Add property "Field of View" (FoV)

[nji9]

The detailed photo properties are very useful

The "focal length" however makes only sense in connection with the sensor size.
(E.g. focal length 7mm will be a very wide angle photo for large sensors,
and it will be about a telephoto on small (e.g. smartphone) sensors).

The property that reflects the angle type/ photo expression is "Field of View".

It can be calculated very easy by

FoV = 2 * arctan (SensorSize / (2 * focal length)).

But where to get the sensor size from?

Easy:
In the properties there are already Maker and Model.
From this you can get the sensor size directly by several sources.
Preferably https://github.com/openMVG/CameraSensorSizeDatabase

Having the FoV at hand isn't only useful for searching,
but also for assessing what "is the reality" of a photo.

BTW.
FishEye lenses need special treatment (which shouldn't be a problem).

Addendum:
CameraSensorSizeDatabase seems to be outdated.
What I found:
https://letmaik.github.io/pixelpitch/
https://www.dxomark.com/Cameras/
https://www.digicamdb.com/
https://www.lensation.de/sensor-db/
https://cameradecision.com/
https://www.dpreview.com/products/search/cameras
https://www.camerafv5.com/devices/

[jkm]

The detailed photo properties are very useful

If you’re referring to the newly available “exiftool values”, I'm glad you like them.

However, XnViewMP is not calculating or manufacturing any of this data. It only reports data that Exiftool returns. This is by design.

If you want new metadata like what you describe to be added, you should go over to the exiftool forum (google if you don’t know it) and request that Phil Harvey add the functionality you seek.

If he does, it will automatically be incorporated into XnViewMP.

[nji9]

I'm referring the items showing below "Properties" at the "Catalog Filter" pane,
like "Orientation", "Aspect Ratio", "Maker" etc.

But you got me wrong.

I know XnViewMP isn't calculating these data, but gets them "externally".

To show the "Field of View" (FoV) - it's this useful value what I'm about -
you either need: Crop factor or focal lenght (for 35mm film) or sensor size.

Crop factor and focal length (for 35mm film) sometimes are in EXIF data,
sensor size isn't and never will be.

So the only reliable (and easy) way to show FoV to the user is to calculate it
from sensor size.

As Maker and Model are already part of the (EXIF) "Properties",
all that is needed is the sensor size for each of them.

Best like in https://github.com/openMVG/CameraSensorSizeDatabase
But as it is last updated in 2019, it needs a refresh.
This can be easily done with public available data
(maybe easiest from https://www.dxomark.com/Cameras/).

(Fisheye lenses need a special treatment/ formula;
but as they are only few, and their FoV is usually about constant,
it could be obtained directly to a csv.
Actually I will provide the list to the master soon ).

[jkm]

But you got me wrong.

No, I understood you right.

I also understand that you're using the term Field of View incorrectly, because you were probably getting your formula from AI or the Wikipedia article, which is unfortunately wrong. In optical lens systems, like a camera, “field of view” is properly a linear measurement dependent on the distance to the subject. Your formula calculates Angle of View, which is an angular measurement. (And that formula returns the angle in radians, when most people would prefer degrees.). Wikipedia says field of view and angle of view are the same. But they are not. It's unfortunately a common mistake, so there's a lot of misinformation out there.

Google “angle of view vs field of view” to learn more.

I know sensor size is not usually in EXIF, but you might be surprised. Olympus/OMDS has a tag FocalPlaneDiagonal which is a direct measurement of sensor size in mm. Canon includes FocalPlaneXResolution which is in DPI and can be used to calculate the sensor size.

But most importantly, Exiftool already provides a composite tag called ScaleFactorTo35mmEquivalent which gives you a direct relationship between the size of the camera sensor and a full frame sensor. 1 means FF, 1.6 is APSC, and 2 is MFT, and so on.

So Exiftool already has the data needed for it to calculate Angle of View.

Again, I suggest you ask on the Exiftool forum for the AoV calculation to be added there, because you have a better chance of getting it done. Doing lookups or calculations on EXIF data is not what XnView is doing.

Or, you might just consider adding the calculation to Exiftool yourself. The .Exiftool_config file allows you to create user-defined tags, and it allows you to execute arbitrary Perl code to do it. So simply write a small function to perform the calculation and put it in a composite tag called AoV (or FoV if you prefer) and add that to your .Exiftool_config file, and it will be available in XnViewMP. You can ask how to do this on the Exiftool forum if you can’t figure it out from the documentation. It’s not difficult at all.

Good luck. I hope this information was helpful.

[nji9]

Sorry (really!) , but you are totally wrong (see below).

I also understand that you're using the term Field of View incorrectly, because you were probably getting your formula from AI or the Wikipedia article, which is unfortunately wrong. In optical lens systems, like a camera, “field of view” is properly a linear measurement dependent on the distance to the subject. Your formula calculates Angle of View, which is an angular measurement. (And that formula returns the angle in radians, when most people would prefer degrees.). Wikipedia says field of view and angle of view are the same. But they are not. It's unfortunately a common mistake, so there's a lot of misinformation out there.

Google “angle of view vs field of view” to learn more.

These are lot of insinuations, wrong statements, and misunderstanding.

FoV is in angles right (Do you really need the formula from radians to degrees? )
The way it is used commonly has nothing to do with object distance.
(Exception: In binoculars field of view mostly is given by the viewable width for a special distance.
A consequence by the lens' property: its angle that determines the "kind of vision" - see my first post).

I know sensor size is not usually in EXIF, but you might be surprised. Olympus/OMDS has a tag FocalPlaneDiagonal which is a direct measurement of sensor size in mm. Canon includes FocalPlaneXResolution which is in DPI and can be used to calculate the sensor size.

