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

Well the 8x can be called a wide angle bino since its AFoV seems to be ~67° vs a more pedestrian (but still nice) ~60° for the 7x. Unless you want the brighter exit pupil of the 7x then I would say the 8x would be great. BUT, few wide angle bins are sharp edge to edge. Some find that bothersome. FWIW, the 10x seems to have an AFoV of ~70° making it an ultrawide.

Oh, I think they use silver on the prisms.

cheers,
Rick
 
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Definitely silver prisms.

From what I remember originally reading, the prisms were designed primarily with the 8x42 in mind (hence the impressive true and apparent field of views for an 8x42). The 7x42 utilizes the same exact design hence the same field of view on both models (411 feet...7.8 degrees). Whether or not you believe that......but it was what I had originally read.

I have compared both extensively and preferred the 8x42.
 
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its impressive that a silver prism bino is as bright as a dielectric coated one. im trying ot figure out how the 7x and 8x can have the same FOV. i emailed meopta a few days ago on some questions and havent heard back


frank why did u prefer thr 8x? i have read you sing the 7x's praises
 
308CAL said:
its impressive that a silver prism bino is as bright as a dielectric coated one. im trying ot figure out how the 7x and 8x can have the same FOV. i emailed meopta a few days ago on some questions and havent heard back


frank why did u prefer thr 8x? i have read you sing the 7x's praises
Click to expand...

308,

You might have me confused with another Meopta user. The 7x is a solid 7x that should be compared with more expensive glass. It was never my favorite of the Meostar configurations though. Someone else on here does use them and is very impressed with them though if I remember correctly.

The reasons I prefer the 8x are fairly simple. I did not really notice much of a difference in optical performance between the 7x and 8x except for the significantly larger apparent field of view of the 8x's. The larger exit pupil and the increased depth of field in the 7x just weren't as noticeable to me as the larger apparent field of the 8x was. It really is quite noticeable and comparable to the original 8.5x42 EL in that regard. The image representation just looks "big" because you see so little of the black outside the field stop.

One answer to your question might be the specific prism design that Meopta uses in their binoculars. It is not the conventional Schmidt-Pechan if I remember some of the information surrounding it correctly. I have seen it called a half-pentagonal/Schmidt and something else that I honestly cannot place at the moment.

The other answer may very well be the coating combination that they utilize. I know the comparisons to Swarovski are often common place. In the area of coatings and low light performance I think they compare as well. The Meoptas really do "come into their own" in low light condtions. I remember several times when I compared the 8x42 Meostar with the 7x42 FL and thought that the Meostar performed just as well as the FL as light levels started to drop.

Hope this helps.
 
Hi 308,

I have the Meopta 7x that Frank mentioned. If you viewed the 7x and 8x separately you might think their qualities are similar. Comparing them side-by-side is a different thing completely.

To my eyes – compared side by side with 8's – I see more FOV in the 7x. The 8x FOV fits inside the 7x. Not sure what the numbers say for apparent FOV but this is the case.

Depth of field – 7x is much better than the 8x. If I viewed at separate times I might not notice... but compared together? It's easy to see.

Ease of view – 7x wins for me hands down. Larger exit pupil is easier on my eyes. The 8x has less side-to-side forgiveness.

Eye relief – 7x has a boat load. I have glasses. 8x is very good and I can see the complete field.

Steadiness – 7x wins here. For obvious reasons.

Field flatness – Meopta is known for their excellent field flatness. 7x is better and more noticeable in the edges than the 8. But splitting hairs here.

Edge performance – This is again where Meopta shines. Sharp to the edges. Both excellent. 7x a little better (very little).

7x vs 8x magnification debate. Never cared about this. 7x to 8x is not a big deal. Anyone who says it makes a big difference either has not spent time behind a good 7x or is worried about a number or that they might miss something because of that number.

I bought the 7x because I got a demo at a very good price (from Meopta) I had compared 7x and 8x and the magnification was not a big deal. The benefits I got in the 7x became apparent only over usage and time. But, they are real differences.

Kind of like wine. A sip will only tell you so much. Experience will reveal its nuances.

Depends on what you want.

Cheers
 
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A perfect example of two folks looking at the same two binoculars and coming up with two different opinions. My experiences did not reflect Pete's but that is the beauty of having so many configurations to choose from.

For what it is worth I think the 8x32 version is actually my preferred version at this point...with the 8x42s just a little behind.
 
I'll drink to that!

Frank... if you lived with the 7's you'd learn to love them. You're always
chasing after the young sexy bins!

Cheers
 
FrankD said:
One answer to your question might be the specific prism design that Meopta uses in their binoculars. It is not the conventional Schmidt-Pechan if I remember some of the information surrounding it correctly. I have seen it called a half-pentagonal/Schmidt and something else that I honestly cannot place at the moment.
Click to expand...

