The horizontal white stripes on the Fujifilm GFX100S that I reported on might be related to PDAF banding, but it’s not clear that it is the cause. PDAF banding as I understand it usually causes dark stripes, not light ones (so why is "banding" used instead of "striping" anyway?).
I’ve added 3 more examples with Adobe Camera Raw settings showing the issue, which I can reproduce at will on most images.
Walter B writes:
Appreciate all that you have reported and did not buy into the camera based on the fact that I work in black-and-white exclusively.
But since both J and C have the Fujifilm GFX100S and are testing it extensively, I thought these two would be able to help identify “issues” with the camera and lenses. They have mentioned some to me, but nothing related to banding. However, I have asked both to see if they can show me their practical examples of PDAF banding. Subsequently, J tortured one image to find a small banding area in a blown out overexposed area essentially shooting into the sun, he said he found some. Looking at the files, I could hardly see any.
C has sent me several RAF files which I tried to subject to the settings you used in your blog post Fujifilm GFX100S: Horizontal White Stripes - the Futility of Using GFX100S for Monochrome Landscape Images. (I used C’s image @ 100% to match your settings in LR, Color & B&W) Please review the first two images attached. Unlike your examples, C did not use a polarizer.
Your blog post "Fujifilm GFX100S: Unacceptable Image Quality for Monochrome Images - Horizontal White Stripes”) indicated you used a polarizing filter.
Looking at another blog post example (“PDAF Pimples”) I could not tell if a polarizer was used.
The last two images (again a section of C’s RAF file @ 100% without polarizer) used the settings illustrated by Jeff K in your blog post "How will the Fujifilm GFX100S Fare as to PDAF Banding.” Again I could not see any banding.
But try as I have using C’s RAF files and various LR and PS settings, I could not find any hint of PDAF banding.
I currently use the Pentax 645Z and hope to one day shoot identical images, one with the 645Z and one with the 100S should J or C and I meet up. But until then I am trying to find a reason not to buy into the GFX 100S.
You have made strong arguments but I cannot reproduce the banding and wonder why? What do I need to do to verify the issue? Could it be that the polarizer accentuated the PDAF banding? Do we need to send C to a remote location at 10,000 feet to eliminate atmospheric clutter? I am sure he won’t mind.
What am I doing wrong not finding banding?
P.S. As you suggested, I bought and am using the NEC PA302W and love it! Thanks for that one.
DIGLLOYD: I’m sure it is not related to use of a polarizer, since I’ve proven the issue exists without one. It is also not an 14-bit/16-bit issue. See my conclusions in Don’t even Think about Using the Fujifilm GFX100S for Monochrome Landscape Images — Horizontal White Stripes Make Images Unusable.
Responding to Walter B, I selected 3 images from my last trip semi-randomly, and all showed the horizontal white stripes. Moreover, it doesn’t require use of thefilter; the adjustments alone can show the issue.
I sent them along with processing settings to Walter B:
These are awful!!!!! Not sure why I cannot do the same but it does require caution on my part.
I consider it proven that the Fujifilm GFX100S is a total fail for monochrome landscape imagery. Moreover, "C" has the camera I sold to him, so his findings merely indicate that the conditions did not produce the striping. You cannot prove absence of a problem by not finding it in some cases.
Why or how the horizontal white stripes appear or do not appear—I don’t know. I suspect that it is more of an issue at high altitude perhaps due to blue light, but that is only a hypothesis at this point.
The horizontal white stripes appear 18 pixels apart over the entire frame (14-bit and 16-bit). What on the sensor corresponds to that spacing? PDAP pixels perhaps?