How can I tell what lens 'spec' is 'wide angle'?

steve

Distinguished

How do interpret the figures given for lenses i.e. 28mm-114mm in conjunction
with zoom, f factor etc to gauge whether a camera has a good wide or poor
narrow field of view? I would rather know what width of view the camera
would take at what distance as these figures are meaningless to me - unless
someone can explain?!

G

Guest

Guest

Steve wrote:
> How do interpret the figures given for lenses i.e. 28mm-114mm in
> conjunction with zoom, f factor etc to gauge whether a camera has a
> good wide or poor narrow field of view? I would rather know what
> width of view the camera would take at what distance as these figures
> are meaningless to me - unless someone can explain?!

You are right. Without all the information it is meaningless.

Even the same lens on different cameras can give different results.

The usual 7X or 3X or ?X just means that the most telephoto view will
look 7 or 3 or ? times closer than the wide setting. It does not tell you
if the lens is wide angle, telephoto or spans both.

the question (like you are ready to buy a new camera and want to know if the
Acme 5000 model will work well with sports shots of your kids baseball games
and also the family around the Christmas dinner table.

--
Joseph Meehan

Dia duit

Jim

Distinguished

"Steve" <xsx2000x@Zyahoo.com> wrote in message
news:tIIoe.8254\$%21.1580@newsfe2-gui.ntli.net...
> How do interpret the figures given for lenses i.e. 28mm-114mm in
conjunction
> with zoom, f factor etc to gauge whether a camera has a good wide or poor
> narrow field of view? I would rather know what width of view the camera
> would take at what distance as these figures are meaningless to me -
unless
> someone can explain?!
I assume these terms are the "35mm equivalent focal lengths". All focal
lengths shorter than 50mm are considered wide angle even though the normal
lens for the 35mm format should be about 44mm.
The shorter the focal length, the more pronounced the wide angle effect is.
Thus 28mm focal length is a useful wide angle lens.
The 114 mm setting is a very moderate telephoto setting. You will find that
this focal length can make excellent portraits.
Jim
>
>

dylan

Distinguished

"Steve" <xsx2000x@Zyahoo.com> wrote in message
news:tIIoe.8254\$%21.1580@newsfe2-gui.ntli.net...
> How do interpret the figures given for lenses i.e. 28mm-114mm in
> conjunction
> with zoom, f factor etc to gauge whether a camera has a good wide or poor
> narrow field of view? I would rather know what width of view the camera
> would take at what distance as these figures are meaningless to me -
> unless
> someone can explain?!
>
>

You will get the angle of view from the focal length (in your example the
28-114mm) but this has to be related to the size of the sensor eg 35mm.
In most cases they will normally quote relative to 35mm cameras as these are
common.
Take a look at
http/www.canon.co.uk/For_Home/Product_Finder/Cameras/EF_Lenses/Zoom_Lenses/EF_28135mm_f3556IS_USM/
for an example where they will quote the angle of view for the 28-135mm lens
for a 35mm camera. The largest angle being the 28mm setting.
In 35mmm terms Wide angle is usually around 28mm or less, <20mm will be very
wide. >100mm is telephoto

the f number has no effect on angle of view and the zoom just gives the
range ie 28-135 had a zoom range of 135/28 = 4.8x

G

Guest

Guest

"Steve" <xsx2000x@Zyahoo.com> writes:
> How do interpret the figures given for lenses i.e. 28mm-114mm in
> conjunction with zoom, f factor etc to gauge whether a camera has a
> good wide or poor narrow field of view?

You can't tell whether it is wide angle from the focal length
alone - yiou also need to know what size the imager is.

f=28mm is wide angle on a camera using 135-film (aka. "full frame),
it is darned closed to "normal" on a consumer digicam such as the
Canon EOS 20D, and 28mm gives the FOV of a telephoto lens on a compact
such as the Canon Powershot G5.

> I would rather know what width of view the camera would take at what
> distance as these figures are meaningless to me - unless someone can
> explain?!

This web page show you how to compute FOV if you know the focal
length and imager size:
http/folk.uio.no/gisle/photo/crop.html
--
- gisle hannemyr [ gisle{at}hannemyr.no - http/folk.uio.no/gisle/ ]
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Kodak DCS460, Canon Powershot G5, Olympus 2020Z
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