Digital Workflow
Considerations & Fundamentals

Clive R. Haynes FRPS

 
See also 'link' to Digital Workflow chart at base of this page
 

Image Capture
Before pressing the button, consider what the picture is to be used for. The decision made at this stage will influence the quality of the final result.

How big an original image do you need?

Is the picture to be used for:
A print - if so what size?
Long-term archival storage with no firm intentions at this stage
The Internet / Web
Projection (slide or digital)

 

File Size for Photographic Quality

To make prints of 'photographic quality' the image need to have sufficient resolution.
The guide below represents the minimum file size for a (8 bit) colour picture at a resolution of 200ppi:

A2 = 40mb
A3 = 20mb
A4 = 10mb
A5 = 5mb
A6 = 2.5mb

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?

For the Internet / Web
Generally, the file sizes for display via the Internet are small, I suggest these settings:

Resolution: 72ppi
600 pixels width for a horizontal image
500 pixels height for a vertical image

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.

 

Camera Choice

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.

File Type (digital cameras only):
'Camera RAW' files are superior to high-quality JPEG files but not every camera will have this facility. You also need to have an imaging program that will 'read' RAW files.

White Balance:
For digital cameras this function is usually automatic, however if you are in doubt about your camera's ability to record the colours accurately, whether film or digital, place a white and/or a mid-grey card somewhere within the scene. Take one shot as a reference with the card(s) in place and then a picture without. The first shot is the 'reference picture': the second, is the 'working picture'. This simple practice can help you make colour corrections later, reducing or eliminating a colour cast.

 
 

General Good Practice for Quality:

Use a tripod or monopod

For copying, use a 'copy stand' with even lighting over the work

Film Camera:
Use the slowest film that is sensible for the subject and conditions.

Digital Camera:
Set the camera to the lowest ISO setting that is sensible for the subject and conditions.

 

Scanners:

Flatbed Scanners
These scan reflective material (like a photocopier). They are excellent for copying prints and documents (even small three-dimensional objects). Some flatbed scanners incorporate a 'trannie-hood'. With this device large format negatives and transparencies may be scanned. 35mm film scanning with a 'hood' is possible but with variable quality.

Negative / Positive (Transparency / Slide film) Scanners
These are more expensive than flatbed scanners but they are dedicated for the specific task. The file size guide given earlier applies for optimum results.

 

Image Management Program / Software

There are many programs available.
Adobe Photoshop is the market leader and the program of choice.
'Lightroom', a new product from Adobe, is soon to be available.
Adobe 'Elements' is a good second choice.
'Paintshop Pro' is another (low cost) option.

 
 

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.

 

Output to Home Ink-Jet Printer

Printer resolution for photographic quality should be set to 1440 dpi (dots per inch). Do not use less than 720 dpi.

For best results your system should be both 'calibrated' and 'profiled'.

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.

 

Projected Images

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
 

Helpful References

Photo-Quality Papers & Profiling: Permajet Ltd (Warwick):
www.Permajet.com

Monitor Calibration: Native Digital Ltd (Solihull):
www.nativedigital.co.uk

Royal Photographic Society:
www.rps.org

Royal Photographic Society, Digital Imaging Group: - scroll to base of page
and in 'Choose A Group', Select: Digital Imaging

RPS Midlands Digital Imaging Group:
www.midig.org

Local camera clubs and photographic societies have wide-ranging membership and can offer friendly, helpful advice at an easy accessible level one such club is
Worcestershire Camera Club:
www.worcestershirecameraclub.co.uk
There should be a similar club or society somewhere in your area

 
Extra: Digital Workflow Flow chart - Click on the link belowto view
(printable version to 'download' also available)
Flow Chart
 

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