AndroidX ExifInterface can read camera make/model but not lens make/model

I'm building an app which reads EXIF data from images and overlays that data on the image so you can share your camera settings with a nice graphic rather than manually typing them out (EG: "F/1.4 at 1/200 ISO400")

I'm using AndroidX ExifInterface 1.1.0-beta01 and the blow code works to get every piece of data except the LensMake and LensModel are always null.

I've tried reverting to ExifInterface 1.0.0 and that made no difference, it still behaves identically.

I note that the documentation for ExifInterface refers to LensMake and LensModel as returning an "ASCII String" which Camera Make and Camera Model just return a "String" so i've tried different variations of getAttribute without success.

These exact files work fine on the iOS version of the app I've previously built and i've tried files from multiple different cameras (Fuji X-T3, Canon 5D III)

var stream: InputStream? = null
try {
    stream = contentResolver.openInputStream(uri)
    val exifInterface = ExifInterface(stream!!)
    FS = exifInterface.getAttribute(ExifInterface.TAG_F_NUMBER)!!
    SS = exifInterface.getAttribute(ExifInterface.TAG_EXPOSURE_TIME)!!
    ISO = exifInterface.getAttribute(ExifInterface.TAG_PHOTOGRAPHIC_SENSITIVITY)!!

    val LensMake = exifInterface.getAttribute(ExifInterface.TAG_LENS_MAKE) //THIS APPEARS TO BE ALWAYS NULL :(
    val LensModel = exifInterface.getAttribute(ExifInterface.TAG_LENS_MODEL) //THIS APPEARS TO BE ALWAYS NULL :(
    val CameraMake = exifInterface.getAttribute(ExifInterface.TAG_MAKE)
    val CameraModel = exifInterface.getAttribute(ExifInterface.TAG_MODEL)
}

I'd like to be able to read the lens information, I know it's in the file but this library doesn't seem to want to expose it.

Solution

There is an open bug filed on the issue tracker, which states, that:

Although the constants are available for LensMake and LensModel, the getter does not return the actual values from the file. It seems like proper support is missing. I think the reason is that ExifTag[] IFD_EXIF_TAGS does not contain an array item for lens make and model. Adding the following lines at the right place of the aforementioned array, seems to fix things:

new ExifTag(TAG_LENS_MAKE, 42035, IFD_FORMAT_STRING),
new ExifTag(TAG_LENS_MODEL, 42036, IFD_FORMAT_STRING),

Not sure how reliable this is, but it is at least a solution approach.