until the day Meopta changes to dielectric coating, which will certainly happen eventually. It is true that dielectric coating can be done poorly and presumably cheaply at the same time.

See the graph below from the Nikon Vision Co. website which shows the reflectivity of various coating materials. Besides higher and more linear reflectivity, properly done dielectric coating also has much lower light scatter than metallic coatings.
 

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oleaf said:
Frank,

For me the 8x EII didn't even seem like an 8x as the field was so big. Seemed like a 6 or 7x...

Cheers
Click to expand...

Oleaf,

I perceive a difference in image scale btwn the 8x30 EII vs. 8x32 SE, and I suspect, as you do, that it's an illusion created by the wider FOV. The EII looks like 7x next to the SE.

When I compare the EII to the 8x32 LX, the EII's image looks even smaller, like 6x, because of the LX's roof illusion of larger image scale.

"In my humble opinion, we've become involved in Einstein's time-space continuum theory.

Relatively speaking, that is."

- Ringo, in "Yellow Submarine"
 
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falcondude said:
until they change to dielectric coating and raise the price by $300.;)
Click to expand...

Falcondude,

From a marketing POV, it matters less how much "better" a new model actually is, than how companies are able to create the perception of it appearing better and therefore a desire in the consumer for the "cachet" in obtaining the "latest and greatest" at whatever the cost.

If the leading brands have it, then other companies nipping at their heels better have the "newer and improved" technology too, because if not, consumers are going to perceive their product line as lagging behind or even "inferior".

If binocular optics never got better than the 8x SE, EII, and LX, I wouldn't fret.

Sure, I would like ED glass for even more zing and better CA control, and I'd like one or two full sized 8x models to compliment my middies (the LX does have an 8x full sized model, but it's devoid of pincushion).

There's no question that updated coatings do improve the view, but from what I've seen lately in doing comparisons of some of the latest roofs with my older porros and from reading comments about new roofs on BF and elsewhere, we seem to be getting to the point of diminishing returns whereby users are paying disproportionally more and more for incremental improvements in the "newer and improved" models.

OTOH, if they weren't doing this, we'd all be posting to the Swift History threads, because what else would there be to talk about but classic porros? :)

If we really want to move ahead in optics, we need "punctuated equilibrium" rather than costly "gradualism".

But, like I do with computer software, I'd lag behind and wait until the "bugs" were worked out and let more deep pocketed pioneers buy the new technology until companies have recovered their R & D costs or until that new technology is available on the used or discount market (I would have scooped up those $1,100 8x42 EDGs if I were flush), or until it finally trickles down to more reasonably priced models.

But I have seen the future, and it is based on 0s and 1s, not dielectric coatings:

http://www.holgermerlitz.de/digitalbino.html

B'rockster
 
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good points.... im not sure how much better standard technology will get. THe Meoptas are great and the EL's are a little better but at a HUGE cost...then NEW EL's will be WAYm ore than the current EL's for a small improvement...etc
 
Brocknroller,

The EII's do indeed warp our idea of space. The view is so wide it causes the fabric of perception to collapse upon itself – rendering a smaller than 8x view.

Unlike the EL's which warp our perception of value... causing a collapse of checking account!

But, since you're a Klingon... you already knew this.

Cheers
 
Henry,

I guess we could all debate the Silver vs Dielectric coatings... but Meoptas are as bright
at every format as the top sellers... so they must know something.

From what I understand they are a leader in optical coatings in Europe.

Cheers
 
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oleaf,

I can't say anything about the brightness of Meopta binoculars since I haven't examined them closely or compared them directly to other binoculars, but whatever their light transmission is now with sllver coating should be improved by at least 5% with dielectric coating.

Henry
 
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Brock you really do have a rude habit of hijacking threads and taking them in a completely different direction. From our emails I know you are a nice guy that enjoys writing about binoculars and I understand it can be hard to break "flow of concience" thing, like we are all just sitting around the campfire chatting, but you really should start a new thread when you get the urge to go off topic. Sometimes it is nice just to have the facts without weeding thru pages of idle, uniformed/unconfirmed speculation that permeates so many of these discussions. My apologies to the members and Brock for this uncharacteristic attack, but I just could no longer hold back.

thx,
Rick
 
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RJM said:
Brock you really do have a rude habit of hijacking threads and taking them in a completely different direction. From our emails I know you are a nice guy that enjoys writing about binoculars and I understand it can be hard to break "flow of concience" thing, like we are all just sitting around the campfire chatting, but you really should start a new thread when you get the urge to go off topic. Sometimes it is nice just to have the facts without weeding thru pages of idle, uniformed/unconfirmed speculation that permeates so many of these discussions. My apologies to the members and Brock for this uncharacteristic attack, but I just could no longer hold back.

thx,
Rick
Click to expand...

Relax, Rick, Brock did refer back to the original intention of this thread which was about silver vs. dielectric coatings. My experience would lead me to say that a company that does an excellent job may deliver a superior product using silver prism coatings, vs. some others using subpar dielectric coatings.

The total of what you view through and how the many features are integrated into a quality optic are what counts. Witness the growing pains with some of the Chinese products ( wanna bees) vs. some of the proven, such as Meopta talked about here.
 
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RJM said:
Brock you really do have a rude habit of hijacking threads and taking them in a completely different direction. From our emails I know you are a nice guy that enjoys writing about binoculars and I understand it can be hard to break "flow of concience" thing, like we are all just sitting around the campfire chatting, but you really should start a new thread when you get the urge to go off topic. Sometimes it is nice just to have the facts without weeding thru pages of idle, uniformed/unconfirmed speculation that permeates so many of these discussions. My apologies to the members and Brock for this uncharacteristic attack, but I just could no longer hold back.

thx,
Rick
Click to expand...

Rick,

After 54, count 'em, posts on this thread about dielectric coatings on the Meopta, I thought perhaps we had exhausted the technical discussion and that it was time to get a larger perspective about this issue rather than to continue to nitpick on Meopta dielectric coatings ad absurdum (particularly since they don't actually exist!).

I had originally posed these questions in another thread, but this was the first time an optics expert was on the same thread about incremental improvements in roof bins as I was, so I thought it would be an opportune time to get his opinion, and rather than PM him, to ask on the thread so that others could read his answers too.

However, if your preference is for strict adherence to the OP, "facts" to the thousandth arcseconds, without "weeding through pages of idle, uniformed/unconfirmed speculation" (read: creative thinking), and dry, humorously writing (except for posts by Kenny J., who you might find equally "rude" with his meandering and "idle chitchat"), check out Cloudy Nights bin forum! You will love it there.

Sorry if I got your feathers ruffled, Rick.

In the interest of peaceful interplanetary relations, I will repost my query on a new thread.
 
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At the risk of wading into already troubled waters I'll have to join Rick in objecting to threads being used as springboards for wildly irrelevant wanderings. There must be some happy medium between the schoolmarmish knuckle rapping practiced at CN and allowing binocular threads to morph into cajun cooking by way of Klingon linguistics. If a thread is exhausted it should just end.
 
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