NCPS News

Jon Allanson presented this 3rd digital session. He based the evening on queries he had received whilst working at Jessops, and followed with comments around the subject of restoring badly mauled old prints.

Formatting was his first topic. He noted that a “cluster” (or allocation unit) is the smallest amount of disc space that an operating system can allocate to a file. Thus if the cluster is 32,768 bytes but the file is only 100 bytes the file uses up all the cluster. The next file starts at the next cluster. When files are deleted whole clusters become available for re-use. Large files will use the next available clusters, which may now be spread out over the disc. The FAT (file allocation table) is the index which records where the various bits are. A “quick format” removes this indexed data, allowing the clusters to be re-used but does not remove the actual data. (A full format apparently removes the data also!) A recovery programme is one that can read the clusters and record them as a new file number. In theory, it is then possible to reassemble the clusters into a meaningful file. Defragmenting the disc rewrites all the files, putting them on adjacent clusters and saving wasted space. Disc clean-up gives you the opportunity to remove temporary files clogging up the system..

Referring to raw vs jpeg files, Jon noted Raw files are unmanipulated, just as they were recorded by the sensor whereas, with jpeg, the camera has made assumptions (about colour temperature etc} and has sharpened the image.

Repeated saving of a jpeg file, as a jpeg file, continually degrades the image. He showed us images, which he felt had been so degraded, but since he didn’t show us the originals it was hard for the audience to get a feel for this. Jon showed a couple of A-V’s (using pictures-to-exe). Sadly the only sound came from the lap-top, and was inevitably rather tinny.

Restoring old photos relied on the dust and scratches filter, the clone tool and the patch tool. Old photos tended to have lost contrast and Jon used the dropper tools which accompany the levels histogram to restore the full tonal range.

Home News News Index Report About us Syllabus Exhibition Results Service Newsletter Galleries Links		3rd Digital Evening 6th December
		Jon Allanson presented this 3rd digital session. He based the evening on queries he had received whilst working at Jessops, and followed with comments around the subject of restoring badly mauled old prints. Formatting was his first topic. He noted that a “cluster” (or allocation unit) is the smallest amount of disc space that an operating system can allocate to a file. Thus if the cluster is 32,768 bytes but the file is only 100 bytes the file uses up all the cluster. The next file starts at the next cluster. When files are deleted whole clusters become available for re-use. Large files will use the next available clusters, which may now be spread out over the disc. The FAT (file allocation table) is the index which records where the various bits are. A “quick format” removes this indexed data, allowing the clusters to be re-used but does not remove the actual data. (A full format apparently removes the data also!) A recovery programme is one that can read the clusters and record them as a new file number. In theory, it is then possible to reassemble the clusters into a meaningful file. Defragmenting the disc rewrites all the files, putting them on adjacent clusters and saving wasted space. Disc clean-up gives you the opportunity to remove temporary files clogging up the system.. Referring to raw vs jpeg files, Jon noted Raw files are unmanipulated, just as they were recorded by the sensor whereas, with jpeg, the camera has made assumptions (about colour temperature etc} and has sharpened the image. Repeated saving of a jpeg file, as a jpeg file, continually degrades the image. He showed us images, which he felt had been so degraded, but since he didn’t show us the originals it was hard for the audience to get a feel for this. Jon showed a couple of A-V’s (using pictures-to-exe). Sadly the only sound came from the lap-top, and was inevitably rather tinny. Restoring old photos relied on the dust and scratches filter, the clone tool and the patch tool. Old photos tended to have lost contrast and Jon used the dropper tools which accompany the levels histogram to restore the full tonal range.
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