Analogue to Digital

30th Sept. 2010

Reflections on this activityPlease answer the following questions on your wiki, before submitting the work.How appropriate is your choice of file format, resolution and size?What do you need to take into account when making these decisions?What does "size" mean in relation to a digital image?

There are a number of file formats/options available for use when creating a scan:

TIFF (Tagged Image File Format)PNG (Portable Network Graphics)JPEG or JFIF (Joint Photographic Experts Group File Interchange Format)GIF (Graphic Interchange Format)PDF (Portable Document Format/Adobe Acrobat File)PSD (Photoshop Document/Adobe Photoshop Image File)The camera's native RAW file

Generally speaking, for image scanning purposes the most widely used are TIFF’s and JPEG’s. TIFF’s allow the user to create large files containing detailed information, they are particularly useful when

looking to retain sharp contrasts and textural information. JPEG is the most common file format used with digital cameras and for web purposes. Although the format can

reproduce good tone and colour, it does not lend itself to repeated editing as the file deteriorates each time its modified.

If time allows, and you have the resource to save large files, the best option would be to scan large files to TIFF, edit, then re-save as smaller file or formats. It is also important to keep an original file.

Resolution will impact on visual quality and the amount of detail retained from the scanned object/material. Resolution of scanned images and camera generated images is measured in pixels or PPI, the more pixels the more quality and detail retained, but other factors should also be considered, quality of scanner/camera, quality/focal length of lens, interpolation, the qualities of the original scene or material, movement or vibration and contrast. If the captured or scanned image needs to be reproduced as hard copy, then printer resolution should also be taken into account, DPI (dots per inch), the higher the number of dots the better the quality of print. The larger the reproduction, the larger the original file needs to be, it is generally accepted that a DPI of between 240 and 300 provides an acceptable photographic quality at standard viewing distances, for web use 72 DPI is sufficient. The end use of your capture or scan will essentially dictate format and file size.

Epson V750 pro is a flat bed scanner with an A4 surface/document area, it includes transparency adaptors, film holders for individual and multi scanning and needs to be manually loaded. Scanning options include reflected image, transparency and negative. A preview button allows you to make sure the artifact is placed correctly in the scanner and to correctly frame the area to be scanned. Further refinements can be made in in the levels or curves to adjust colour, tone and contrast, as a general rule it’s advisable to try and retain detail in the highlight and shadow areas as this cannot be retrieved in post production.

Scanner vs camera there are a number of factors to consider when copying or reproducing images of objects/materials:

• Size of artifact/object, too large or too small• Format of artifact/object, 2D or shallow depth 3D• Damage to the artifact/damage to the scanner• Portability of objects/material or the scanner• Amount and format of objects/materials to be recorded• Size/availability of storage space

Scanned as negativeGlass negative (1/2 plate) this was the object used for the first scan and produced the first mistake, in

anticipation to see the image, I wrongly scanned it as a negative, which creates a positive and the negative itself is the object. The negative was sandwiched between two sheets of acetate to protect the scanner from scratches, it was scanned as a colour 24bit RGB, levels were used to help retain detail in highlight and shadow areas, it was scanned at 200% of its actual size at 300 dpi and saved as a Tiff.

No 24 Box C Mann Collection

Scanned as positiveGlass negative (1/2 plate) this time it was scanned correctly, as a positive which produced a transparent

negative. The negative was sandwiched between two sheets of acetate to protect the scanner from scratches, it was scanned as a colour 24bit RGB, levels were used to help retain detail in highlight and shadow areas, it was scanned at 200% of its actual size at 300 dpi and saved as a Tiff.

No24 Box 6 Mann Collection

Reflected image the next scan was essentially a flat copy, including image and text. The object was carefully placed upside down on the scanner bed, scanned as a colour 24bit RGB, levels were used to help retain detail in highlight and shadow areas, it was scanned at 200% of its actual size at 300 dpi and saved as a Tiff.

Reflected image the next scan was also a flat copy image with no text. The object was carefully placed upside down on the scanner bed, scanned as a colour 24bit RGB, levels were used to help retain detail in highlight and shadow areas, it was scanned at 200% of its actual size at 300 dpi and saved as a Tiff.

Colour transparency this was a 35mm mounted colour slide. It was carefully mounted in the transparency tray, it was selected individually, reframed, levels changed for colour and contrast, it was scanned at 500% to achieve a large enough file for an acceptable A4 print.

Colour transparency batch scan…