Angle of view instead of focal length

Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.
--

Alfred Molon
------------------------------
Olympus E-series DSLRs and micro 4/3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

On Tue, 02 Oct 2012 23:36:10 +0200, Alfred Molon wrote:

Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.

Your point is well taken, but usually there is the actual focal length
and a '35mm equivalent'. Personally, I think I'd rather see focal length
divided by diagonal of the sensor. Then I'd know that 1.0 means it's a
'normal' view, less than 1.0 is 'wide angle' and greater than 1.0
'telephoto' and it would also give the magnification.

Alfred Molon writes:

Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.

Except for the fact that few of us are used to thinking in those terms,
yes, I think it would.

--
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On 10/2/2012 2:36 PM, Alfred Molon wrote:
Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.


Focal length would be a constant regardless of sensor size while the
angle of view would a variable. However, the suggestion that the EXIF
also include the angle of view, if one feels the need of it, might be an
asset.

On 3/10/2012 7:36 AM, Alfred Molon wrote:
Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.



I have never though in angle of view with my DX format Nikons always in
focal length.

I'm aware of the angles of my 16mm and 20mm lenses that's all, but if
you ask, I could not tell you, what the angles were for the rest of my
lenses.

It would be a stupid idea to know what the angle of view was for a 300mm
or 500 mm lens. How would you replicate back to what lens you used.

Things are in mm not angles.

Alfred Molon wrote:
Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.

I take you are unaware that there is indeed an EXIF
field for the field of view in degrees. At least Nikon
and Canon both provide that data.

Examples:

Camera Model Name : NIKON D3S
Field Of View : 72.7 deg (1.96 m)
Focal Length : 24.0 mm (35 mm equivalent: 24.0 mm)

Camera Model Name : NIKON D4
Field Of View : 68.5 deg (2.04 m)
Focal Length : 24.0 mm (35 mm equivalent: 26.0 mm)

Camera Model Name : NIKON D800
Focal Length : 800.0 mm (35 mm equivalent: 800.0 mm)
Field Of View : 2.5 deg (2.09 m)

Camera Model Name : Canon EOS 60D
Focal Length : 50.0 mm (35 mm equivalent: 78.6 mm)
Field Of View : 25.8 deg

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

In article , Floyd L. Davidson says...
I take you are unaware that there is indeed an EXIF
field for the field of view in degrees. At least Nikon
and Canon both provide that data.

Examples:

Camera Model Name : NIKON D3S
Field Of View : 72.7 deg (1.96 m)
Focal Length : 24.0 mm (35 mm equivalent: 24.0 mm)

Camera Model Name : NIKON D4
Field Of View : 68.5 deg (2.04 m)
Focal Length : 24.0 mm (35 mm equivalent: 26.0 mm)

Camera Model Name : NIKON D800
Focal Length : 800.0 mm (35 mm equivalent: 800.0 mm)
Field Of View : 2.5 deg (2.09 m)

Camera Model Name : Canon EOS 60D
Focal Length : 50.0 mm (35 mm equivalent: 78.6 mm)
Field Of View : 25.8 deg

Interesting. Which cameras support this field?

And is there a difference between field of view and angle of view?
--

Alfred Molon
------------------------------
Olympus E-series DSLRs and micro 4/3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

Alfred Molon wrote:
Given the wide variety of sensor sizes, wouldn't it be better if the
EXIF of a photo contained also the angle of view information? The focal
length of the lens is not really that important, actually it is quite
irrelevant.

Of focal length, sensor size and field of view you need (any) two.
The third can be calculated. Since your viewing of EXIF
is always mediated by software, this is a non-issue.

BugBear

In article , bugbear
says...
Of focal length, sensor size and field of view you need (any) two.
The third can be calculated. Since your viewing of EXIF
is always mediated by software, this is a non-issue.

Of course everything can be calculated, but actually focal length and
sensor size are irrelevant. What really matters is the angle of view.
--

Alfred Molon
------------------------------
Olympus E-series DSLRs and micro 4/3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site

Alfred Molon wrote:
In article , Floyd L. Davidson says...
I take you are unaware that there is indeed an EXIF
field for the field of view in degrees. At least Nikon
and Canon both provide that data.

Examples:

Camera Model Name : NIKON D3S
Field Of View : 72.7 deg (1.96 m)
Focal Length : 24.0 mm (35 mm equivalent: 24.0 mm)

Camera Model Name : NIKON D4
Field Of View : 68.5 deg (2.04 m)
Focal Length : 24.0 mm (35 mm equivalent: 26.0 mm)

Camera Model Name : NIKON D800
Focal Length : 800.0 mm (35 mm equivalent: 800.0 mm)
Field Of View : 2.5 deg (2.09 m)

Camera Model Name : Canon EOS 60D
Focal Length : 50.0 mm (35 mm equivalent: 78.6 mm)
Field Of View : 25.8 deg

Interesting. Which cameras support this field?

And is there a difference between field of view and angle of view?

There are different values used for field or angle of view. Sometimes
it's calculated across the sensor diagnonal, i.e. the diameter of the
image circle, sometimes across the width of the sensor. The number I
find much more photographically useful is the angle derived from the
width across the sensor in normal (landscape) mode. That tells me how
wide the standard view is without seriously tilting the camera to
squeeze more width out corner to opposite corner across the diagonal.

--
Chris Malcolm