I'd noticed that too and put it down to slightly odd translation from the Czech optical jargon as what we call a Schmidt-Pechan prism is really a semi-pentaprism ("half-pentagonal") with a Schmidt-Pechan prism on top of it.

http://en.wikipedia.org/wiki/Schmidt-Pechan_prism

The original prism by Pechan had a mirrored "flat roof" and didn't do image reversion.

http://www.tpub.com/content/firetrucksandequipment/TM-9-254/img/TM-9-254_271_2.jpg

It was Schmidt who added a "peaked roof" to do reversion). Now they're known as Pechan, Schmidt-Pechan (I think the latter especially in German speaking counties!). I suspect the Czech's may just use a slightly different term.

A cutaway from the 2009 catalog shows it looks as one would expect

http://www.meopta.com/download/sport-ang-final-pdf-4439.pdf

I really don't think they use anything odd ...
 
Too bad Meopta sports optics are not available in Japan. Only thing I could find is some collector camera products. They seem to have some interesting binos and the digiscoping kit for the spotter is really unique.

cheers,
Rick
 
Buster,

The Cabela Euro bins are identical except for the name badge and rubber armor (the armor is minus the dimples).

Cheers
 
Schmidt-Pechan can be configured in different ways. Light can transit in either direction and the roof can be installed in either the Schmidt or the semi-pentaprism part. Meopta uses the less common arrangement of placing the Schmidt prism first, followed by a semi-pentaprism with roof. The Nikon LX-L and Swarovski EL are also done that way. Zeiss, Leica, Swarovski SLC and, I think, most others place the semi-pentaprism first followed by a Schmidt with roof.


Edit: Sorry, I knew what I meant, but I wrote down the examples exactly backwards. Meopta, Nikon and Swarovski EL place the semi-pentaprism first in the light path with the Schmidt (with roof) following. Zeiss, Leica and Swarovski SLC place the Schmidt prism first with the semi-pentaprism (with roof) following. The mirror coated surface is always in the prism without the roof.
 
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I spoke to meopta today & they said the 7x42 does have a larger FOV than the 8x42. The website will reflect the changes on Monday.
 
henry link said:
Schmidt-Pechan can be configured in different ways. Light can transit from either direction and the roof can be installed in either the Schmidt or the semi-pentaprism part. Meopta uses the less common arrangement of placing the Schmidt prism first, followed by a semi-pentaprism with roof. The Nikon LX-L and Swarovski EL are also done that way. Zeiss, Leica, Swarovski SLC and, I think, most others place the semi-pentaprism first followed by a Schmidt with roof.
Click to expand...

Light can go through the prism in either direction so an SP can be installed either way around.

So you are saying that some manufacturers interchange the roof in the Schmidt (making it a Pechan ... a flat roofed Schmidt) and the reflective surface in the semi-pentaprism?

I presume it changes the shape of the prism assembly and (optically) nothing else.

As to the original question ... it's still the same SP configuration with two surfaces interchanged and an interesting translation.
 
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I just edited my earlier post because I realized the examples were backwards. I think it is easiest to think of the Schmidt-Pechan as a Schmidt and a semi-pentaprism with an airspace in between. The order doesn't matter and the roof can be placed in either prism.

In every example I've seen the roof is in the "back" prism (closest to the eyepiece), probably because it's cheaper and easier to make it small. The 90 degree reflections between the roof faces allow for TIR in the prism that contains the roof, so when the roof is in the Schmidt prism one surface of the semi-pentaprism has to be silvered. When the roof is in the semi-pentaprism one surface of the Schmidt has to be silvered.
 
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We agree then, Henry, and your revised scheme matches to cutaway of the Meopta too. ;)

So of the four potential SP combos (roof position x prism orientation) do manufacturers only use two of them i.e. the roof is always on the prism closest to the eyepiece? Because the light cone is smallest there, perhaps?

One thing they don't point out on the cutaway (which I though they would) is the field flattening lens just in front of the prism.

The new FOV numbers for the 7x: does that indicate an error that's been there for some time (though not a copy and paste error ... the numbers are a little different). Or a small design change? I'm also thinking of FrankD's comments about a replacement Meopta being less "yellow" than the original.

It is interesting to speculate on a slightly redesigned Meopta Meostar (a B2?) with dielectric coating and fluorophosphate glass in the objectives. From FrankD's comments it would seem that would give the Top Four bins a run for their money for perhaps rather less money especially if the goal is flatter and low astigmatism field (which seems to be the direction Nikon EDG and the new Swaro EL are heading).

Perhaps in a couple more years.
 
yes the guy I spoke with didnt seem like the brightest guy in the world. I dont know if it was design change or a misprint the last 4 years????
 
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