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Or is it Mr. Rooney?
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New = Better? (binoculars)
- Thread starter moribundman
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Originally Posted By: moribundman
..... I already said I was pretty sure it was an alignment issue.
Based on your expertise in optics?
Originally Posted By: moribundman
Second, you got it wrong. Both of these Pentax binocs use inverted porro prisms (BAK-4), they do not have roof prisms.
BAK-4 has literally nothing to do with porro prism versus roof prism.
BAK-4 refers to the quality of the glass and reflective surfaces.
Roof prisms are the ones without an angle to them, while porro prisms are the ones with a bend in them:
http://www.just-binoculars.com/Images/prism_types2.jpg
All the Pentax 8x24 and 8x25 binoculars are roof prisms.
The porro prism Pentaxes for the last 20 years or so in 8 power have all been 8x40.
Originally Posted By: moribundman
Third, it is roof prisms that have the inherent issues not only with the quality of prisms, which require phase correction, but which also require super accurate alignment due to how the optical path is "folded."
Both roof prisms and porro prisms fold the light path and require precision alignment.
As you can see from the diagram above, the number of folds and surfaces in a roof prism exceed those in a porro prism.
Since you loose about 5% of the light with each surface, not only alignment but the lens coatings become critical in a roof prism. Roof prism binoculars, all things being equal, always underperform a porro prism due to the laws of physics.
Originally Posted By: moribundman
An inexpensive roof prism design is always optically inferior to a porro prism design, but the latter can, at high cost, achieve near identical performance. Porro prism designs do not got out of alignment as easily as do roof prism designs.
There are inherent differences in roof prisms from porro prisms that cannot be overcome, and these are the result of the laws of physics. An 8x25 optic cannot perform in low light as well as an 8x40 optic, and an 8x40 roof prism is basically an impossibility.
Take a look at the diagram. Multiply the loss of image at each surface by the number of surfaces and you can see the problem.
That does not mean that - with careful design and assembly and state of the art coatings - a roof prism binocular cannot be high-performance. But dollar for dollar the porro prism - at the expense of weight and bulk - will always outperform it.
Originally Posted By: moribundman
Don't tell me about price point, without knowing the purpose for which I need small binocs.
That wasn't in the discussion.
You were kvetching about performance.
Originally Posted By: moribundman
You simply do not know my requirements in this case.*
You didn't mention requirements. You mentioned performance.
As anyone can see, the roof prisms are neat and compact.
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..... I already said I was pretty sure it was an alignment issue.
Based on your expertise in optics?
Originally Posted By: moribundman
Second, you got it wrong. Both of these Pentax binocs use inverted porro prisms (BAK-4), they do not have roof prisms.
BAK-4 has literally nothing to do with porro prism versus roof prism.
BAK-4 refers to the quality of the glass and reflective surfaces.
Roof prisms are the ones without an angle to them, while porro prisms are the ones with a bend in them:
http://www.just-binoculars.com/Images/prism_types2.jpg
All the Pentax 8x24 and 8x25 binoculars are roof prisms.
The porro prism Pentaxes for the last 20 years or so in 8 power have all been 8x40.
Originally Posted By: moribundman
Third, it is roof prisms that have the inherent issues not only with the quality of prisms, which require phase correction, but which also require super accurate alignment due to how the optical path is "folded."
Both roof prisms and porro prisms fold the light path and require precision alignment.
As you can see from the diagram above, the number of folds and surfaces in a roof prism exceed those in a porro prism.
Since you loose about 5% of the light with each surface, not only alignment but the lens coatings become critical in a roof prism. Roof prism binoculars, all things being equal, always underperform a porro prism due to the laws of physics.
Originally Posted By: moribundman
An inexpensive roof prism design is always optically inferior to a porro prism design, but the latter can, at high cost, achieve near identical performance. Porro prism designs do not got out of alignment as easily as do roof prism designs.
