Theory of Practice: Technical Papers

This page lists a series of short papers, videos, and test files abridged from our courses and workshops covering some of the questions we are most commonly asked. Movie downloads are MPEG files that can be viewed in most video players, and our course notes require a PDF Reader such as Adobe AcrobatUpdated 01 January 2021.

Left Click on each link to access the file in a new browser window (zipped folders can’t be previewed) where y0u can Download it directly from our DropBox  (i.e. in the browser window’s top right corner select Download/Direct download).

Are you Seeing Correct Colour?
A simple outline of two basic evaluations anyone can undertake to help them understand why their prints do not match their screen and why Adobe Photoshop or Lightroom soft proofing does not work. Last updated 28 July 2019.

Matching Prints to Screen – An Introduction:
An introduction to the resources on this page that address the challenge of matching prints to their screen appearance. Use this short paper as both an index and road-map in the evaluation of your own working environment and print to screen matching. Last updated 20 April 2020.

•  Introduction to Monitor Calibration:
A brief overview of monitor calibration with initial recommendations for ISO compliant calibrations and the circumstances and workflows they apply to. Last updated 09 January 2020.

• Monitor Calibration for Screen Based Workflows:
A short paper that addresses the question: How do I know whether my image will appear the same on a different monitor? Through the identification and reduction of errors and inconsistencies, confidence but not certainty, can be restored to screen based workflows. Last updated 09 January 2020.

•  Monitor Theory: 
A short paper on the theory and practice of monitor calibration for fine art photography. Last updated 21 October 2018.

• Lighting Theory:
A short paper on the theory and practice of how to create a critical print viewing environment for accurate soft proofing. Last updated 19 September 2020.

How to Soft Proof:
An introductory essay comparing Application Proofing in colour savvy software compared with Screen Simulations on advanced graphics monitors. Last updated 24 July 2021.

• Soft Proofing Theory:
An outline of the theoretical factors determining the limits of soft-proofing simulations with workflow solutions to the most common errors and misunderstandings. Last updated 19 October 2020.

Soft Proofing Practice:
This paper discusses the ‘difficulty’ posed by the fluorescence from optically brightened printing papers for accurate soft proofing.  While this ‘difficulty’ can be resolved, its solution requires a far more rigorous practice compared with soft proofing traditional non-OBA enhanced papers. Last updated 18 December 2020.

Photoshop Hard Proofing for Printing with Pro Labs:
This paper details the production of accurate small format ‘Guide Prints’ to assist your digital file’s faithful large format printing by a ProLab or Boutique Printer. Last updated 28 March 2021.

• Calibrating Dual Screens:
A short paper on the considerations, limitations and best practices associated with matching images across multiple screens. Last updated 09 January 2020. 

Basic Monitor Calibration Video (ISO3664):
A five minute video illustrating how to create a new EIZO ColorNavigator calibration target that is ISO 3664 compliant for general photo editing.  Last updated 28 May 2015.

Advanced Soft Proofing Monitor Calibration Video:
A five minute video illustrating how to precisely adjust the monitor’s appearance in order to achieve a more accurate visual match between the appearance of the image on screen and as a print. Last updated 04 April 2017.

Advanced Soft Proofing Monitor Calibration Video Transcription:
I have also provided the script for this video as it tends to be less distracting and easier to follow written instructions than trying to simultaneously calibrate your monitor while watching the video.  Last updated 31 March 2017.

• ColorChecker_24 step_AdobeRGB Target: 
A printable version of my Gretag Macbeth  24 Step Color Checker in the Adobe RGB (1998) colour space. Print this file, and under your standard print viewing conditions and light source compare the print with its screen rendering. In an accurately profiled soft proofing workflow there should be a very high correlation between the print and screen renderings.

• ColorChecker_24 step_sRGB Target: 
A screen version of my Gretag Macbeth  24 Step Color Checker in the sRGB IEC61966-2.1 colour space. Use this file to compare renderings across multiple monitors in a screen based workflow (such as for web development). In an accurately profiled workflow there should be a very high correlation between the rendering of this target on all screens.

White Point Luminance Target:
A 255R 255G 255B file for setting the monitor white point in applications like Adobe Lightroom that can only import files, not create them. Use for matching the screen white point with your printing paper’s white point as illustrated in our Advanced Soft Proofing Monitor Calibration Video. 

• Ambient Lighting Evaluation Target:
A mid-grey L*50 file for evaluating and setting surrounding ambient illumination in screen based colour critical editing environments. When matte paper-white matches L*50 mid-grey on an 80cd/m^2  peak brightness monitor screen the ambient illumination will be close to the ISO3664:2009 recommendation of ≤ 32LUX. 

• Light-Dark Levels Printing Target: 
A target for testing the correlation between screen and print appearance. All L* values from 1 to 30 and 70 to 99 should be equally visible on screen and in print in an accurately profiled workflow without compromising the maximum possible print density (i.e. black).

