gistfile1.cs

public class ExifInfo
{
    public static IList<Exif> ExifTagsToCapture;

    static ExifInfo()
    {
        ExifTagsToCapture = new List<Exif>
        {
            new Exif
            {
                ExifTag = CustomExifTags.Make,
                Show = true,
                Name = "Make",
                Id = (ushort)CustomExifTags.Make,
                ToString = value => value.ToString()
            },
            new Exif
            {
                ExifTag = CustomExifTags.Model,
                Show = true,
                Name = "Model",
                Id = (ushort)CustomExifTags.Model,
                ToString = value => value.ToString()
            },
            new Exif
            {
                ExifTag = CustomExifTags.ExposureTime,
                Show = true,
                Name = "ExposureTime",
                Id = (ushort)CustomExifTags.ExposureTime,
                ToString = value => ((double)value).DoubleToFraction()
            }
        };
    }

    public class Exif
    {
        public bool Show { get; set; }
        public ushort Id { get; set; }
        public string Name { get; set; }
        public CustomExifTags ExifTag { get; set; }

        public new Func<object, string> ToString { get; set; }
    }
}

gistfile2.cs

public enum CustomExifTags : ushort
{
    ImageWidth = 0x100,
    ImageLength = 0x101,

    Make = 0x10F,
    Model = 0x110,

    FocalLength = 0x920A,
    FNumber = 0x829D,
    ExposureTime = 0x829A,

    DateTime = 0x0132,
    DateTimeOriginal = 0x9003,
    DateTimeDigitized = 0x9004,
    ShutterSpeedValue = 0x9201,
    ApertureValue = 0x9202,
    LensModel=0xa434,
    ISOSpeed = 0x8833,
    TimeZoneOffset = 0x882A
}

gistfile3.cs

using (var reader = new ExifReader(propertyStream))
{
    foreach (var tag in ExifInfo.ExifTagsToCapture)
    {
        dynamic dynamicValue;

        if (reader.GetTagValue(tag.Id, out dynamicValue))
        {
            var value = tag.ToString((object) dynamicValue);

            photo.AddImageProperties(tag.Name, value);
        }
    }
}

gistfile4.txt

The result of this stored in the database:

"Properties": [
    {
        "Name": "Camera Make",
        "Value": "Canon",
        "Show": true
    },
    {
        "Name": "Camera Model",
        "Value": "Canon EOS 650D",
        "Show": true
    },
    {
        "Name": "Exposure Time",
        "Value": "1/80",
        "Show": true
    }
]