The surprising quality when using the Fotodiox 11 mm extension tube with lenses like Mitakon Speedmaster 65mm ƒ1.4 and the Carl Zeiss T* Sonnar 100/3.5 - making suddenly lovely closeups. I mean the kind of closer images, which are surrounded by a lovely romantic blur, showing a thin zone with pretty good sharpness (with Fujifilm GFX mediumformat cameras).

Yeah. Kind of romantic close-ups, so to speak. Do not take it too seriously; it is just a playful way to get closer, but not meant for serious sharp top notch images. For that you need Macro, tripod and focus bracketing if you want to go serious.

Using lenses on the Fujifilm GFX above 90 mm

I have observed that lenses above 90 or 100 mm with the Fujifilm GFX often need either native Image stabilization in the lens - and/or the use of a tripod - in order to really utilize the large sensor and its high resolution. Handheld it often sucks.

So, even my recently second hand lenses from the Pentax 645 system - the 80-160 mm and the 150-300mm are no fun used free hand. I just don't get that quality or resolution, unless I am using tripod. You need, or I recommend only tripod work with those. The risk of shaking is simply too large (unless the light is very good outside).

I am sure the native Fujifilm 45-100/4 OIS lens works better in many ways free hand, as well the GF 100-200/5.6 OIS. All other adapted lenses - I highly recommend to be used with a tripod. Which in a sort of way ,made my purchase of the Pentax lenses a bit necessary, I realize... Since i rarely go out with a tripod. Unfortunately. (I used to be endlessly better at that earlier).

Talk about "spoiled".

Two things i like very much

I really like with the Mitakon 65/1.4 + 11mm tube

1) that i can get closer than the normal focus down to 70 cm.

2) that the optical quality is holding up just enough (not getting worse) in order to make photos lovely with a certain kind of flair / blur / smooth bokeh). IF you need better detail sharpness, then stop the lens down 1-2 stops. Wide open aperture, at the closest focus distance - fine details look very fuzzy. (Same goes for the Fujifilm GF 55/1.7 lens with 11mm tube) while the depth of sharpness is EXTREME shallow (just a few mm).

Sometimes it helps to increase the distance a notch, and stopping down the aperture a little bit.

The native Mitakon 65mm ƒ 1.4 always felt having a too distant min focus distance (70 cm) - but i could understand that given the softness at wide apertures, that it would only get worse, if the lens had allowed a closer focus distance.