The Simplest (2 step) Roadmap for Processing Raw Images

Transcription

1 Fountain Hills Photography Club Information Series The Simplest (2 step) Roadmap for Processing Raw Images (An Exercise in Histogram Manipulation) (Appendix A has a 219 word explanation) December 12, 2018 Note : Camera settings and overall use of Adobe Photoshop and Luminar not included in these charts B.Boyce 12/12/18 1

2 Step 0. Raw, Unprocessed Image This is an example of successful capture of all image data of high dynamic range image within histogram Successful capture requires knowledge & use of the Histogram, Matrix Metering, Exposure Compensation, Raw data format, and Camera Mode 2

3 Step 1. Go into Camera Raw, do -100 Highlights, +100 Shadows, +.7 Exp (variable) To center histogram, concentrate on the histogram feet when adjusting Exposure This step uses Camera Raw H, S & Exposure (HS&E) sliders to manipulate (narrow & center) the histogram Exposure adjustment will vary from image to image 3

4 Step 1b. Go back into Camera Raw, do another -100 Highlights, +100 Shadows Second application of Highlight and Shadow sliders brings more detail from the wings of histogram into luminosity midrange by narrowing the histogram. Step 2 (next) eliminates any resulting haze in image This is an optional step, appropriate for high D.R. images. When in doubt, do it. If the sun is out, do it. 4

5 Step 2. After HS&E Processing, Enhance Contrast Initially set all sliders to 0 Move Correct Contrast slider first, then Dynamic Contrast slider You re Done! NIK Color Efex Pro 4 Pro Contrast Filter Correct Contrast adjusts overall image contrast Dynamic Contrast adjusts image detail contrast 5

6 Starting Raw Image Histogram Manipulation in Action Roadmap Step 2 Final Result Starting Raw Image Step 1 Result Step 1b Result Step 2 Result What Do We Get If We Apply an AI Filter? 6

7 Photoshop Camera Raw Auto Filter Only Result Camera Raw shows you where the sliders in the Develop Module go to when you select Auto If you don t like it, simply hit Default to undo result 7

8 Luminar Accent AI Filter Only Result Luminar does not show you where the sliders move to as a result of applying Luminar s Accent AI Filter There is a Boost slider that allows you to vary strength of effect 8

9 Look At Histograms Resulting From The Use Of AI Filters Only Camera Raw Auto AI Only Raw Image Luminar Accent AI Only HS&E + NIK Pro Contrast Not a whole lot of change in the Raw image histogram using only AI Now combine HS&E processing (HS&E first) with each of the 2 AI filters 9

10 HS&E + Camera Raw Auto Filter Result Any manual adjustments you make when you go into Camera Raw are ignored when you hit the Auto button Auto button is an All or Nothing result Hit Default to undo Auto results 10

11 Step 2. After HS&E Processing, Enhance Contrast Initially set all sliders to 0 Move Correct Contrast slider first, then Dynamic Contrast slider NIK Color Efex Pro 4 Pro Contrast Filter Correct Contrast adjusts overall image contrast Dynamic Contrast adjusts image detail contrast 11

12 HS&E + Luminar Accent AI Filter Result You may be able to use Luminar to do it all H, S & E sliders are in Luminar s Develop Filter Luminar also has a separate Highlights and Shadows Filter (found at the bottom of the list of available Filters) and Exposure Filter 12

13 Camera Raw Auto Only Conclusions Untouched Raw Image Luminar Accent AI Only HS&E + Camera Raw Auto HS&E + NIK Pro Contrast HS&E + Luminar Accent AI Starting out with Highlight, Shadow and Exposure sliders (HS&E) is key HS&E Pre-processes the image before invoking either an AI filter or NIK filter AI filters are not 1 Click solutions, just another tool in the toolkit All 3 approaches yield very similar histograms & image results (charts 10 12) I prefer the Baseline approach (HS&E + NIK) because the two contrast sliders in the NIK Pro Contrast Filter give me more control than either AI option 13

14 Summary of Raw Image Processing Roadmap Step 1 Use Highlights and Shadow sliders in Camera Raw to Narrow histogram, Exposure slider to center histogram (Maybe do this twice for sunlit and/or high DR images) Step 2 Enhance Contrast using an AI filter ( Auto in Adobe Camera Raw or Accent AI in Luminar, or use NIK Color Efex Pro 4 Pro Contrast Filter, or something else You re Done. 14

15 Appendix A - The Simplest Roadmap Explanation Step 1 Manipulate the Histogram Typical Dynamic Range (DR) of today s cameras is 8-10 stops or more A sunlit image containing bright clouds and shadows can easily exceed 8 stops DR Most images are good enough for human viewers when the dynamic range is 8 stops (1 bit = 1 stop = factor of 2) jpegs are 8 bit; print labs accept jpeg images for print as being good enough Thus, faced with a high DR image, one must narrow the histogram to reduce the image to a range of 8 stops As a benefit, more areas of the image will be brought into the midrange of luminosity where it is easier for people to perceive and appreciate image detail Best way to narrow the image histogram is to use the Highlight and Shadow sliders in either Adobe Camera Raw or Luminar (or many other programs) Step 2 Contrast Enhancement Use your favorite Contrast Enhancement tool to satisfy your artistic preferences These charts describe the use of one specific NIK Filter Or use one of the latest wave of processing developments based on Artificial Intelligence (Adobe Camera Raw Auto or Luminar Accent AI filter) The promise of One Click processing is overblown, but AI filters can have a significant role in post-processing (as just another tool in the toolkit) 15