In this context, "original files" are exportet from Adobe Photoshop Lightroom and may be .tif or .jpg
Here is my current portion of code to transfert properties
Image inputImage = Image.FromFile(currentFile.FullName);
...
[SomeTreatements including resize+watermarking]
...
foreach (System.Drawing.Imaging.PropertyItem p in inputImage.PropertyItems)
outputImage .SetPropertyItem(p);
outputImage.Save(...);
After this, inputImage and outputImage have the same number of PropertyItem. They have 21.
But the file metadata only keeps "Authors", "Program name", "Copyright", "Camera maker", "Camera model".
Other fields I'm interested in that get lost are: "DateTaken", "F-stop", "Exposure time", "ISO speed", "Focal length", "Max aperture", "Metering mode", "No flash","White balance", "Photometric interpretation".
(Other fields I may be interested to keep but are not always filled in my original files, so I cannot tell if they are lost for now: "35mm focal length", "Subject distance", "Flash energy")
Original file mentions: "EXIF version: 0230", output file has no EXIF version.
Thank you for your help.