Move to GFX or stick with Sony?

[Andy81]

I've been a Sony user ever since I started in photography in 2007, and currently have the following:

Sony A9

Sony 16-35 f4 PZ

Sony 24-105 f4

Sony 85 f1.4 GM

Sony 70-200 f2.8 GMii

Sony 200-600 G

Most of what I shoot is portraiture/studio work (including the odd studio dance shoot), and some landscape/cityscape work thrown in, plus family photos.

I've noticed that some of my high contrast studio images are suffering a bit in post processing due to the reduced dynamic range of the A9 sensor, particularly specular highlights etc, and the files don't give me much latitude for editing.

Given this, I'm thinking of changing the camera, either with an A7r4, A7r5, or moving to Fuji GFX and reducing the length of the lend line up (either way, the 200-600 probably goes, as I use is 2-3 times a year).

If I moved to the GFX system, I'd probably limit myself to a body (not sure which one yet), the 35-70 'kit' lens and the 110 f2 (broadly using the funds from selling all the Sony gear to put together a small GFX kit)

Am I crazy for even considering GFX rather than staying with Sony?

Any advice on which GFX body would also be welcome, as I don't want to end up with selling my Sony gear and having to stump up an additional £2-3k to do this (my wife certainly wouldn't approve)!

Thanks

Andy

 

[Nokiron]

I've been a Sony user ever since I started in photography in 2007, and currently have the following:

Sony A9

Sony 16-35 f4 PZ

Sony 24-105 f4

Sony 85 f1.4 GM

Sony 70-200 f2.8 GMii

Sony 200-600 G

Most of what I shoot is portraiture/studio work (including the odd studio dance shoot), and some landscape/cityscape work thrown in, plus family photos.

I've noticed that some of my high contrast studio images are suffering a bit in post processing due to the reduced dynamic range of the A9 sensor, particularly specular highlights etc, and the files don't give me much latitude for editing.

Given this, I'm thinking of changing the camera, either with an A7r4, A7r5, or moving to Fuji GFX and reducing the length of the lend line up (either way, the 200-600 probably goes, as I use is 2-3 times a year).

If I moved to the GFX system, I'd probably limit myself to a body (not sure which one yet), the 35-70 'kit' lens and the 110 f2 (broadly using the funds from selling all the Sony gear to put together a small GFX kit)

Am I crazy for even considering GFX rather than staying with Sony?

Any advice on which GFX body would also be welcome, as I don't want to end up with selling my Sony gear and having to stump up an additional £2-3k to do this (my wife certainly wouldn't approve)!

Thanks

Andy

My main gripe with GFX is that the system is incredibly slow if you compare it to comparable Sony cameras, especially continuous auto-focus. If you are photographing family with moving kids or people none of the GFX bodies I've tried will be able to keep up. So I would be a bit worried about the dance shoots depending on how that is. In that use case I've tried both GFX 100s and 100s II without much success. The images look lovely when it focuses, but that is in the very best case 1 in 5 images, if even that.

It's a whole different world with the A7RV I also use, where I've never really missed a shot.

But going from the A9 is also a big difference, you are losing quite a lot in burst rate.

 

[Rodenmg]

This is a perfect time to rent before you buy. First the A7 and see if that small difference in DR is actually visible and then a GFX100 II with the GF110 f2 to see if you can work with the difference in speed of overall use and AF limits.

--
... Mike, formerly known as Rod.
... https://www.flickr.com/photos/198581502@N02/

 

[cathal gantly]

I'm considering adding a GFX body to use alongside my micro four thirds system, using adapted Mamiya lenses I have for my 645 system. In my use case scenario, the GFX would be used for "slower" photography, and where ultimate quality is required.

So far I've held off. The things stopping me are would I give it sufficient use to merit the expenditure, and would a high resolution FF system (mirrorless or dSLR) be just as good?

I've been reading Kirk Tuck excellent blogs (Visual Science Lab ) for about 15 years, and find I'm broadly aligned with his views and tastes. He's no stranger to medium format, and a few years ago added a GFX system to his inventory. He's recently sold all that off, and instead is now just using Leica, especially SL series, cameras. Of particular interest to me was his statements that the high resolution SL models were just as good. Read his excellent blog for more details and real world experiences.

There is a very different use case for medium format, which won't work for everyone. Given your existing investment in lenses and (presumably) accessories, perhaps a high resolution SONY body is a more cost effective and smoother transition for your own use case?

