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 / 2015 / August / Archives for 8th

Archives for August 8, 2015

Sony a7R, a7RII shutter shock with 180/3.4

August 8, 2015 JimK 5 Comments

The mechanical shutter on the Sony a7RII is supposed to be better damped. It also has electronic first-curtain shutter (EFCS). How do those things make moderate telephoto pictures sharper? The protocol: The cameras: the Sony a7RII and Sony a7R. The lens: the Leica 180mm f/3.4 Apo-Telyt-R The filter: Heliopan 77mm variable neutral density. The lighting: a… [Read More]

The Last Word

a7RII bulb mode spatial filtering at ISO 100, 400, & 1600

August 8, 2015 JimK 2 Comments

I was asked if the spatial filtering mentioned in the previous post that takes place in bulb mode at ISO 6400 also happens at other ISOs. I tested three of them. It looks like the filtering is nonlinear, since it has different effects at the different read noise levels of different ISOs. I assume, but… [Read More]

The Last Word

Sony a7RII bulb spatial filtering

August 8, 2015 JimK 2 Comments

The other alpha 7 cameras switch from 13-bit to 12-bit precision when the shutter is set to bulb, even if the shutter mode is single shot. Is that the case with the a7RII? Yes, indeed. Here’s the histogram of a 6-second single shot, ISO 6400, dark-field exposure made using the camera’s shutter timing mechanism: Every… [Read More]

The Last Word

August 2015
S M T W T F S
 1
2345678
9101112131415
16171819202122
23242526272829
3031  
« Jul   Sep »

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 Sony 135 STF on GFX-50R, sharpness
  • K on Sony 135 STF on GFX-50R, sharpness
  • Mal Paso on Christmas tree light bokeh with the XCD 38V on the X2D
  • Sebastian on More on tilted adapters
  • JimK on On microlens size in the GFX 100 and GFX 50R/S
  • Kyle Krug on On microlens size in the GFX 100 and GFX 50R/S
  • JimK on Hasselblad X2D electronic shutter scan time
  • Jake on Hasselblad X2D electronic shutter scan time
  • Piotr Chylarecki on Who am I?
  • JimK on Who am I?

Archives

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

Unless otherwise noted, all images copyright Jim Kasson.