There are inherent differences in roof prisms from porro prisms that cannot be overcome, and these are the result of the laws of physics. An 8x25 optic cannot perform in low light as well as an 8x40 optic, and an 8x40 roof prism is basically an impossibility.
Take a look at the diagram. Multiply the loss of image at each surface by the number of surfaces and you can see the problem.
That does not mean that - with careful design and assembly and state of the art coatings - a roof prism binocular cannot be high-performance. But dollar for dollar the porro prism - at the expense of weight and bulk - will always outperform it.
Originally Posted By: moribundman
Don't tell me about price point, without knowing the purpose for which I need small binocs.
That wasn't in the discussion.
You were kvetching about performance.
Originally Posted By: moribundman
You simply do not know my requirements in this case.*
You didn't mention requirements. You mentioned performance.
As anyone can see, the roof prisms are neat and compact.
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Originally Posted By: moribundman
Or is it Mr. Rooney?
Bad attitudes result in unpleasant retorts.
Even if you're moribund.
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Or is it Mr. Rooney?
Bad attitudes result in unpleasant retorts.
Even if you're moribund.
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Originally Posted By: Rolf
Bad attitudes result in unpleasant retorts.
Oh, planning to do more backstabbing? There is something Dennis Hopper says in Waterworld that applies to you.
I love it when you waste time writing lots of stuff that I can just skip.
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PS: the mouse that roared
Bad attitudes result in unpleasant retorts.
Oh, planning to do more backstabbing? There is something Dennis Hopper says in Waterworld that applies to you.
I love it when you waste time writing lots of stuff that I can just skip.
.
PS: the mouse that roared
Originally Posted By: moribundman
Oh, planning to do more backstabbing?
You have bad attitude.
Trust me .... I am unimpressed.
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Oh, planning to do more backstabbing?
You have bad attitude.
Trust me .... I am unimpressed.
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Last edited:
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I'm not impressed either, Mickey.
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Originally Posted By: moribundman
I'm not impressed either, Mickey.
My name is not Mickey, morbidman.
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I'm not impressed either, Mickey.
My name is not Mickey, morbidman.
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Mine isn't morbidman or moribundman, Mickey. I can call you Michelle, if you prefer.
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PS: I love that extra space thing!
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PS: I love that extra space thing!
Originally Posted By: moribundman
I can call you Michelle, if you prefer.
You do seem to tend that way.
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I can call you Michelle, if you prefer.
You do seem to tend that way.
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Well, you do seem rather blonde.
By the way, I was comparing the performance of the older 8x24 with the newer 8x25 binocs, since you seem to have missed that tidbit. So there's no need to drag in binocs with vastly different specs for comparison.
So Michelle, don't you have some oil thread to which you must tend? I hear they are missing you already!
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By the way, I was comparing the performance of the older 8x24 with the newer 8x25 binocs, since you seem to have missed that tidbit. So there's no need to drag in binocs with vastly different specs for comparison.
So Michelle, don't you have some oil thread to which you must tend? I hear they are missing you already!
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Originally Posted By: moribundman
Well, you do seem rather blonde.
Speaking of blonde .... let me add "optics" to the topics you've demonstrated you know next to nothing about.
If you want excellent optics and small size, go with the 6x30 or 8x30 military optics, or civilian copies thereof.
http://www.holgermerlitz.de/kronos6x30.html
Buying cheap roof prism binoculars and complaining about them brands you a ninny.
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Well, you do seem rather blonde.
Speaking of blonde .... let me add "optics" to the topics you've demonstrated you know next to nothing about.
If you want excellent optics and small size, go with the 6x30 or 8x30 military optics, or civilian copies thereof.
http://www.holgermerlitz.de/kronos6x30.html
Buying cheap roof prism binoculars and complaining about them brands you a ninny.
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You take the cake when it comes to ignorance. The binocs to which you linked are PORRO prism binoculars. They are not roof prism binoculars.
I never buy roof prism binoculars. I buy either regular porro prism designs like my Steiner, or inverse porro designs like the Pentax, which you erroneously believe to have roof prisms. You are just plain wrong.