Sorry I can't personally offer any real world experience.

 

[widi5006]

If your main subjects are moving more than at a snail's pace then the hit rate with the Sony will be considerably higher. On the other hand the files from the GFX will give you a LOT more lattitude when editing....the dynamic range I can recover out of the GFX is ridiculously good. For reference I own the Sony A1 and the GFX100s....if ultimate image quality and dynamic range is a priority then the GFX wins for sure....on the other hand if I need absolute reliable AF then I will grab the Sony, no question.....so pick your poison I guess, I am lucky that I have both. As a side note I used to own the A7RV as well and I would say the AF is a bit better than the A1 (which is already excellent though, and the high FPS are awesome to have for action shots)

 

[Trk]

Sony a7R V, even as hobbyist I have like 95% correctly focused images with rich dynamic range. You as pro will have 124% success rate.

 

[Jeff2013]

I shoot both systems: A1 (A1 II on pre-order), A7R5 and GFX 100S II.

I acquired the A9 that you shoot when it was first released. While, at the time, no-blackout 20 fps was amazing, I never liked the dynamic range penalty of this camera. Recovering shadows often resulted in too much color noise, for my liking. Also, for me, 24mp was not enough for nature shooting where cropping is the norm.

I recommend that you acquire a used A1. Like new condition A1's are available over on Fred Miranda for $3600 to $3800 USD (I didn't look to see what country you are in, so your source may be different). You can take advantage of the current glut of used A1's as folks dump them for the new A1 II. Another option would be an A7R5 at even less cost.

I fairly recently acquired the GFX 100S II - mostly for portrait shooting. I really like the aspect ratio of medium format for that type of shooting. I also really like the ergonomics and menu system of the Fuji. Overall, I love the camera.

When I acquired the camera, I tested it with the GF 55mm f1.7 against my A7R5 with the GM 50mm f1.2. Almost surprisingly, when the GFX 102mp files were down-converted to the 61mp of the Sony, for comparison, and viewed on a 27" 5K monitor at 100/200%, the two were virtually equal in sharpness and detail; plus, the bokeh was the nearly identical. Of course, viewing the 102mp files at 100/200% showed more detail, but one would need to render very large images to see it. In the end, I much prefer the aspect ratio of the Fuji for much of my shooting. Cropability is also a plus. There are also small advantages of the Fuji over FF, such as slightly lower noise and dynamic range at ISO 80, color gradation refinement, skin tones, etc.

If you are drawn to Fuji GFX, I would do it at a time when you can afford to add to your Sony kit, but not replace it. I would never completely give-up my Sony FF (or Nikon, Canon) system for medium format, as great as it is.

--
Jeff
Florida, USA
http://www.jefftitteringtonphoto.com

 

[Greg7579]

OP - I will be happy to answer you privately. PM your email I can't answer it on PM but will on email.

But first, please search this forum for the 20 previous OPs who ask this same question at least 3 times a month for the past 5 years here.

It is probably the most important question asked on this forum, but it always results in the exact same answers and arguments by the same people in offering their advice. I get in trouble with my friends here almost every time, so I will not be answering this question here on this thread.

I will just say this, and then I will not respond to any other response on this string.

If you have the money and it makes sense for you financially, if you make the commitment and go GFX you will not be sorry.

I have answered these threads for years and I can tell you that many people after asking this here have ended up buying the GFX kit (not because of me) and only one regretted it that I know of, he or she had other extenuating circumstances in play.

But remember, this is all just my opinion - nothing more. Plus, I hate shooting portraits with a passion that nauseates me, so don't listen to me if you are a portrait guy. In my experience, GFX MF, Leica FF, Canon FF and Nikon FF all fail miserably at portraits because I have shot them all and my portraits are always horrible.

Lat week I was at Thanksgiving with Family and flew from Texas up to NC to stay with my daughter at her huge house in Chapel Hill. It was full of all my kids and 7 grandkids. I took my GFX 100II and 45-100. No lights (I have every light known to mankind acquired in my recent failed portrait photography phase of life).

I ordered my grandkids to stand in a group and face me. They all resisted and two cried. I shouted at them to smile but not show their raggedy and missing teeth. I said close your mouths and smile at grandpa! One asked a question, and I said, shut up and pose! Then I started screaming at Sammy who was crying and said, "Sammy, there is no crying in photography! Go to your room!"

I snapped these and my two daughters and son had way better shots with their phones.

