Ok, through a lot of different posts I managed to piece together something that works.
However I would like to show more of the EXIF data and tried to modify following section in displayimage.php
if (isset($exif) && is_array($exif)) {
if (isset($exif['Camera'])) $info[$lang_picinfo['Camera']] = $exif['Camera'];
if (isset($exif['DateTaken'])) $info[$lang_picinfo['Date taken']] = $exif['DateTaken'];
if (isset($exif['Aperture'])) $info[$lang_picinfo['Aperture']] = $exif['Aperture'];
if (isset($exif['ExposureTime'])) $info[$lang_picinfo['Exposure time']] = $exif['ExposureTime'];
if (isset($exif['FocalLength'])) $info[$lang_picinfo['Focal length']] = $exif['FocalLength'];
if (isset($exif['Comment'])) $info[$lang_picinfo['Comment']] = $exif['Comment'];
}
to this
if (isset($exif) && is_array($exif)) {
if (isset($exif['Camera'])) $info[$lang_picinfo['Camera']] = $exif['Camera'];
if (isset($exif['DateTaken'])) $info[$lang_picinfo['Date taken']] = $exif['DateTaken'];
if (isset($exif['Aperture'])) $info[$lang_picinfo['Aperture']] = $exif['Aperture'];
if (isset($exif['ExposureTime'])) $info[$lang_picinfo['Exposure time']] = $exif['ExposureTime'];
if (isset($exif['FocalLength'])) $info[$lang_picinfo['Focal length']] = $exif['FocalLength'];
if (isset($exif['LongFocalLength'])) $info[$lang_picinfo['LongFocalLength']] = $exif['LongFocalLength'];
if (isset($exif['Comment'])) $info[$lang_picinfo['Comment']] = $exif['Comment'];
}
LongFocalLength is a property of canon digital cameras. But nothing is displayed from that field. I have verified with a different program that the field do contain a value. The same happens for other fields both common and canon specific fields.
ps I have added LongFocalLength to the language file.