I had the good fortune to be able to borrow for about 20 minutes a brand new Fuji GFX100RF. What a beautiful camera Fuji has made. I'd be thrilled to own one. Yes, even if it is fixed lens, bigger than anything I currently own, and comes with a confusing array of knobs, dials, and buttons. I'd adapt. Really. I could.
Reading the marketing literature and camera reviews I expected to see "better" performance of some kind or other out of this new Fuji over, say, any Full Frame or APS-C device. Bigger is better, right? How could it not be?
More specifically, I was curious to see how the Fuji with a larger than Full Frame sensor would behave vis a vis a Digital Zone System tonal values as I've come to understand them and to see how Fuji implemented their in-camera jpg engine. I put the camera through its paces. I started by looking at the default Black and White creative style and then turned my attention to Fuji's Acros in-camera "film simulation".
Here's what I found.
Comments ~
Comparing the default Black and White Fuji output against the 1EV per Zone standard I see that Zone 5/0EV is very close to the #76 luminosity 18% black standard. The blacks drop off a bit quicker than the 1EV per Zone standard, but compared against the Zone System tonal range of my Sony A6300 APS-C + DRO1 I see the Fuji has a broader range of tones in the dark areas. Highlights are nearly, but not quite identical between the "ideal", the Sony A6300 recipe and this Fuji. The Fuji produces a brighter Zone 8. Further, in practice I would expect the Fuji GFX100RF to offer up an "open" range of shadow tones over the Sony recipe.
As a side note, Sony RAW delivers very good tonal separation in the dark tones that are not expressed when using the in-camera jpg processor EXMOR and EXMOR R versions of the ASIC. It seems that Sony made a conscious choice about how the dark tones are handled. There's nothing wrong with their decision as far as I'm concerned. It's just something to know and work with. In my own work I mitigate the steep dark tone drop-off of the default B&W setting by adding DRO1, which brings up the shadows to the degree I prefer. Fuji doesn't seem to require this kind of massaging by default.
Looking at the Acros "film simulation" at default settings I see the entire tonal range is brought down to various degrees compared with the standard. Perhaps this is what Fuji feels could give a sense of "richness" when using this style? In any event, I feel the Acros setting simply produces a darker B&W image in camera.
I verified that the Fuji GFX100RF has a "spot" meter selection and that buttons are customizable for AEL lock. So, just as with Sony upon which I developed the details of this Digital Zone System, the medium format Fuji appears to provide a decent platform for in-camera jpg Zone System tonal range management. The "goodness" being, if I were wealthy enough to afford a Fuji in the first place, I would know exactly where to place the various tones of a scene.
------------- References From Prior Posts ---------------
Zone System Definition ~
- Zones are separated by 1 f-stop/1 Exposure Value (EV)
- Zone 5 ~
- old film days == 18% gray
- digital tone value == #76(hexidecimal)/118(decimal)
- Pure Black
- old film days == Zone 0 at -5EV
- digital tone values == -EV-whatever the camera system can deliver (commonly different between RAW - ideally -10EV!!! and the in-camera jpg generator - Sony Creative Style Black and White in-camera seems set at -5EV, Fuji's GFX isn't demonstrably different from this)
- Pure White
- old film days == Zone 10 (last definition) or Zone 9 (earlier definition)
- digital tone value == +4EV as Zone 9 for the Sony cameras I own (this has been measured and is very important! to successfully using the Zone System in digital)
Digital Zone System In-Camera jpg Step Wedge generation ~
To evaluate in-camera jpg generation here's the method I used to create a Step Wedge that I could visually inspect to when making various in-camera parameter changes -
- Camera settings -
- ISO == 100
- Creative Style B&W
- B&W Contrast to a test value - I've tried -3 to +1
- Dynamic Range Optimization - Off or DROx where x == [1, 2, 3]
- Meter to Spot
- Output file == jpg
- Manual focus and defocus the lens as much as possible to fully blur the scene (wanting just tone, no texture)
- Using an evenly lit surface (piece of paper, wall, etc)...
- Take two photos at 0EV and verify which 0EV setting gives exactly #76/118(dec) in the center (where the Spot meter metered) by measuring the tonal value using an image processing software on a computer. This will be Zone 5 per definition.
- Raise EV by 1EV
- Take a photo
- Measure and note as Zone 6 the tonal value as read on a computer
- Raise EV by 1EV
- Take a photo
- Measure and note as Zone 7 the tonal value as read on a computer
- Raise EV by 1EV
- Take a photo
- Measure and note as Zone 8 the tonal value as read on a computer
- Raise EV by 1EV
- Take a photo
- Measure and note as Zone 9 the tonal value as read on a computer
- Verify that this tonal value is exactly or very very nearly Pure White
- Returning to Zone 5/0EV... lower the EV by 1EV
- Take a photo
- Measure and note as Zone 4 the tonal value on a computer
- Lower the EV by 1EV
- Take a photo
- Measure and note as Zone 3 the tonal value on a computer
- Lower the EV by 1EV
- Take a photo
- Measure and note as Zone 3 the tonal value on a computer
- Lower the EV by 1EV
- Take a photo
- Measure and note as Zone 2 the tonal value on a computer
- Lower the EV by 1EV
- Take a photo
- Measure and note as Zone 1 the tonal value on a computer
- Lower the EV by 1EV
- Take a photo
- Measure and note as Zone 0 the tonal value on a computer - this should record as #00/00(decimal), Pure Black
In practice, older/early mirrorless cameras only provide +/-3EV on the exposure wheel. In these cases I use "M" (Manual) mode, set the aperture and ISO, then vary the shutter speed by 1EV up/down the test range. On more recent cameras where +/-5EV is available on the I set the system to "S" (Shutter) mode, set the ISO, then vary the EV by 1EV using the exposure wheel. Why any company allows +5EV is beyond me, but that's a topic for another time (noting that +5EV is 1EV ABOVE completely and utterly saturated pure white).
Notes On USE: In a practical sense I find Zones 3 through 7 to be the most important. If those are as close to 1EV separated as possible, then I like the output. This is very similar to what I experienced back in the film days.
For the shadow areas I find I prefer Zones 0 through 2 to be rather outside the 1EV separation definition. This matches film curves more closely and since I'm used to that I like a certain combination of Contrast and DRO settings.
For the highlights I like to make them "sparkle" if I can. I find I prefer Zone 8 to be pushing closer to Pure White than not. Having just written that, however, I shot an entire series of in-camera generated images that pleased me using nothing but Contrast == -3. So it's worth testing different combinations of Contrast and DRO to see what works best for oneself.
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