Reader Comment: Fujifilm GFX50S II for Monochrome Conversion and Infrared as Companion Camera to Fujifilm GFX100S?
Related: black and white, chroma noise, Contrast and Phase Detect Autofocus, distortion, focusing, Fujifilm, Fujifilm GFX100S, Fujifilm GFX50S II, Fujifilm medium format, Fujifilm mirrorless, infrared, medium format, noise, optics, Phase One, reader comment
Anon writes:
I am thinking a converted to Monochrome Fujifilm GFX-50S II could be the solution to monochrome with the GF lens set alongside GFX100s for colour. Though the GFX-50S "M" would probably be only a little better than my D850M, it means I could use one set of lens/batteries UI etc.
Also, I tested the PhaseOne IQ4 colour and Achromatic backs last weekend on XT body. Beautiful results but super hard to focus as all manual and really crappy LCD. Tethered is the only solution, but not realistic in the field IMO. Also interesting that Achromatic back was not sharper vs colour back - unlike my Nikon 850M - going to take that up with Phase One, will let you know what I find out.
I filtered the Achromatic with a UV/IR cut that Phase provided. I did tests at f/5.6 and f/8. f/8 is slightly softer, but not dramatic. Clearly (to me now after IR tests) diffraction is dominant wavelength dependent. I got the same result with several test scenes - swapping backs a few times / flat text against a wall so focus was not super hard. Yes the Achromatic was slightly sharper, but more because it didn't have chroma noise from the Bayer processing. Something I never realised until doing these tests was that the Bayer processing can introduce chroma noise - this was sharp black text edges. This was quite clear with my D850M images. The fine text of the target has a lot of chroma noise that disappeared once it was run through Monochrome2DNG. Clearly a side effect of the Bayer processing, not the capture and confirmed by others.
So I did not do a critical focus test with an attached monitor - maybe I should have, but by that point I had already decided that the current shitty LCD was a non-starter for me, even if I had the money. I am also pretty confident that the consistent result over 100+ images back on back off a few times, is correct. But we will see what Phase One says in due course.
In the IR shots with IR pass filter the difference between f/5.6 and f/8 was much more noticeable. I guess the effect of longer wavelength vs tiny sensor sites. That's another plus for the Monochrome GFX-50S II, bigger sites would make it more forgiving on IR DoF.
All interesting stuff and thank you for your continued contribution, I signed up to everything you offer to support my exploration of Camera direction for next 10 years. I think the GFX-50S II nailed it for me, a GFX100s fall back for monochrome, if I find the PDAF too much of an annoyance with the GFX100s.
After 10+ years of Nikon DSLR, I think my mirrorless solution is Fujifilm. I feel most importantly they are making the right decisions. It would not surprise me if their GFX100 replacement is not higher res, but lower noise and faster processing with improvements like XQD card support. Maybe some better lens, not sure if the GF lens are really good enough or not. The XT lens performance was just stunning.
Who needs more than 100 megapixels? We just want better pixels @ 100Mpixels.
DIGLLOYD: 100 very high quality megapixels (e.g., true color pixels) are as good or better than 150 so-so megapixels, depending on the differences. But lens quality can easily span the same range, which is why I like to bitch and moan about high-priced high distortion lenses and the need for distortion correction.
Diffraction affects red (longer) wavelengths much more than blue (shorter wavelengths), and infrared even more than red.
Presumably the Fujifilm GFX50S II can be converted to monochrome, like Fujifilm GFX50S. But I would greatly prefer a true pro camera for landscape of 100 megapixels, that is, one without the Fujifilm GFX100S/100 horizontal white stripes yuck and that means no PDAF pixels to crap-up the image quality—I’d pay extra for a non-PDAF sensor. I don’t give a damn about focusing speed when shooting landscape; I want top image quality and in particular I want clean monochrome conversions, which the GFX100S/GFX100 cannot do.
Yes, the PhaseOne IQ4 back gets the prize for the world’s shittiest LCD on a camera today, feels like 2008 technology. On the most expensive camera too!
The Fujifilm GF lenses as a group are very good, but there is absolutely room for higher performance than some of them provide.
Weldon Brewster writes:
Hope all is well. I disagree with one of your readers (Anon) comments about the IQ4 150 and IQ4 150 Achromatic. I own both the XT and XF cameras along with both the IQ4 150 and IQ4 150 Achromatic digital backs.
Yes, the LCD screen could be better. However, the Phase One XT is one of the easiest cameras to focus I’ve ever used. You set the focus mask to provide your exact depth of field and pick your point of focus. It takes a few seconds at most.
I come from a 4x5 and 8x10 film background so all manual seems very intuitive to me. Focus on the Achromatic is just as easy but the focus shifts as you change IR filters. The UV/IR 486 filter will focus on one plane but a 690nm or 830nm filter will focus on a different plane. It’s really easy to make the focus adjustment though.
I’m also not sure you use a camera system as complex as Phase One for a weekend and decide all of it’s strengths/weaknesses. Here’s a link to some Phase One XT images: https://www.weldonbrewster.com/-/galleries/phase-one-xt It’s a long term project I’ve been working on for the last two years.
DIGLLOYD: I have not used the XT system, so I cannot comment. But I do know that it’s incredibly difficult to focus a camera exactly when it comes to 3.76 micron pixels even with a top-notch EVF, and that a slight miss is plain to see in unwanted deviation in places in the frame from nearly unavoidable field curvature, even at f/8. This is true on the Fujifilm GFX100S/100 and it was true on the PhaseOne XF.
