 Like I said I would, ordering a Tamron SP 90mm macro lens (second hand). It has a Canon EF mount - and got it for an affordable price (compared to eBay).
At a Stockholm Pawnbroker shop it cost in total 360 €, looking practically unused to my eye.
Now, why this Macro lens ?
I explained earlier, that my Sigma ART 70mm Macro lens, has one disadvantage: The inner barrel of the lens moves outwards (extends) when i set the focus.
Scanning larger negatives
Since I am using a Macro lens in order to 'scan' larger negatives in the size of 6x4.5, 6x6 and 6x7 format - the (Sigma) macro lens is attached directly to the bulky VALOI Easy120 scanning device. The problem there is, that the inner barrel of the lens moves when you want to set the focus (manually).
And with it - also the big VALOI scanning devices needs to move (!) [or the camera instead]
Which is both iffy, as well seem to strain the AF motor of the lens, of course. Which is not really such a great idea. Albeit it did work - but did so in a somewhat choppy way. Image it like when a lens gets slightly stuck now and then, when you try to gauge in correct focus. You have to rattle it a little bit (or move/lift the camera ever so slightly), so it the focus gets released anew.
Often I lift the GFX camera slightly in order to be able to focus, due to the weight of the VALOI device "hanging" onto the inner barrel of the lens.
It just feels... well, a bit iffy.
Inner focus (IF)
The Tamron SP 90mm Macro lens works differently: it exhibits so called INNER FOCUS (IF) mechanism. Nothing on the outside is moving when focusing - which means, the VALOI Easy120 can be connected to the lens without anything changes - while I can focus smoothly (manually) onto my negatives (objects).
In other words; Problem solved. Well at this stage... in theory !
Sometimes I tend can get excited about photo tools or solutions, i have read about (when consulting many different sources - which i often do, when i write about photography). But once I personally decide to buy a tool and write about it BEFORE i actually have tested it - I tend to be a bit too optimistic. Like a guy on a planned honeymoon. Only to realize later (that sometimes) there is another issue; showing up a dark cloud lingering at the horizon.
So, therefore i say "at this stage - in theory - it should likely work"
Should work with Fujifilm GFX
The Tamron SP not only works natively with Canon EOS EF mount cameras - but does of course on mirrorless Canon EOS R cameras as well (with a simple EF-RF adapter). But the best part for me is - if it holds true - that the Tamron covers the larger Fujifilm GFX image sensor, as well !
According to Chang - this lens covers the 4:3 aspect ratio beautifully , while the contrast it said to be excellent at ƒ5.6 aperture, all the way down into the corners. He writes:
"4:3 covered, excellent sharpness and contrast in the margins at f5.6, lens sunshade vignettes"
An obvious candidate
Now you see, why the Tamron SP 90mm ƒ2.8 Macro lens (Canon EF mount) became a primary candidate for me to choosefor the Fujifilm GFX; in order to make sharp scans from 6x7 film negatives.
Now let's just hope, Chang was right about that *rolling my eyes* - and that the corners are not super dark when focusing close. [They are barely visible at close-up, but are somewhat softly visible when focused at infinity]
It should be said, that the Tamron SP lens series (with Canon EF mount), works unusual well on Fujifilm GFX cameras. They seem to exhibit larger than normal images circles, therefore also covering the larger GFX with 44x33mm.
I already have the Tamron SP 45mm ƒ1.8 lens - which covers the GFX sensor excellently ! One of those few that really do work well. Supposedly the same applies to the Tamron SP 35mm ƒ1.8 and the Tamron SP 85mm ƒ1.8 lenses, as well.
Here below
You see once more, the Fujifilm GFX camera, connected to the Sigma ART 70mm ƒ2.8 Macro lens - which is connected to the VALOI 120 scanning device. The inner barrel of the Sigma lens, is the part that moves when you try to focus. That's a lot of weight.... "hanging" onto the lens' inner barrel with the VALOI 120.
That is the very reason I'll bought the Tamron Macro lens, which doesn't move while focusing.
| 