Neutral 256 Step Wedge:
This file encompasses 256 evenly distributed brightness levels without dithering (noise) for evaluation of the gradation smoothness and neutrality of monitor and printer profiles. 

Why Les Walkling & Co. Custom Printer Profiles?
A detailed analysis of the ‘difficulties’ experienced when printing with generic printer profiles, and how we correct this, not just through custom profiling specific printers and workflows, but the profound improvements our skills and profile enhancements make.  Last updated 02 August 2021.

Profile Variants:
An outline and explanation of the different printer profile variants we create, their purposes, both technically and aesthetically, and recommendations for their application in print production workflows.  Last updated 02 May 2021.

Evaluating Media:
Includes various approaches to making sample prints for direct media comparison and evaluation, including our custom service where we print a supplied test image via our custom profiled workflow on either an Epson SureColor, Epson Stylus Pro, or Canon Pro printer and the different media under evaluation. This is a cost-effective approach supporting the accurate comparison and evaluation of different media without initially incurring the expense of custom profiles for every media under investigation.  Last updated 06 April 2020.

3DLUT Creator Teaser Movie URL:
A link to our YouTube Channel and video introduction to 3DLUT Creator. Though this brief look at 3DLUT Creator ‘barely scratches the surface’ of its immense possibilities, profoundly creative controls, and stunning originality, I hope it is sufficient to intrigue and encourage you to explore 3DLUT Creator, as well as contextualise ‘Photoshop’ and the ‘thinking’ behind similar applications as aberrations rather than ‘correct practice’, and their many conflicts and contradictions as exceptions rather than the norm. Last updated 21 November 2018.

3DLUT Creator Fundamentals:
Summarises approaches to localised image editing (selections, masks, and nodes) and 3DLUT Creator’s extraordinary facility of grid and curve nodes, along with the fundamental tasks of selecting, pinning and editing nodes with workflow shortcuts and processing priorities. Last updated 13 December 2020.

•  Live Picture:
My original Live Picture workshop notes (last revised 2005). Live Picture is a resolution independent real-time imaging program that runs under the Macintosh 
Classic operating system. Though Live Picture was commercially discontinued in December 1999 I continue to use it as one of my primary image editing programs. Last updated 28 November 2007.

Understanding Pictures:
A brief summary from my Understanding Pictures workshop covering those pictorial design questions that also get asked in many of my other workshops – from Digital Printing to our Photoshop Master Class. Last updated 27 July 2020.

•  On Print Luminosity:
Notes from 1980 on the contribution of subjects-that-matter, structures, luminosity, and foundations on a print’s emanating presence. Last updated 24 May 2014.

• My Emotional Theory of Print Size:
A short paper from 1985 outlining the relationship between the relative scale of my prints to their subject-that-matters.  Last updated 22 February 2016.

• My Emotional Theory of Aspect Ratios:
An update of my original 1985 paper that outlines my understanding of how the ratio of height to width in a print effects our interpretation of it. Last updated 18 May 2016.

Camera Profiling:
A discussion of the methodology, workflow and colorimetric advantages of custom calibration and profiling of Hasselblad H System cameras. Last updated 02 March 2020.

Notes on Reprographic Photography:
A collection of recommendations and observations on the digitising of cultural and biological collections, including quality control, verification, camera alignment, lighting, diffraction, and depth of field considerations. Last updated 03 December 2018.

In-House Hard Proofing Made Easy:
A short paper on easy and affordable in-house hard proofing that exceeds FOGRA standards via the RGB Mirage RIP.  Last updated 21 September 2020.

Controlling Inkjet Printers for ‘Alternate Processes’:
A short paper on creating custom ink profiles for use with Roy Harrington’s QuadToneRIP to better align an Epson printer’s output to the requirements of ‘alternate processes’ such as printing on photopolymer Photo Gravure plates. Last updated 07 May 2015.

B&W Film Calibration Data:
This paper outlines my current calibration data for the safe non-staining development of B&W film destined for scanning without sacrificing the beautifully detailed translucent highlights, lively shadow separation, and edge enhancement my ‘Pyro’ staining (tanning) film developers achieved in silver gelatin darkroom prints. Last updated 10 July 2020.

•  B&W Contrast Filters:
The calculation of digital equivalents to Kodak’s Wratten Filters and their implementation in preparing digital B&W fine prints. Last updated 13 June 2020.

•  Editing Out-of-Gamut Colours:
A Photoshop 
L*a*b* method for the local perceptual compression of Relative Colorimetric (B2A1) ‘out-of-gamut’ transformations. Last updated 11 December 2006.

•  Luminosity Mapping:
The conversion of multi-channel images to a single greyscale channel is based on a luminosity formula, which in turn is based on a theory of perception. This paper examines Photoshop’s methodology and why desaturation and other conversion formulae do not always produce a satisfactory perceptual result. Last updated 24 May 2014.

•  Toning B&W Digital Images:
A luminosity masking method for toning digital images so as to emulate the ‘look, feel and presence’ of toned silver gelatin fine prints. Last updated 03 August 2015.