the up stream approach to gunthorpe lock
{"Image Make": "Canon", "Image Model": "Canon EOS DIGITAL REBEL XT", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS2 Macintosh", "Image DateTime": "2009:07:11 10:55:41", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "236", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "1062", "Thumbnail JPEGInterchangeFormatLength": "6872", "EXIF ExposureTime": "1/80", "EXIF FNumber": "10", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "200", "EXIF ExifVersion": "", "EXIF DateTimeOriginal": "2009:07:10 19:24:58", "EXIF DateTimeDigitized": "2009:07:10 19:24:58", "EXIF ComponentsConfiguration": "", "EXIF ShutterSpeedValue": "207157/32768", "EXIF ApertureValue": "108853/16384", "EXIF ExposureBiasValue": "0", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "18", "EXIF FlashPixVersion": "", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "640", "EXIF ExifImageLength": "427", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[0, 0, 0, 0]", "EXIF InteroperabilityOffset": "936", "EXIF FocalPlaneXResolution": "1728000/437", "EXIF FocalPlaneYResolution": "384000/97", "EXIF FocalPlaneResolutionUnit": "2", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard"}