Clive R. Haynes FRPS
See also 'link' to Digital Workflow chart at base of this page
How big an original image do you need?
the picture to be used for:
File Size for Photographic Quality
make prints of 'photographic quality' the image need to have sufficient resolution.
Note: 200ppi is fine for 'photographic resolution' and making a print via an ink-jet printer. A commercial printer may request 300ppi as this resolution suits their processes.
For Archival Purpose:
Retain the file at the largest size practicable as who knows for what purpose the image may be used one day?
the Internet / Web
The sizes above will fit on almost any monitor screen and will load quickly (dependent upon modem / connection speed)
Whether you are using a camera or scanner it's important that the file size you produce will be suitable for your purpose.
Film Camera: 35mm is generally good. Larger formats will allow bigger enlargements.
Digital Camera: A 6-megapixel camera will be able to produce an acceptable image up to A3 in size from the full frame.
The more 'megapixels' the camera has the larger the resulting image can be. Most cameras quote 'megapixels per channel' (though this isn't always stated). As the camera will have three channels (red, green & blue) the number of megapixels needs to be multiplied by three. So a 6-megapixel camera will produce a file size of around 18 megapixels (or 18mb) - this is close to 20mb so a satisfactory A3 picture should result.
Cameras with less than 6 megapixels will produce correspondingly smaller file sizes and hence smaller pictures with acceptable resolution.
Type (digital cameras only):
Good Practice for Quality:
For copying, use a 'copy stand' with even lighting over the work
/ Positive (Transparency / Slide film) Scanners
Image Management Program / Software
are many programs available.
Back-up and Back-up again
The need to 'back-up' cannot be too strongly emphasised. Hard disks can fail.
Back-up to CD or DVD and/or to an external drive unit. It's also possible to back-up to 'virtual archives' on the Internet.
to Home Ink-Jet Printer
To achieve consistent quality of printing 'computer / monitor calibration' and 'paper / printer profiling' will give more certainty of printing accurately what you see on the monitor screen.
Different monitors display colours differently - monitor calibration will set the monitor to a known standard. Native Digital Ltd. of Solihull offers this service.
Different papers will print differently (different origins, coating, qualities, base colours, reflective indices, etc). Each paper should be 'profiled' in conjunction with the specific printer being used. Photo-quality paper supplier, Permajet Ltd., of Warwick, also offers a 'profiling service'. Use a quality paper for consistent results, preferably of 'acid free, archival' specification.
Use either original manufacturers inks or a known high-quality alternative (Permajet for example), Ink-jet printers can use either 'dye inks' or 'pigment inks'. Dye inks are not as archivally permanent as pigment inks. Quality pigment inks with suitable high quality, acid-free, paper and proper storage can offer life times of around 100 years.
Bureau / Picture Library
If you wish to send your images to a 'bureau', such as a picture library or professional printing service, ask for details about the file size and resolution they need.
Colour slides continue to be easy to use and project well.
Digital files need to be managed correctly and saved in an easily readable format, 'jpeg' for example. The image needs to be of sufficient size for good definition but not too large, otherwise loading times will be lengthy. For most current data-projectors, images sized to 1024 x 768 pixels should be satisfactory.
Digital images can be assembled as a 'presentation' by using a program such as Microsoft 'Powerpoint'. However, more sophisticated programs enable more professional-looking audio-visual presentations to be made. Popular digital A-V programs such as 'Pictures to Exe' and 'Pro Show Gold' are readily available.
Stability of Media - the Great Unknown
An unknown factor remains the longevity of digital storage media. How long can a disk be stored, will it degrade? How reliable is an Internet archive? What new formats will supersede the existing ones? Will a file saved now be readable in 100 years?
Consider this, who can now replay a gramophone cylinder recording, a 78 rpm record, a 33 rpm 'long player', a reel-to-reel audio tape, an eight-track audio cassette, a 'Betamax' video tape, 'Standard 8mm' or 'Super 8mm' movie film? All these represented 'acceptable formats' in the recent past.
To maintain pace with the rapid development curve of digital media we will need to copy our precious files time and again, upgrading to the latest format and trusting that future generations will maintain this duty.
More information about Workflow
Click this link for
Photoshop Workflow Practice
Photo-Quality Papers & Profiling: Permajet Ltd (Warwick):
Calibration: Native Digital Ltd (Solihull):
Photographic Society, Digital Imaging Group:
- scroll to base of page
Midlands Digital Imaging Group:
camera clubs and photographic societies have wide-ranging membership and can offer
friendly, helpful advice at an easy accessible level one such club is
Extra: Digital Workflow Flow chart - Click on the link belowto view
(printable version to 'download' also available)