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You are here: Home / GFX 50S / Leica Q2 Monochrom vs GFX 50S — Siemens star

Leica Q2 Monochrom vs GFX 50S — Siemens star

May 14, 2022 JimK 3 Comments

This is the second post in a series about the Leica Q2 Monochrom. You can see all the other posts in the series by looking in the Category List drop-down menu on the right side of the page.

Aside from the one-stop increase in speed, which is undisputable, the putative advantage of monochrome capture is increased sharpness. I have not found that to be the case in previous testing, but I have noticed a reduction in aliasing. Now, with the Q2 Monochrom in hand, it was an obvious thing to test it against the Fuji GFX 50S, which has similar resolution. I used a Siemens start for the target, which is a cruel visual test for aliasing. If you’re going to see it, you’re going to see it with a Siemens star.

I compared the Q2, with its fixed 28mm lens, to the GFX 50S with a 45mm lens, adjusting the target distance slightly to get about the same target size in the image. Target distance wat about 15 feet.

The scene, with the Q2:

Q2 f/2.8

To get equivalent diffraction, I shot the Q2 at f/2.8 and f/4, and the GFX at f/4 and f/5.6.

The details:

  • Low-contrast sinusoidal Siemens star chart
  • RRS carbon fiber legs, Arca C1 head
  • Manual focusing with max enlargement and peaking
  • 4 shots at each condition, keep only the sharpest one.
  • 2-second self timer delay

Crops, at slightly greater than 100%, starting at f/2.8 for the Q2:

Q2 f/2.8

 

GFX f/4 color

 

 

GFX f/4 B&W

There’s a lot more aliasing in the GFX shot.

Now let’s look at f/4 and f/5.6:

Q2 f/4

 

GFX f/5.6 color

 

GFX f/5.6 B&W

Same general idea.

Lightroom has a demosaicing mode that they call Enhanced. Let’s see what that does for the GFX images.

Q2 f/2.8

 

GFX f/4 Enhanced

That’s a big improvement for aliasing, but some detail has been lost. The nod still goes to the Q2.

At f/4 and f/5.6:

Q2 f/4

 

GFX F5.6 enhanced

The Q2 image is definitely better.

Testing notes: It is really hard to focus the Q2 precisely using manual focusing. The first problem is that the helicoid is too fast. Little motion ofhte ring produces a large change in the focal plane. It shares this in common with most M-series lenses. The second issue is that the focus peaking has only one sensitivity setting,a nd that is way too high for this kind of work.

GFX 50S, Leica Q2 Monochrom

← Leica Q2 Monochrom OOBE Leica Q2 Monochrom vs GFX 50S — red Siemens star →

Comments

  1. James Sullivan says

    May 15, 2022 at 9:27 am

    The Q2 lens is focus-by-wire unlike M lenses. Although it is focus-by-wire, it still feels like a true manual focus lens. Spot AF or Field AF with the focus box adjusted to its smallest size on the Q2/Q2M is extremely accurate, unlike the AF of the 50S/R with GF lenses that seem to hit a different point of focus with every try, particularly at longer distances.

    Reply
    • JimK says

      May 15, 2022 at 9:42 am

      The Q2 lens is focus-by-wire unlike M lenses. Although it is focus-by-wire, it still feels like a true manual focus lens.

      It sure does. It’s way too twitchy. I don’t know how it could be FBW and have a mechanical distance scale, but I suppose that’s possible. The throw is only 90 degrees, which is about the same as the M lenses, and very fast for accurate work.

      Reply
    • JimK says

      May 15, 2022 at 9:44 am

      You’re experience with the GF lenses and AF is quite different from mine.

      https://blog.kasson.com/gfx-100/gfx-100-eye-detection-af-accuracy-numbers-and-samples/

      https://blog.kasson.com/gfx-100/gfx-100-af-s-and-af-c-accuracy-with-110-2-lens/

      https://blog.kasson.com/gfx-50s/gfx-af-accuracy-restated/

      Reply

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