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 / Lens screening testing / Examples / Good and bad 25mm FF lenses

Good and bad 25mm FF lenses

A reader sent me files from a Zeiss Batis 25 mm f/2 lens captured at f/4. The lens appears to be defective:

Batis 25 

You are looking at the nine captures, each magnified to double the approximate 200×200 pixel dimensions of the crops. I’ve arranged them in the same orientation as the original captures, with the image with the target in the center in the center, the image with the target in the upper right in the upper right, and so on.

It’s pretty obvious that the whole left side is soft. Whether you’d notice this in most real-world images, I can’t say, but if it were my lens, I’d send it back.

Note that we can’t tell if the issue is field tilt or something else based on the above set of captures.  For that, we’d need a set of  3 images on the left side focused there for each exposure.

Here’s another Batis 25:

This one appears to be fine.

April 2021
S M T W T F S
 123
45678910
11121314151617
18192021222324
252627282930  
« Mar    

Articles

  • About
    • Patents and papers about color
    • Who am I?
  • 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 Relative sensitivity of Sony a7RIV and GFX 100S
  • Anu on Relative sensitivity of Sony a7RIV and GFX 100S
  • JimK on Relative sensitivity of Sony a7RIV and GFX 100S
  • CarVac on Relative sensitivity of Sony a7RIV and GFX 100S
  • JimK on Relative sensitivity of Sony a7RIV and GFX 100S
  • Ilya Zakharevich on Pixel shift with the Fujifilm GFX 100S
  • Ilya Zakharevich on Relative sensitivity of Sony a7RIV and GFX 100S
  • JimK on GFX 100S sensor is a 4-shot stitch
  • John Leathwick on GFX 100S sensor is a 4-shot stitch
  • Christer Almqvist on GFX 100S sensor is a 4-shot stitch

Archives

Unless otherwise noted, all images copyright Jim Kasson.