You may want to inform yourself properly. Then you might get it not all completely wrong.
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PS: I don't buy Russian stuff.
I never buy roof prism binoculars. I buy either regular porro prism designs like my Steiner, or inverse porro designs like the Pentax, which you erroneously believe to have roof prisms. You are just plain wrong.
You may want to inform yourself properly. Then you might get it not all completely wrong.
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PS: I don't buy Russian stuff.
Originally Posted By: moribundman
You take the cake when it comes to ignorance. The binocs to which you linked are PORRO prism binoculars. They are not roof prism binoculars.
I've been successful. You now apparently know that there are both porro and roof prisms.
Now we can move to Galileo binoculars.
Originally Posted By: moribundman
I never buy roof prism binoculars.
If you bought Pentax 8x24 and/or 8x25 binoculars, you bought roof prisms. Period.
Originally Posted By: moribundman
You may want to inform yourself properly.
Thanks for the laughs.
I look forward to your next syllable.
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You take the cake when it comes to ignorance. The binocs to which you linked are PORRO prism binoculars. They are not roof prism binoculars.
I've been successful. You now apparently know that there are both porro and roof prisms.
Now we can move to Galileo binoculars.
Originally Posted By: moribundman
I never buy roof prism binoculars.
If you bought Pentax 8x24 and/or 8x25 binoculars, you bought roof prisms. Period.
Originally Posted By: moribundman
You may want to inform yourself properly.
Thanks for the laughs.
I look forward to your next syllable.
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In a porro prism design, objective lens and ocular lens (eyepiece) are offset, as clearly seen here:
This is a roof prism design:
You can deny it all you want!
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This is a roof prism design:
You can deny it all you want!
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Originally Posted By: moribundman
In a porro prism design ....
Pentax does not, and never has, made porro prism 8x24 or 8x25 binoculars.
http://www.pentax.ca/sportoptics/binos/index.php
Bon appetit, morbidman.
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In a porro prism design ....
Pentax does not, and never has, made porro prism 8x24 or 8x25 binoculars.
http://www.pentax.ca/sportoptics/binos/index.php
Bon appetit, morbidman.
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"Why do you need to carry binoculars with you so frequently? Who o you 'look' at? "
I like to carry low priced binoculars with acceptable / decent optics in the vehicles. I look at every one I find for $20 or less if I have the time, and have found decent ones for $10 to $20 at garage sales, rummage sales, and antique stores. You need to check for lose stuff, rattles, and then see how the optics are. At lunch today I noticed what looked like a large bird sitting in the grass at a campus, got the old 7x35 Tascos out of the truck and saw that it was a large owl.
The Tascos are a compact widefield porro design, a bit hefty for the size (means decent mechanics), need careful focusing because of the widefield oculars, but once focused provide decently sharp images. They're an old model I found in an antique store. I have a couple of other 7x35s, traditional porros,
My lifetime buy binouclars are some Fujinon 7x50 FMT-SX, ones that I picked after narrowing a long search to the Fujinons and some Nikon 7x50 Prostars. The Nikons were a tad better at the edges, the Fujinons had better color transmission per my eyes, both were nitrogen filled, waterproof, IF, fairly heavy, superb contrast, superb resolution, but the Nikons had a lot shorter eye relief, no tripod mount, and were twice as expensive. You can't appreciate the image quality until you tripod mount them. Now the Fujinons seem to be a lot more expensive, and looking thru new stuff I see no reason to upgrade.
It's supposed to be fun so you better be having fun.
:^)
I like to carry low priced binoculars with acceptable / decent optics in the vehicles. I look at every one I find for $20 or less if I have the time, and have found decent ones for $10 to $20 at garage sales, rummage sales, and antique stores. You need to check for lose stuff, rattles, and then see how the optics are. At lunch today I noticed what looked like a large bird sitting in the grass at a campus, got the old 7x35 Tascos out of the truck and saw that it was a large owl.