So, my conclusion is you should sell the Sony gear, don't buy GFX and just shoot portraits with a phone.

Here are my most recent failed GFX portraits. I blame the mediocre work on GFX (and on my snotty grandkids and their failure to follow my instructions).



View attachment cfb9548ef9144c638b9f0b4c14977434.jpg
My daughter in her back yard with her three sons. She is a physician at UNC and he is a physician at Duke. I kept yelling at Tucker not to smile and to close his mouth. I love the trees growing out of their heads. That is what I was going for.



View attachment 60f60b3c970e423d972dcc96f59cb2b1.jpg
I was screaming at Tucker to look at Grandpa. But he kept looking down! I put him in Timeout for an hour for that.



View attachment 170196a43d1f48fd9f7f3e63dec31769.jpg
My 7 grandkids. There are 15 phone shots from several different phones better than this GFX shot. Proof that you don't need anything but a phone. No need for Sony FF or GFX MF.



View attachment 7e6e98e264a84ce2bc62bbcb235868b9.jpg
I failed on this one because one of the grandkids is missing. I yelled at him to stop jumping around and he jumped off the swing and ran away crying. I put him in Timeout and didn't let him have any cake at dinner. They need discipline and they all are terrible at posing, despite my expert instruction.



View attachment d00e9eb7b331437b87187f5254f22129.jpg
My son and his three kids. This shot looks dull and flat, but it was raining. Plus, everyone was freezing because I made them take off their coats. GFX failed at this portrait attempt. My son is terrible at posing. That hand is all wrong!



View attachment cfc3fc419a9d4230911e4c63d12593e6.jpg
Look! Sammy was crying! I yelled at him to stop crying and put him in Timeout.



View attachment 952bb070790b428e9325603f11c05dcc.jpg
Terrible group portrait. They would not hold still and GFX can't focus track.

--
Greg Johnson, San Antonio, Texas

Greg Johnson’s albums | Flickr

www.flickr.com

 

[Andy81]

Thanks all for your comments. I'm not too fussed about losing the A9 burst rates, as I rarely do fast action stuff, and if I'm honest, an A9 for family photography is very much overkill - I could pick up a compact for that if needed.

My reservation on the GFX is around the autofocus - the dance shoots I mentioned are always in studio - example image below. Most of my other serious photography is either studio portraiture/fashion or similar on location, nothing involving fast action.







I can't justify running 2 systems, hence the dilemma - the Fuji system would force me to reduce the lens line up which isn't necessarily a bad thing!

I'm going to have a look on my Lightroom catalogue to see which focal lengths I've been using most, as this will help me see if I'm likely to miss having the range from 16mm to 600mm on FF, and I'm also planning to use the Fuji loan system to try out a GFX100Sii, though its likely that if I did invest, it would be either a GFX100, GFX 100S or GFX50Sii.

 

[Doppler9000]

You will get a significant jump in DR with a newer Sony, along with better autofocus compared to the GFX.

 

[JimKasson]

You will get a significant jump in DR with a newer Sony, along with better autofocus compared to the GFX.

At low ISO, the a7RV will get you most of the way to the GFX 100 II PDR.













--
https://blog.kasson.com

 

[Greg7579]

Thanks for the PM. I'll email you my thoughts on GFX in general. You are high end professional fashion and portrait guy and you have the Sony glass and those great cameras so why jump?

(I know why you are tempted. But I won't delve on that here.

There are world class Haute Couture, fashion and portrait pros who shoot GFX for a reason and you could talk to them. I'll email you some names. Ben K and Manzur would talk to you for sure.

But unless you want GFX for other types of shooting and for fun, IQ, high res and other niceties and you are getting good pro results with your FF Sony gear - I'm not so sure you should go there unless you have lots of money and want to have some fun.

You'll know soon. Once they come here and ask, they usually have already made up their minds.

You are a pro. You already know.

But sometimes we need a bit of soothing hand holding and I am not in a position right now to do that for you even though I want to give you that assurance.

Look at some of my previous advice concerning this. It is easy to find.

 

[bobby350z]

Thanks all for your comments. I'm not too fussed about losing the A9 burst rates, as I rarely do fast action stuff, and if I'm honest, an A9 for family photography is very much overkill - I could pick up a compact for that if needed.

My reservation on the GFX is around the autofocus - the dance shoots I mentioned are always in studio - example image below. Most of my other serious photography is either studio portraiture/fashion or similar on location, nothing involving fast action.