But most manufactures do not, and did not, and won't ever.

But most importantly, Exiftool already provides a composite tag called ScaleFactorTo35mmEquivalent which gives you a direct relationship between the size of the camera sensor and a full frame sensor. 1 means FF, 1.6 is APSC, and 2 is MFT, and so on.

... and this tag in 99.99% isn't used.

So Exiftool already has the data needed for it to calculate Angle of View.

... and this tag in 99.99% isn't used.

Again, I suggest you ask on the Exiftool forum for the AoV calculation ...

You can't calculate something, if necessary tags are not, and haven't been filled.
If they had been there in the past at all.

Sorry, Mr. "AoV" (never heard of that ), but your post is wrong all over.

P.S.
You are right, that in principle the correct term would be angle of view.
But the common term for the angle is "field of view" (FoV, hFoV, vFoV, dFoV).

[jkm]

Sorry (really!) , but you are totally wrong (see below).

Unfortunately, you don't know what you're talking about. It's regrettable to need to be so blunt, but I don't want other readers to be mislead by all the errors in your post.

These are lot of insinuations, wrong statements, and misunderstanding.

Yes, on your part.

FoV is in angles right (Do you really need the formula from radians to degrees? )

You evidently don't know the difference or the consequences. Do you expect the value for a wide angle lens to be 1.9, or 110? Why else did you provide a formula that gives an answer that isn't exactly what want or what users would expect?

... and this tag in 99.99% isn't used.

Not used by whom? You? I'm not surprised. But Exiftool shows it for all my camera images. If you have a lot of camera images where Exiftool is not presenting the ScaleFactorTo35mmEquivalent value, then go complain on the Exiftool forum. Then go learn how to use it.

Start by reading this: https://exiftool.org/config.html

I had considered writing the function for you, to be nice so that you could just use it. But after reading your post, I changed my mind.

The ability to add arbitrary user-defined tags (which can do very complex calculations if necessary in Perl) is a highly valuable capability and very useful information, for anyone that actually wants to learn. That's why I mentioned this. But perhaps other people can still benefit from it, even if you don't want to.

Sorry, Mr. "AoV" (never heard of that ), but your post is wrong all over.

Your ignorance, and the arrogance with which you assert it, is becoming rather appalling. Because you have never heard of something, you think it's wrong. You can't be bothered to look it up and correct yourself. You should have done a little more research, and been a little more open minded. The fact that you've never heard of Angle of View shows just how limited your knowledge and experience actually is.

It might interest you to know (although probably not, because you can't accept you're wrong) that both Canon and Nikon specify their lenses using Angle of View, not field of view. Here are some links. Read the specs.
https://www.nikonusa.com/p/nikkor-z-20m ... tech-specs
https://en.canon-cna.com/lenses/rf-16mm ... fications/

Nikon says: "Maximum Angle of View (DX-format) 70°"
Canon says: "Angle of View (Horizontal, vertical, diagonal) 98°, 74°10, 108°10"

And the angle is specified in degrees, not radians. (Why? Because that is how people expect it. Which means that the formula you got from a chatbot is useless for the intended purpose. If you were shown in the GUI that metadata for all your images, and the range of values was 0 to 3.14, as your formula would provide, you would complain.)

So does Sony: https://electronics.sony.com/imaging/le ... /sel16f18g
So does Fuji: https://shopusa.fujifilm-x.com/xf14mmf2 ... attributes
So does Olympus/OM System: https://explore.omsystem.com/us/en/m-zu ... -pro-black

Read the specs.

The engineers who are providing the specifications to the marketing people actually know what they're talking about. Since you're disputing it, what does that say about you?

P.S.
You are right, that in principle the correct term would be angle of view.

CONGRATULATIONS! Finally, at the end, you show a glimmer of understanding.

But the common term for the angle is "field of view" (FoV, hFoV, vFoV, dFoV).

Many mistakes are common. Lots of people say dolphins are fish. Lots of people use the "word" irregardless. Lots of people think weight and mass are the same. Or that Centrifugal Force exists. They are wrong. Being common does not make it correct, nor does the fact that Wikipedia perpetuates it.

So many people make the mistake about FoV that it has become a highly ambiguous term. When discussing technical matters, an ambiguous term is useless. It's like talking about the "size" of an image. What does that actually mean? This is why you start to see people talk about "Angular Field of View AFoV" or "Linear Field of View LFoV" because the misused term "FoV" by itself has become useless. If people could correctly refer to the "dimensions" of an image instead of "size" then much confusion would be eliminated. Likewise AoV and FoV should be used correctly.

If you're going to suggest that software be modified to include new data, at least make the suggested data correct.

Bottom line: You can add what you want to Exiftool today through a user-defined tag, or ask for someone else to update their software for you and wait.

Please just educate yourself before you embarrass yourself further. Try to learn before trying to argue.

Goodbye.

[nji9]

Sigh... no comment on that...

But...I just noticed that there is another EXIF tag
that - if set - can be used to calculate sensor size:

FocalPlaneX/YResolution and -Unit.

For most images I have access to, sensor size could be calculated in that way.

Only for my very first digital camera (Kodak DC280 Zoom Digital)
the EXIF data don't suffice to calculate sensor size.

[user0]

Many mistakes are common. Lots of people say dolphins are fish. Lots of people use the "word" irregardless. Lots of people think weight and mass are the same. Or that Centrifugal Force exists. They are wrong. Being common does not make it correct, nor does the fact that Wikipedia perpetuates it.

wow, wow, wow, easy there, Mr.Right
at this rate we'll soon discover that the Earth is round and that americans really did land on the Moon