the last word

Photography meets digital computer technology. Photography wins -- most of the time.

  • site home
  • blog home
  • galleries
  • contact
  • underwater
  • the bleeding edge
You are here: Home / The Last Word / Testing for ETTR, part 21

Testing for ETTR, part 21

December 26, 2012 JimK Leave a Comment

Now we have two methods for UniWB that work just fine. One, the gridded search, requires only Rawdigger and Photoshop, and doesn’t make the user do any math beyond adding and subtracting integers. Newton’s method comes in two flavors. The simple monitor space approach takes a while to converge, but works well. The matrix-based camera space approach requires a spreadsheet to do the calculations, but converges fast. There’s a question as to whether the matrix that I came up with for the NEC PA301W and the D800E could be used for any monitor and camera. My guess is that it will provide faster convergence than plain monitor-space Newton’s method for almost all cameras and monitors.

Both the Newton’s method approaches can provide results whose accuracy is only limited by the repeatability of the screen shot numbers, which is better than the gridded search.

The Last Word

← Testing for ETTR, part 20 Testing for ETTR, part 22 →

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

September 2023
S M T W T F S
 12
3456789
10111213141516
17181920212223
24252627282930
« Jul    

Articles

  • About
    • Patents and papers about color
    • Who am I?
  • Good 35-70 MF lens
  • How to…
    • Backing up photographic images
    • How to change email providers
  • Lens screening testing
    • Equipment and Software
    • Examples
      • Bad and OK 200-600 at 600
      • Excellent 180-400 zoom
      • Fair 14-30mm zoom
      • Good 100-200 mm MF zoom
      • Good 100-400 zoom
      • Good 100mm lens on P1 P45+
      • Good 120mm MF lens
      • Good 18mm FF lens
      • Good 24-105 mm FF lens
      • Good 24-70 FF zoom
      • Good 35 mm FF lens
      • Good 60 mm lens on IQ3-100
      • Good 63 mm MF lens
      • Good 65 mm FF lens
      • Good 85 mm FF lens
      • Good and bad 25mm FF lenses
      • Good zoom at 24 mm
      • Marginal 18mm lens
      • Marginal 35mm FF lens
      • Mildly problematic 55 mm FF lens
      • OK 16-35mm zoom
      • OK 60mm lens on P1 P45+
      • OK Sony 600mm f/4
      • Pretty good 16-35 FF zoom
      • Pretty good 90mm FF lens
      • Problematic 400 mm FF lens
      • Tilted 20 mm f/1.8 FF lens
      • Tilted 30 mm MF lens
      • Tilted 50 mm FF lens
      • Two 15mm FF lenses
    • Found a problem – now what?
    • Goals for this test
    • Minimum target distances
      • MFT
      • APS-C
      • Full frame
      • Small medium format
    • Printable Siemens Star targets
    • Target size on sensor
      • MFT
      • APS-C
      • Full frame
      • Small medium format
    • Test instructions — postproduction
    • Test instructions — reading the images
    • Test instructions – capture
    • Theory of the test
    • What’s wrong with conventional lens screening?
  • Previsualization heresy
  • Privacy Policy
  • Recommended photographic web sites
  • Using in-camera histograms for ETTR
    • Acknowledgments
    • Why ETTR?
    • Normal in-camera histograms
    • Image processing for in-camera histograms
    • Making the in-camera histogram closely represent the raw histogram
    • Shortcuts to UniWB
    • Preparing for monitor-based UniWB
    • A one-step UniWB procedure
    • The math behind the one-step method
    • Iteration using Newton’s Method

Category List

Recent Comments

  • JimK on Backing up photographic images
  • Jeff Wolford on Backing up photographic images
  • Barry Goyette on My lack of productivity
  • JimK on Scanning black-and-white negatives with a GFX 100S
  • Andrew Freeman on Scanning black-and-white negatives with a GFX 100S
  • JimK on Sony a7RIV continuous drive mode precision
  • Richard Creamer on Sony a7RIV continuous drive mode precision
  • JimK on Smallrig L-bracket for Nikon Z9
  • Petert Orr on Smallrig L-bracket for Nikon Z9
  • Christian on How fast is the Z9 shutter?

Archives

Copyright © 2023 · Daily Dish Pro On Genesis Framework · WordPress · Log in

Unless otherwise noted, all images copyright Jim Kasson.