I can't justify running 2 systems, hence the dilemma - the Fuji system would force me to reduce the lens line up which isn't necessarily a bad thing!

I'm going to have a look on my Lightroom catalogue to see which focal lengths I've been using most, as this will help me see if I'm likely to miss having the range from 16mm to 600mm on FF, and I'm also planning to use the Fuji loan system to try out a GFX100Sii, though its likely that if I did invest, it would be either a GFX100, GFX 100S or GFX50Sii.

Above shot you aren't using fps in AF-C. So doable with GFX. I would look at GFX100 II over the other models. Lens wise for studio look at 45-100mmf 4. I have 110mm f2 but the zoom is more flexible in the studio.

 

[dbateman]

I'm considering adding a GFX body to use alongside my micro four thirds system, using adapted Mamiya lenses I have for my 645 system. In my use case scenario, the GFX would be used for "slower" photography, and where ultimate quality is required.

So far I've held off. The things stopping me are would I give it sufficient use to merit the expenditure, and would a high resolution FF system (mirrorless or dSLR) be just as good?

I've been reading Kirk Tuck excellent blogs (Visual Science Lab ) for about 15 years, and find I'm broadly aligned with his views and tastes. He's no stranger to medium format, and a few years ago added a GFX system to his inventory. He's recently sold all that off, and instead is now just using Leica, especially SL series, cameras. Of particular interest to me was his statements that the high resolution SL models were just as good. Read his excellent blog for more details and real world experiences.

There is a very different use case for medium format, which won't work for everyone. Given your existing investment in lenses and (presumably) accessories, perhaps a high resolution SONY body is a more cost effective and smoother transition for your own use case?

Sorry I can't personally offer any real world experience.

For you, yes you should look at gfx options. I tag team my m43rds cameras with gfx and now mostly use the gfx cameras. I can crop the gfx100, to get basically the same image field of view as the Em1mk1 and Em5mk2 cameras. I will use the m43rds when I want a faster lens for faster shutter speeds. Or a lighter camera.

If you like the 43rds sensor, using m43rds and gfx make sense to me.

 

[JimKasson]

Sony a7R V, even as hobbyist I have like 95% correctly focused images with rich dynamic range. You as pro will have 124% success rate.

Does that mean you can have great pictures even if you don't trip the shutter?

 

[Rand 47]

Sony a7R V, even as hobbyist I have like 95% correctly focused images with rich dynamic range. You as pro will have 124% success rate.

Does that mean you can have great pictures even if you don't trip the shutter?

Yes! It’s the latest craze called NENFTs. (Non existent non fungible tokens)

Rand

 

[John Crowe]

It makes absolute sense to try the A7RIV or V first. If budget is a concern then try renting one first, or buy used. If you feel it was not an upgrade, then you can sell it with not much loss.

I recommend adding medium format to your current system, rather than switching completely.

 

[GeoffHarris]

I am a Sony user (with an A9, like you), daydreaming of dipping my toes in the GFX system one day when everything lines up right and I can afford to.

I think autofocus is going to be a big issue. You've got to be careful to manage your expectations of what is feasible.

You'll be very used to the effortless, bulletproof reliability of your A9, like I am. It just gets the shot. Nails it. You can trust it. I honestly think it's a huge quality of life boost even if you aren't shooting any kind of sports or anything particularly dynamic - it just completely nails shots, time and again, which is even significant when shooting ordinary non-action portraits for how it removes a whole layer of concentration and distraction from the moment.

The newest generation GFX bodies have the system's best-yet autofocus which, depending on your use case, is sometimes good enough. But it's never close to what the A9 achieved all those years ago. This is not yet thoughtless / "shoot at the speed of thought" autofocus. Again, I'm not talking about action shooting. I'm talking about "completely, forget-it's-even-a-thing-grade reliable, even for relatively unchallenging shooting".

Even shooting that we'd consider unchallenging can be more testing than we consider. You spoke of studio shooting, and you've posted an example. Strobe shooting? How's the lighting in that studio, before the shutter is fired? The A9 is an absolute legend at just leaping out and grabbing focus, even if your modelling lights are mediocre and your studio is gloomy. It's so good at it that you forget how good it is.

One of the things the GFX 100 II and 100S II were reputed to be an improvement on, was autofocus in lower light. Read: Studio. Your studio. The best-case-scenario autofocus performance... shooting outdoors in plentiful daylight, for example... is very much not your indoor studio environment.

