I bumped into a photo thread which spoke more about the Fotodiox Vertex adapters for various mediumformat lenses. I have always wondered if there is any difference between the Pentax 645-GFX Vertex, and the Pentax 6x7-GFX version.

Apparently. There is none.

Are the same resulting 65x65mm

Which means, that the FotodioX Vertex for Pentax 645, makes 65x65mm images (like the Vertex for Pentax 6x7 lenses does, too)

But with the difference that the Pentax 645 lenses often don't fully cover those 65x65mm !

Pentax 645 FA 35/3.5 lens with Vertex Pentex 645-GFX

Some do, others barely, and some do not

(you have to crop the image a bit). I have seen real full photos made with the Pentax 645 FA 35mm ƒ3.5 lens showing dark corners with some coloration and of course a little bit of degrading sharpness at the extreme corners !

Which is natural given that the image circle is smaller than the adapters allows to show. While the Pentax 67 lenses cover entirely the 6x7-GFX frame (which I call 7x7 cm).

Say again - what is the Vertex adapter ?

You know, VERTEX is the adapter in which you take 4 images with the Fujifilm GFX 50 camera (4x50 MP each) on a tripod - while for each [locked] exposure, you turn the Fujifilm GFX camera by 90°.

Later - you stitch all four images into larger image, equivalent to a 6.5 x 6.5 ("7x7" cm sensor) at around 125-150 MP (give or take). I think it almost triples in MP. It is as if you're using a very large 65x65mm digital image sensor. Or using classic 120-film for the 6x7 film format.

It shows much more the original character of the lens, as it shows also the borders and its characteristics.

the four photos of a morning tired Sal as test object -
where the camera is rotated for every photo by 90° - and then stitched together.

The image circle of the 6x7 lenses are covered by this photo being equivalent of a 65x65mm digital sensor, or 7x7
which is slightly larger than what you would get with a 6x7 camera on 120-film

No sense with a Fujifilm GFX 100+ model

However, i agree to the more professional photographers who wrote, that when switching to Fujifilm GFX 100 - you have so much resolution, and so fantastic Fujifilm GF lenses - that there isn't any advantage anymore to use the Vertex or any other stitching method.

Images with a 100 MP sensor and then stitched to even bigger ones - become so extreme large and heavy... you may ask yourself the question, if that is even reasonable to deal with. There is no advantage in it as a normal creative photographer.

And to use the Vertex adapter with vintage lenses, and say 300 MP outputs - but the resolution ends up still being better with "just" 100 MP images taken with sharp Fujifilm GF lenses.

You can of course, and will likely do it - using vintage lenses for their character - not for getting super sharp, super defined images. That's not what vintage lenses are about. They are about character, feeling, emotion - and at times also weirdness.

I do however like the VERTEX method with the "smaller" Fujifilm GFX 50s II model. I think the 51 MP sensor is simply perfect for that. Also; it copes very well with longtime exposures without a lot of hot pixels or micro-lens gaps / stripes which seem to appear in the more modern 100 MP sensors from time to time, due to the implementation of PDAF, I suppose. Albeit newer firmware has addressed some of the issues over time, i read.

But is it all fixed now ? I don't know.

Fujifilm GFX 50s II model

Yes, I find the Fujifilm GFX 50s II simply to be the perfect middle among all the GFX cameras up to this date. The GFX 50s II is now also highly affordable - got a highly versatile sensor without going over board. (The computer also has a saying in the matter). The sensor doesn't streak. Has image stabilization, which does help a bit. And the sensor has great latitude, which means the RAW files are highly malleable.

The only thing i sometimes miss, is better / snappier AF. I can sometimes feel that the GFX 50 versions, can overshoot the focus point , and therefore you end up with slightly mis-focused images. It happens sometimes...

But I am not sure if the GFX 100 versions are that much better. I can't judge that really, because I never held or used one. I am sure that the PDAF gives a bit faster AF, more easily snapping into focus (?). But it ain't 100% there either, from what I've been reading and having read, tons of entries in various forums about the GFX platform, lenses and everything around it.

Pesky Fuji GFX Menu's / settings

Oh. I strongly dislike the Fujifilm camera's menus/settings. They are the most obnoxious I've ever encountered in a camera model. They once said, that Olympus had a funky menus. Sony (such as Sony A7s) had horrible ones, too.

But Fujifilm is... just too weird, in far too many ways. I keep searching for something particularly.... every time... And I still do after 1.5 years, feeling lost. Some things stick over time. But a lot does not, and you have to search and search.

It just isn't intuitive. At all.

Savings on Vertex adapter !

