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 / GFX 50S / Fuji 110/2, 120/4, Zeiss 135/2 OOF PSFs

Fuji 110/2, 120/4, Zeiss 135/2 OOF PSFs

July 9, 2017 JimK Leave a Comment

This is the 70th in a series of posts on the Fujifilm GFX-50S. The series starts here. 

For the nonce, I’m done with my little sprint of evaluating the Sony 12-24. I’ll return to the work I was doing on the Fuji 110/2 and the 23/4 on the GFX. Today’s post is about bokeh, and it’s about the 110. I’ll throw in a couple of comparison lenses, the Fuji 120/4 and the Zeiss 135mm f/2 Apo Sonnar ZF.2, a full frame lens that does very well on the GFX.

There are two pieces to bokeh. The first is what things look like when they are well out of focus (OOF), and the second is how the transition from OOF to in-focus happens. The second is complicated, but the first is very simple. What you see when part of the image is well OOF is each point in the image times the OOF point spread function (PSF, in this case, aka bokeh balls). So you can understand what the bokeh in the OOF regions is gonna look like by looking at the OOF PSF across the frame.  After you’ve looked at a few of these images that I’m going to show you today, you can see how the deep-OOF bokeh of just about any lens is going to look like with just about any scene. 

The technique that I used to obtain the images below is explained here.  I just moved the camera around and captured the PSFs all over the frame, then assembled them in Photoshop.

Here’s what the 110/2 looks like wide open:

 

In a perfect world, all the balls would be round and constant intensity, with no colors off the gray axis. Hardly any lens can do that wide open. The 110 has a nice flat center disc, and only moderate occlusion as you progress towards the periphery. Good work, Fuji.

 

Now, the 120 mm, also wide open:

We actually see more occlusion, even though the 120 is two stops slower than the 110. This isn’t bad, but you can tell that bokeh was not the primary objective when Fuji designed this lens. The disks are flat and unchromatic. 

 

Next I’m going to show you the Apo Sonnar wide open. This isn’t fair to Zeiss, because this lens was designed for a full frame camera, and we’re going to look at it much further off axis than you could get with, say, an a7RII. 

 

As you can see, The Apo Sonnar doesn’t do as well and either of the other two lenses, but the disks look good if you forget about the occlusion. 

To see what some really (and intentionally) odd OOF PSFs look like, consider these from a Petzval 58/1.9:

 

 

 

GFX 50S, The Last Word

← Sony 12-24 f/4 OOF PSFs Sony 12-24 LoCA & focus shift at 18 & 24 mm →

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.