The "II" versions of the GFX 100 lineup are very expensive.

The mark one versions are in some cases very affordable but I really think they'll fall down below the "practical, usable, not a frustrating step down" threshold, particularly for your studio shooting. When the mark II bodies came out, launch-day product demonstrations were showing off how well it focuses in dark studio environments now... guess why? Because the mark 1 needed to improve on that.

No dispute whatsoever on the image quality. The upgrade there from an A9 to a GFX 100 body is immense.

If I do eventually find myself fortunate enough to buy a GFX, it'll probably be a GFX100 (mark one) for budget reasons... and I am being deliberately pessimistic and cautious about my expectations so as not to be disappointed. I had already told myself "this is just going to be for outdoor portraits in certain specific circumstances/roles" - that's all I would want it for, and dare to hope for it to cope with - rather than daring to hope it can be an all-portrait-roles camera.

Happy for anyone to tear this speculation to shreds. I don't own a GFX! I've done a lot of reading and watching to try to look before I leap, given the cost of trying them out... but none of it is a substitute for real experience. I'm just trying to not let you give yourself an expensive surprise, when the full implications... of the extent of the step-down from the autofocus of the A9 that you've gotten used to... make themselves apparent. Because these are the considerations that had been running through my own head, and you reminded me of them again when I saw your thread.

I think you'd need to get a 2nd-gen 100 body to get autofocus that doesn't bother you (and even then, it's not the same experience and liberatingly effortless reliability, even for unremarkable studio stuff)... and the price implications of that will be severe. But the step down in focus performance to gen 1 for budget reasons would be severe, as well. Difficult tradeoff.

Again, no dispute on the image quality issue, and I'm happy for anyone to rip all this to shreds. But often your quality-of-life with the A9 has nothing to do with its maximum burst, or blackout avoidance, or whatever - it's just how completely that surefooted autofocus frees you up when taking individual shots, in whatever circumstances, with not-perfect light to focus with. And I think that's going to maybe bite you when you switch to GFX, so you'll maybe want to think about what you're willing to settle for.

 

[Jeff2013]

I am a Sony user (with an A9, like you), daydreaming of dipping my toes in the GFX system one day when everything lines up right and I can afford to.

I think autofocus is going to be a big issue. You've got to be careful to manage your expectations of what is feasible.

You'll be very used to the effortless, bulletproof reliability of your A9, like I am. It just gets the shot. Nails it. You can trust it. I honestly think it's a huge quality of life boost even if you aren't shooting any kind of sports or anything particularly dynamic - it just completely nails shots, time and again, which is even significant when shooting ordinary non-action portraits for how it removes a whole layer of concentration and distraction from the moment.

The newest generation GFX bodies have the system's best-yet autofocus which, depending on your use case, is sometimes good enough. But it's never close to what the A9 achieved all those years ago. This is not yet thoughtless / "shoot at the speed of thought" autofocus. Again, I'm not talking about action shooting. I'm talking about "completely, forget-it's-even-a-thing-grade reliable, even for relatively unchallenging shooting".

Even shooting that we'd consider unchallenging can be more testing than we consider. You spoke of studio shooting, and you've posted an example. Strobe shooting? How's the lighting in that studio, before the shutter is fired? The A9 is an absolute legend at just leaping out and grabbing focus, even if your modelling lights are mediocre and your studio is gloomy. It's so good at it that you forget how good it is.

One of the things the GFX 100 II and 100S II were reputed to be an improvement on, was autofocus in lower light. Read: Studio. Your studio. The best-case-scenario autofocus performance... shooting outdoors in plentiful daylight, for example... is very much not your indoor studio environment.

The "II" versions of the GFX 100 lineup are very expensive.

The mark one versions are in some cases very affordable but I really think they'll fall down below the "practical, usable, not a frustrating step down" threshold, particularly for your studio shooting. When the mark II bodies came out, launch-day product demonstrations were showing off how well it focuses in dark studio environments now... guess why? Because the mark 1 needed to improve on that.

No dispute whatsoever on the image quality. The upgrade there from an A9 to a GFX 100 body is immense.

If I do eventually find myself fortunate enough to buy a GFX, it'll probably be a GFX100 (mark one) for budget reasons... and I am being deliberately pessimistic and cautious about my expectations so as not to be disappointed. I had already told myself "this is just going to be for outdoor portraits in certain specific circumstances/roles" - that's all I would want it for, and dare to hope for it to cope with - rather than daring to hope it can be an all-portrait-roles camera.