So, instead of buying a Pentax 6x7-GFX Vertex adapter - you could buy the Pentax 645 - GFX Vertex adapter instead. Then you can add a genuine Pentax 645-to 67 adapter for 100€. That way you can use both Pentax 645 and Pentax 6x7 lenses with the Vertex method ! The Pentax 67-GFX Vertex adapter in the EU you can get here. x

That way, you don't need to buy TWO expensive Vertex adapters (390€ in Germany at lumiere-shop.de)

Luckily on these Fotodiox adapters, the adapter tripod foot, is MUCH MORE STUDY - compared to the absolutely ridiculous foot held with two tiny, soft screws (which WILL bend immediately) in the Mamiya RZ/RB67-GFX adapter.

What did I do ?

Well, i bought the Pentax 6x7 to GFX Vertex adapter ... Since i focused on those bigger lenses for the Vertex method. Partially because i have tons of Pentax 67 lenses, and because they have a larger image circle. I never intended to use the smaller Pentax 645 lenses. Until now, I mean. But those i use directly on the Fujifilm GFX camera, with a simple straight adapter.

To be honest, I will not buy the Pentax 645 Vertex version.

Given that the 645 lenses will show dark corners, show color changes in the extreme corners and fuzzy sharpness at the borders due to the too small image circle vs Vertex adapters output of 65x65mm. I think 645 lenses have a limit of around 55x55mm or maybe 58x58mm which i assume is the circle of DEFINITION, while the image circle (of illumination) is a bit larger - but vary with the lens model.

I always thought, that Fotodiox made the Vertex version for Pentax 645 slightly smaller (in order to adjust to those lenses with smaller image circle).

Apparently that is not the case.

Options. Options. Options.

Maybe one day, I do add the Pentax 645-GFX Vertex adapter, because I use flexible zoom lenses. Which could be fun. But it ain't a goal, really. More like an additional option available if/when i like. Anyway - I think the Vertex adapters are amazing. Because of the simplicity, you get true mediumformat a lá 65x65mm or what i call 7x7 format. Like in the old days of mediumformat photography with 645, 6x6 and 6x7 cameras.

Today, at this stage, with the many adapters i have been buying since i bought the Fujifilm GFX camera - i can now adapt a whopping 33 lenses in total (from which 3 lenses are genuine Fujifilm GF lenses). The rest is "vintage". Leica M not included, because they are not really useful.

It's all the lenses that have good performance, make sense, and are not too degraded on the GFX. Or which can be used at portrait distance; such as Canon FD 85/1.2 L and the Canon EF 135/2 L lens, which are excellent portrait lenses. Supposedly it also works with the Canon EF 85/1.2 L II lens - which I don't have. I have the older, mechanical FDn version from 1988.

Not that many made for handheld photography

Naturally, not all 33 lenses are made for hand held use. I wouldn't really walk around with the Mamiya RZ67 lenses for example. And most Pentax 6x7 neither, even if some of the smaller ones may work. I enjoy those with a tripod. Also the recently acquired Pentax 645 FA lenses, I think i prefer on a tripod, due to their short focus throw - making it too difficult to be shot from the hip. It is too easy to overshoot the focus point i have noticed. It is much better, when they are used with a tripod, instead.

Fujifilm GF lenses on the other hand, are well made for hand held photography. I never had a problem with that. Albeit i don't really have longer GF lenses, either. It's the GF 23mm ultra wide angle, the beloved 30mm wide angle (my absolute favorite), and the light and rather compact GF 35-70mm zoom.

Then there is the heavy Mitakon 65/1.4 lens, which too, works handheld - but is of tricky nature if you want to nail the exact focus point at aperture ƒ1.4 - which is very shallow and fuzzy. Stopped down to ƒ5.6 or ƒ8 , it is an excellent lens. Actually, it sharpens already up at ƒ2.2 and onwards, just getting better.

That's it.

Lens Geek

Boy, what a lens geek i have become in this life. I sometimes wonder why ?! I sometimes wish I would understand more about lens design. I find the various designs fascinating. Especially back in time, how they evolved in the past 150 years - i find intriguing. I love looking at the cut-through illustrations, and descriptions what those lens elements do, and what are differences becomes in the final images. How it all came about, what various glass types do, etc.

It is just mind boggling.

Something that grew on me over time. I think it started with Leica M lenses - when I bought a couple of special Leica books in the early 90s after i had bought the Leica M6 in 1989... - and started to realize what various lens designs did, and how those where refined over time. Looking at the different optical designs. Yet - I can't say I know much, because I don't. Just bits and pieces.

Yet - it is so fascinating !