End-to-End Calibration 101. Sept 2015 Rob Redford

Transcription

1 End-to-End Calibration 101 Sept 2015 Rob Redford

2 End-to-End Calibration Calibration involves setting up all of the hardware and software in your workflow to ensure consistency and accuracy throughout the entire process, end-to-end Develop a plan for calibrating your equipment Things to consider Deciding what to calibrate: expected return? Tools and process Mostly about maintaining color accuracy. This will NOT happen on its own! This presentation will point you in the right direction but is not a tutorial Resources and links: see Calibration page on Meetup Pages tab Calibration will not make a bad picture good, but it will make a good picture better Decide which steps are worth it to you, but all of these steps are recommended

3 Why Calibrate? Achieve what you envisioned when you captured your image with less effort Lots of hardware & software in your workflow: Different defaults, settings Undesired conversions or other changes are happening without you knowing Color shifts are almost impossible to notice unless observed side-by-side It s not hard and only need to be done occasionally Just because you don t see the discrepancies

4 Test Your Color Perception Online color perception test: Note: calibrate your monitor first!!

5 Test Your Color Perception

6 End to End Calibration Camera Monitor Software Printer/Paper Autofocus Color space Color profile Color profile Color space Gamma Brightness Contrast Ambient lighting Color space Camera profiles White balance Soft proofing File formats Paper Digital images Paper/printer profiles Color management Note: All listed online resources can be found on the Calibration page on our club Meetup Pages tab.

7 Camera Calibration Autofocus Make sure what you focus on is actually in focus The default settings may be off and should be checked and calibrated Color Space Make sure your camera s color space is set to AdobeRGB and not srgb, which has a smaller gamut Color For maximum accuracy, create a camera-specific color profile Can create different profiles for different lighting situations

8 Camera Calibration: Autofocus Simple, free tools available on the web Idea is to shoot a chart with calibration marks to indicate where your autofocus system is actually focusing Test all your lenses may vary by lens Resources: The above file contains the tutorial, instructions, and the calibration chart Based on a Nikon D70 but you can adapt it on your own

9 Camera Calibration: Autofocus

10 Camera Calibration: Color Profile Shoot a color calibration chart and use supplied software tools to create a DNG color profile specific to your camera Keep the chart in your camera bag - especially useful for unusual lighting situations Resources: X-Rite ColorChecker Passport on amazon.com

11 Camera Calibration: Color Profile Lightroom Example 1. Shoot swatch under desired lighting conditions (illuminant) 2. Check histogram to ensure proper exposure 3. File>Export with Preset>ColorChecker Passport. Creates and installs a DNG profile for your camera 4. Choose the camera profile under the Camera Calibration menu in the Develop module.

12 Monitor Calibration The most important adjustment to make If your monitor is not color accurate everything you do to your image is inaccurate Most monitors have significant color casts out of the box, even if you use built-in color profiles Requires a colorimeter and accompanying software to create a monitor-specific color profile If you use more than one monitor, calibrate each one separately Ensure your calibration software supports more than one monitor (e.g. Datacolor Spyder Express products do not)

13 Monitor Calibration The software takes you through the process of setting gamut, gamma, brightness, and contrast hardware controls Creates an ICC color profile for your monitor and loads this at startup A number of people in the club have colorimeters and may be willing to calibrate your monitor for a free lunch, beer, etc!

14 Monitor Calibration Chart shows your monitor s gamut coverage Compare to AdobeRGB

15 Monitor Calibration: Software Colorimeters come with software utilities, but you can also use some open source applications: ArgyllCMS is an ICC compatible color management system. It supports ICC profile creation for scanners, cameras and film recorders, and calibration and profiling of displays and RGB & CMYK printers DispcalGUI is a graphical user interface for the display calibration and profiling tools of Argyll CMS dispcalgui.hoech.net

16 Software Calibration Your post-processing software does not require calibration per-se, but you do need to ensure your preferences are set to your calibrated values Things to check: External editing settings (color space, bit depth, file format) are optimal and the same in each application Camera color profiles installed & selected Paper/printer color profiles installed & selected White balance set properly Monitor color profiles installed & in use

17 Software Calibration The Xrite ColorChecker can also be used to set the white balance accurately for your image (situational lighting) Neutral White Balance < Warmer Cooler > Select a square with a dimple using the white balance sample tool

18 Ensure All Profiles Are Selected Develop Module Print Module

19 Printer/Paper ICC Profiles Specific to the printer and paper combination. Choose paper manufacturers that supply a full set of color profiles.

20 Printing/Exporting Printing workflow: 1. Select your paper/printer ICC profile 2. Do a Soft Proof to ensure colors are not out of gamut. Manually correct or accept defaults. 3. Enable color management in your software application 4. Ensure that color management is OFF in your printer driver(!) If exporting an image to a JPEG file, select the srgb color space for most situations (this is the default on the web).

21 Soft Proofing Out of gamut warnings

22 Printing/Exporting Printing Exporting to JPEG

23 Disable Printer Color Management

24 Questions? Be sure to use the monthly mentoring sessions before the meeting to get help with any of these or other topics. We re here to help!