| |
Main
Date: 12 Oct 2006 15:58:16
From: brucegooglegroups
Subject: Wide angle and FOV
|
In binoculars, what is the definition of wide angle? For example, the
Orion Scenix 7x50s have a slightly larger FOV than the Scenix 10X50's
which are considered "wide angle".
Bruce
|
|
| |
Date: 13 Oct 2006 00:26:32
From: Sam Wormley
Subject: Re: Wide angle and FOV
|
brucegooglegroups wrote:
> In binoculars, what is the definition of wide angle? For example, the
> Orion Scenix 7x50s have a slightly larger FOV than the Scenix 10X50's
> which are considered "wide angle".
>
> Bruce
>
Look at the table down about half way on this web page... shows FOV
for various binoculars.
http://edu-observatory.org/eo/binoculars.html
|
| |
Date: 12 Oct 2006 23:30:08
From: Alan French
Subject: Re: Wide angle and FOV
|
"brucegooglegroups" <brucegooglegroups@hotmail.com > wrote in message
news:1160693896.712257.316860@b28g2000cwb.googlegroups.com...
> In binoculars, what is the definition of wide angle? For example, the
> Orion Scenix 7x50s have a slightly larger FOV than the Scenix 10X50's
> which are considered "wide angle".
Bruce,
In the world of advertising, it's hard to say <g >.
Generally, lower magnifications yield a wider true field. In terms of FOV,
the Scenix 10x50s do have a somewhat wider field than many 10x50s, and I
think that is why they advertise them as "wide angle." Binocular eyepieces
generally provide an apparent field of from 50 to 67 or so degrees, and the
Scenix must have an eyepiece with an apparent field near the higher end. I
think it would be reasonable to think of any binocular with an eyepiece with
an apparent field aroudn 67 degrees as "wide angle."
Clear skies, Alan
|
| | |
Date: 13 Oct 2006 01:28:16
From: Mike L'Mao
Subject: Re: Wide angle and FOV
|
>
> Generally, lower magnifications yield a wider true field. In terms of
> FOV,
> the Scenix 10x50s do have a somewhat wider field than many 10x50s, and I
> think that is why they advertise them as "wide angle." Binocular
> eyepieces
> generally provide an apparent field of from 50 to 67 or so degrees, and
> the
> Scenix must have an eyepiece with an apparent field near the higher end.
> I
> think it would be reasonable to think of any binocular with an eyepiece
> with
> an apparent field aroudn 67 degrees as "wide angle."
>
> Clear skies, Alan
Ummm..why are you mentioning AFOV when it really means nothing??
The scenix the OP'r talks of are 6 and 7 degrees FOV. Which are astounding.
My bushnell 10X50's have a meager 5.5 deg.
|
| | | |
Date: 12 Oct 2006 21:52:12
From: Willie R. Meghar
Subject: Re: Wide angle and FOV
|
Bruce asked:
>>>In binoculars, what is the definition of wide angle?
Alan French wrote:
>> I think it would be reasonable to think of any binocular with an eyepiece
>> with an apparent field aroudn 67 degrees as "wide angle."
Mike L'Mao responded:
>Ummm..why are you mentioning AFOV when it really means nothing??
I think most knowledgeable individuals would be satisfied with Alan's
suggestion. It makes far more sense to respond to the original
question in terms of apparent field than in terms of true field.
AFOV = TFOV multiplied by Magnification
where AFOV is 'Apparent Field Of View' and TFOV is 'True FOV'.
By using AFOV, the definition remains the same for *any* (such as:
7x35, 8x42, 9x63, 10x50, 11x80, 20x80, 25x100, 25x150, etc.)
binocular.
Willie R. Meghar
Observational Notes at:
http://meghar.blogspot.com/
|
| | | | |
Date: 13 Oct 2006 05:01:39
From: Mike L'Mao
Subject: Re: Wide angle and FOV
|
"Willie R. Meghar" <NoMail@thisaddress.net > wrote in message
news:oa3ui21olonpg27f6lcb4m3hhcrilot21h@4ax.com...
> Bruce asked:
>
>>>>In binoculars, what is the definition of wide angle?
>
> Alan French wrote:
>
>>> I think it would be reasonable to think of any binocular with an
>>> eyepiece
>>> with an apparent field aroudn 67 degrees as "wide angle."
>
> Mike L'Mao responded:
>
>>Ummm..why are you mentioning AFOV when it really means nothing??
>
> I think most knowledgeable individuals would be satisfied with Alan's
> suggestion. It makes far more sense to respond to the original
> question in terms of apparent field than in terms of true field.
>
> AFOV = TFOV multiplied by Magnification
>
> where AFOV is 'Apparent Field Of View' and TFOV is 'True FOV'.
>
> By using AFOV, the definition remains the same for *any* (such as:
> 7x35, 8x42, 9x63, 10x50, 11x80, 20x80, 25x100, 25x150, etc.)
> binocular.
you guys are all crazy.
|
| | | |
Date: 13 Oct 2006 02:53:22
From: Alan French
Subject: Re: Wide angle and FOV
|
"Mike L'Mao" <LMAO@telusplanet.com > wrote in message
news:QYBXg.11652$P7.1961@edtnps90...
> >
> > Generally, lower magnifications yield a wider true field. In terms of
> > FOV,
> > the Scenix 10x50s do have a somewhat wider field than many 10x50s, and I
> > think that is why they advertise them as "wide angle." Binocular
> > eyepieces
> > generally provide an apparent field of from 50 to 67 or so degrees, and
> > the
> > Scenix must have an eyepiece with an apparent field near the higher end.