Happy for anyone to tear this speculation to shreds. I don't own a GFX! I've done a lot of reading and watching to try to look before I leap, given the cost of trying them out... but none of it is a substitute for real experience. I'm just trying to not let you give yourself an expensive surprise, when the full implications... of the extent of the step-down from the autofocus of the A9 that you've gotten used to... make themselves apparent. Because these are the considerations that had been running through my own head, and you reminded me of them again when I saw your thread.

I think you'd need to get a 2nd-gen 100 body to get autofocus that doesn't bother you (and even then, it's not the same experience and liberatingly effortless reliability, even for unremarkable studio stuff)... and the price implications of that will be severe. But the step down in focus performance to gen 1 for budget reasons would be severe, as well. Difficult tradeoff.

Again, no dispute on the image quality issue, and I'm happy for anyone to rip all this to shreds. But often your quality-of-life with the A9 has nothing to do with its maximum burst, or blackout avoidance, or whatever - it's just how completely that surefooted autofocus frees you up when taking individual shots, in whatever circumstances, with not-perfect light to focus with. And I think that's going to maybe bite you when you switch to GFX, so you'll maybe want to think about what you're willing to settle for.

I mostly agree with you, but as a new user of GFX, I have been amazed with how good my relatively new GFX 100S II has been in terms of focusing in low-light.

The shot below, was taken in near darkness. Without turning-on the modeling light on my strobe, I could barely see the face of my subject, in the darkness, but Eye Focus instantly grabbed his eye and the focus was perfect... as was most all of my shots that evening.

When I shoot in difficult conditions with my GFX, I normally keep my Sony equipment in the car, just in case. Surprisingly, I have never had to retrieve it.

Overall, the Eye Focus for people, animals and birds seems to function just about as well as my A1/A7R5 and the Z8 & R5 that I have tested. Honestly, I never expected that - particularly, for distant, small birds with my GF 500mm.

The Achilles Heal of the GFX camera is shooting moving subjects - particularly, fore & aft motion.



--
Jeff
Florida, USA
http://www.jefftitteringtonphoto.com

 

[Erik Kaffehr]

I've been a Sony user ever since I started in photography in 2007, and currently have the following:

Sony A9

Sony 16-35 f4 PZ

Sony 24-105 f4

Sony 85 f1.4 GM

Sony 70-200 f2.8 GMii

Sony 200-600 G

Most of what I shoot is portraiture/studio work (including the odd studio dance shoot), and some landscape/cityscape work thrown in, plus family photos.

I've noticed that some of my high contrast studio images are suffering a bit in post processing due to the reduced dynamic range of the A9 sensor, particularly specular highlights etc, and the files don't give me much latitude for editing.

I wouldn't think it matters. A9 is more intended for speed than IQ, so you would see some benefit with GFX or for that part with Sony A7R that is more wired for high IQ than speed. But, if you see a problem, it may be more about work flow than minor differences in image quality.

Given this, I'm thinking of changing the camera, either with an A7r4, A7r5, or moving to Fuji GFX and reducing the length of the lend line up (either way, the 200-600 probably goes, as I use is 2-3 times a year).

If you need the 200-600, you nee it. If you don't need it, ignore it.

If I moved to the GFX system, I'd probably limit myself to a body (not sure which one yet), the 35-70 'kit' lens and the 110 f2 (broadly using the funds from selling all the Sony gear to put together a small GFX kit)

I don't think that makes a lot of sense, except you need 35-70 and GF 110, I would see the GF 110 as a very specic lens with exceptional performance for large aperture shooting. It will suck if you need 80 mm at f/5.6,

Am I crazy for even considering GFX rather than staying with Sony?

May be, or may be not. Analyze your needs.

Any advice on which GFX body would also be welcome, as I don't want to end up with selling my Sony gear and having to stump up an additional £2-3k to do this (my wife certainly wouldn't approve)!

Thanks

Andy

I would keep what I have. But, I think that A9 may be suboptimal for anyhting except sports and birds in flight.

With any system, try to make best of it. Learn to achieve optimal exposure and optimal focusing.

Look at what lenses you need and chose a system that delivers on the lens system.

The A9 that you have is pretty optimal for sports. No MF system is ever coming close to that.

If you shoot landscape on tripod, a GFX 100 system will deliver near perfect image quality, presuming you focus accurately, expose correctly and use optimal apertures,

Best regards

Erik