[KPhotoAlbum] "F Number" vs. "Aperture Value"

Johannes Zarl-Zierl johannes at zarl-zierl.at
Mon Dec 2 22:32:30 GMT 2019


Forgive me my technical illiteracy - I didn't realize that there are two 
almost identical measures at play here.

The value called "Aperture Value" in the UI corresponds to 
Exif.Photo.ApertureValue, which is the APEX[1] value.
The value called "F Number" is Exif.Photo.FNumber, which is the focal ratio as 
commonly used.

For better clarity, I propose we relabel the first entry to "Aperture Value 
(APEX)" and the second one to "Aperture Value (F Number)".
>From what I've read about APEX though, I conclude that the APEX aperture value 
should have different values, i.e. the range is probably incorrect.


[1] https://de.wikipedia.org/wiki/Additive_System_of_Photographic_Exposure

Am Sonntag, 1. Dezember 2019, 02:49:26 CET schrieb Johannes Zarl-Zierl:
> Hi Robert,
> Am Samstag, 30. November 2019, 03:41:28 CET schrieb Robert Krawitz:
> > Why are there two separate controls in the search dialog?  They mean
> > the same thing (but don't have the same effect -- one finds zero
> > matches while the other finds the correct matches).
> That's an interesting question. A casual glance at the source code doesn't
> help, unfortunately: apparently both the aperture and the f-number were
> added within a short amount of time (33cfb31cf vs 803e77395).
> My best guess is that fnumber was first renamed to aperture, and then a
> mistake was made when applying some patch, reintroducing fnumber...
>   Johannes
> _______________________________________________
> KPhotoAlbum mailing list
> KPhotoAlbum at mail.kdab.com
> https://mail.kdab.com/mailman/listinfo/kphotoalbum

More information about the Kphotoalbum mailing list