> > I
> > think it would be reasonable to think of any binocular with an eyepiece
> > with
> > an apparent field aroudn 67 degrees as "wide angle."
> >
> > Clear skies, Alan
>
>
> Ummm..why are you mentioning AFOV when it really means nothing??
>
> The scenix the OP'r talks of are 6 and 7 degrees FOV. Which are
astounding.
> My bushnell 10X50's have a meager 5.5 deg.
A larger AFOV translates into a wider true field. The true field is
approximately the apparent FOV divided by the magnification. At a given
magnification, a larger AFOV means a larger true field. You aren't going to
have a "wide angle" binocular with an AFOV of 50 degrees.
Clear skies, Alan
|
| | | | |
Date: 13 Oct 2006 03:00:05
From: Mike L'Mao
Subject: Re: Wide angle and FOV
|
>> My bushnell 10X50's have a meager 5.5 deg.
>
> A larger AFOV translates into a wider true field. The true field is
> approximately the apparent FOV divided by the magnification. At a given
> magnification, a larger AFOV means a larger true field. You aren't going
> to
> have a "wide angle" binocular with an AFOV of 50 degrees.
Fine but I don't think most people know that. You didn't give the relation
between
AFOV and FOV in your answer to the OP'r.
|
| | | | | |
Date: 12 Oct 2006 20:58:04
From: Bob May
Subject: Re: Wide angle and FOV
|
Pick nits fine enough and you'll be reading 20K of writing just to get
across a simple point.
In other words, don't assume that the OP doesn't know at least some of the
terminology used and if he doesn't happen to know, let him find out rather
than demand it from those who answer. IN other words, if YOU don't know,
first go find out what it means and only ask if you can't find it out.
--
Yeppie, Bush is such an idiot that He usually outwits
everybody else. How dumb!
|
| | | | | |
Date: 13 Oct 2006 12:48:29
From: Alan French
Subject: Re: Wide angle and FOV
|
"Mike L'Mao" <LMAO@telusplanet.com > wrote in message
news:ViDXg.14515$P7.6256@edtnps89...
>
> >> My bushnell 10X50's have a meager 5.5 deg.
> >
> > A larger AFOV translates into a wider true field. The true field is
> > approximately the apparent FOV divided by the magnification. At a given
> > magnification, a larger AFOV means a larger true field. You aren't
going
> > to
> > have a "wide angle" binocular with an AFOV of 50 degrees.
>
> Fine but I don't think most people know that. You didn't give the relation
> between
> AFOV and FOV in your answer to the OP'r.
It is always hard to tell how much information to include in a reply. I
tend to avoid lengthy replies, and figure people will ask for clarification
if it is needed. I usually assume people know some basic information, but
that is not always the case.
I also try to avoid being snippish.
Clear skies, Alan
|
| | | | | | |
Date: 13 Oct 2006 12:53:58
From: Mike L'Mao
Subject: Re: Wide angle and FOV
|
"Alan French" <adfrenchremoveallthis@nycap.rr.com > wrote in message
news:xWLXg.6541$0L1.1651@twister.nyroc.rr.com...
> "Mike L'Mao" <LMAO@telusplanet.com> wrote in message
> news:ViDXg.14515$P7.6256@edtnps89...
>>
>> >> My bushnell 10X50's have a meager 5.5 deg.
>> >
>> > A larger AFOV translates into a wider true field. The true field is
>> > approximately the apparent FOV divided by the magnification. At a
>> > given
>> > magnification, a larger AFOV means a larger true field. You aren't
> going
>> > to
>> > have a "wide angle" binocular with an AFOV of 50 degrees.
>>
>> Fine but I don't think most people know that. You didn't give the
>> relation
>> between
>> AFOV and FOV in your answer to the OP'r.
>
> It is always hard to tell how much information to include in a reply. I
> tend to avoid lengthy replies, and figure people will ask for
> clarification
> if it is needed. I usually assume people know some basic information, but
> that is not always the case.
>
> I also try to avoid being snippish.
>
> Clear skies, Alan
Also, I never said my bushnells were "wide field" but 5.5 degrees in a
telescope WOULD be ...so go figure.
|
| | | |
Date: 13 Oct 2006 15:31:31
From: Llanzlan Klazmon the 15th
Subject: Re: Wide angle and FOV
|
"Mike L'Mao" <LMAO@telusplanet.com > wrote in
news:QYBXg.11652$P7.1961@edtnps90:
>
>
>>
>> Generally, lower magnifications yield a wider true field. In terms of
>> FOV,
>> the Scenix 10x50s do have a somewhat wider field than many 10x50s, and
>> I think that is why they advertise them as "wide angle." Binocular
>> eyepieces
>> generally provide an apparent field of from 50 to 67 or so degrees, and
>> the
>> Scenix must have an eyepiece with an apparent field near the higher
>> end. I
>> think it would be reasonable to think of any binocular with an eyepiece
>> with
>> an apparent field aroudn 67 degrees as "wide angle."
>>
>> Clear skies, Alan
>
>
> Ummm..why are you mentioning AFOV when it really means nothing??
>
> The scenix the OP'r talks of are 6 and 7 degrees FOV. Which are
> astounding. My bushnell 10X50's have a meager 5.5 deg.
>
>
A greater AFOV allows you to get the same TFOV with a smaller exit pupil.
That's why.
Klazmon.
|
| | | |
Date: 13 Oct 2006 01:31:58
From: Mike L'Mao
Subject: Re: Wide angle and FOV
|
>
> The scenix the OP'r talks of are 6 and 7 degrees FOV. Which are
> astounding.
Ooops...7 degs for each rather.
|
|
