(Part 2)

Pentax 6x7 lenses

do NOT in any way approach the optical quality of the native, digital Fujinon GF lenses. Hard stop ! Also, the wide angle lenses appear to be a bit on the weaker side, especially at the borders i notice a lot of mushy details worth the name details (of course it depends if the details are in the zone of sharpness, or outside).

The wide angle lenses like 45mm, 55mm and 75mm do exhibit a slight different color at the borders - something I had not realizing in my many indoor images with the Vertex 7x7 method.

Daylight, light sky - revealed to me, that there are trances of different color towards the borders. Well, keep in mind that the Fujifilm GFX exhibits very thick sensor glass. This results into blur with lenses that are not optimized (e.g. all vintage lenses, or lenses from other brands). And due to the incoming oblique angle of the light at the corners - especially with wide angle lenses - you get some weird optical errors (color introductions, degraded sharpness).

I used the oldest version of the Pentax 6x7 Takumar 55mm ƒ3.5 lens - which is known to be not on top in terms of sharpness. But it has a unique cinematic fingerprint style in images when used with film. I absolutely love that lens with film.

However when using it on a digital camera (with emulated 7x7 cm sensor area), you really can tell that the lens' optical performance isn't on top at all. In the center it is fine - but the borders are not.

Now, since I am getting 150 MP images - you will not see all the aforementioned optical errors - simply because the final image is much smaller.