The Tascos are a compact widefield porro design, a bit hefty for the size (means decent mechanics), need careful focusing because of the widefield oculars, but once focused provide decently sharp images. They're an old model I found in an antique store. I have a couple of other 7x35s, traditional porros,
My lifetime buy binouclars are some Fujinon 7x50 FMT-SX, ones that I picked after narrowing a long search to the Fujinons and some Nikon 7x50 Prostars. The Nikons were a tad better at the edges, the Fujinons had better color transmission per my eyes, both were nitrogen filled, waterproof, IF, fairly heavy, superb contrast, superb resolution, but the Nikons had a lot shorter eye relief, no tripod mount, and were twice as expensive. You can't appreciate the image quality until you tripod mount them. Now the Fujinons seem to be a lot more expensive, and looking thru new stuff I see no reason to upgrade.
It's supposed to be fun so you better be having fun.
:^)
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Originally Posted By: Rolf
Originally Posted By: moribundman
In a porro prism design ....
Pentax does not, and never has, made porro prism 8x24 or 8x25 binoculars.
http://www.pentax.ca/sportoptics/binos/index.php
Bon appetit, morbidman.
If you can't identify a porro prism design by the pictures that I posted (which means you are utterly clueless!), I guess you need to see the spec sheet:
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Eat crow, Mickey Mose.
Originally Posted By: moribundman
In a porro prism design ....
Pentax does not, and never has, made porro prism 8x24 or 8x25 binoculars.
http://www.pentax.ca/sportoptics/binos/index.php
Bon appetit, morbidman.
If you can't identify a porro prism design by the pictures that I posted (which means you are utterly clueless!), I guess you need to see the spec sheet:
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Eat crow, Mickey Mose.
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Originally Posted By: moribundman
Eat crow, Mickey Mose.
So, let me get this straight.
You bought a pair of Chinese-made *inverted* porro prism binoculars, and you have the chutzpah to complain about them?
By 1900 perfect porro prism designs were ubiquitous.
One can buy 6x30, 8x30, and 8x24 binoculars based on the Zeiss designs for under $100 - even under $50 - day in and day out:
http://www.holgermerlitz.de/kronos6x30.html
http://www.holgermerlitz.de/zeiss8x30.html
http://www.holgermerlitz.de/nikon8x32.html
http://www.holgermerlitz.de/seven8x30.html
http://cgi.ebay.com/1943-USN-Binoculars-...%3A1%7C294%3A50
Get a grip on yourself.
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Eat crow, Mickey Mose.
So, let me get this straight.
You bought a pair of Chinese-made *inverted* porro prism binoculars, and you have the chutzpah to complain about them?
By 1900 perfect porro prism designs were ubiquitous.
One can buy 6x30, 8x30, and 8x24 binoculars based on the Zeiss designs for under $100 - even under $50 - day in and day out:
http://www.holgermerlitz.de/kronos6x30.html
http://www.holgermerlitz.de/zeiss8x30.html
http://www.holgermerlitz.de/nikon8x32.html
http://www.holgermerlitz.de/seven8x30.html
http://cgi.ebay.com/1943-USN-Binoculars-...%3A1%7C294%3A50
Get a grip on yourself.
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Nobody who knows the basic difference between a porro and a roof prism design can possibly not identify either design immediately. The difference is clear to see for anyone! Well, you obviously can or choose to ignore the obvious. Either you are blind as a bat and totally unknowledgeable, or you choose to lie because you just can't be wrong. If you'd rather lie than admit to being wrong, then shame on you, you little, little man!
From the spec sheet of the current Pentax 8x35 UCF:
Current Pentax porro prism binocs:
Papillo
UCF WP
UCF Zoom II
UCF X II
UCF R
MCF Jupiter II
Find them on pentaxsportoptics.com.
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From the spec sheet of the current Pentax 8x35 UCF:
Current Pentax porro prism binocs:
Papillo
UCF WP
UCF Zoom II
UCF X II
UCF R
MCF Jupiter II
Find them on pentaxsportoptics.com.
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