Now that i have the Fotodiox Pentax 645-EF adapter, which i adapt to the Fringer Pro EF-GFX onto the Fujifilm GFX camera - i can now see what those Pentax 645 lenses are all about.

They are good. Within reason, i mean. Not as 'perfect' like native Fujifilm GF lenses, of course. but pretty good, and fully usable - except perhaps wide angle lenses. But that is mainly because of the thick glass layers in the Fujifilm GFX cameras, bending the light at the corners and borders resulting into smear, blurriness and other funky effects.

However, several Pentax 645 lenses appear to be pretty good to my eye !

I also see things more from a perspective of what can be slightly corrected digitally later in post. Such as sharpening as well reducing or eliminating chromatic aberration - then I do that.

Pentax 645 • A 150 mm ƒ3.5

The biggest surprise was the manual Pentax 645 A 150mm ƒ3.5 lens - which i thought was good already at wide open aperture. That I didn't expect.

Pentax 645 • FA 80-160 mm ƒ4.5 Zoom

The other surprise was that the Pentax FA 80-160mm ƒ4.5 zoom that was better than i had expected. At the shortest focal length at wide open aperture ƒ4.5 it was already sharp. The longer end, needed to be stopped down to ƒ8 in order to match. Or you sharpened it a bit more than on the shorter end. Also; it barely showed chromatic aberrations - also surprising !

When I say "sharpening" i mean, to digitally sharpen the image in Photoshop but without that the noise becomes too pronounced. It must still look normal - not overworked !

Longer Pentax 645 lenses, better to be used with tripod !

I think these lenses are still better off as manual lenses and used with tripod. Also; the FA lenses when using manual focus have a shorter throw, which is difficult when you try to set exact focus manually. I felt that the viewfinder shook too much - and for serious work, i would suggest to use them on a tripod instead. Everything just works better, and is more precise. With a tripod, you get that extra quality - especially with these lenses. I think you can cheat too much when using them handheld, and the result will be displeasing when you get home and look deeper into the details of your photos.

I simply think they are overall better used with a tripod. Well, the same goes for, if you use a native Pentax 645z camera - better use a tripod, if you are in for good image quality.

Pentax 645 • FA 120mm ƒ4 Macro

The Pentax FA 120/4 Macro was pretty sharp at all apertures (from ƒ4 to ƒ16), but had a bit of chromatic aberrations, even when stopped down. Not much, but it noticeable, and more than the 80-160mm zoom had. Which surprised me. But it is a macro lens that can indeed be used at infinity - not just for macro.

A little magenta and green, especially in tree branches against a light sky, was common. At was however easily correctable in Photoshop (Raw plugin).

Even here, it is definitely a lens to be used with a tripod. Macro handheld - forget it. You get often more blurry images than not. Which is pretty common. I remember, when i used 15 years ago Canon camera and Daniels Canon EF 100/2.8 L IS Macro lens - even there i managed to get shaky photos. Totally crappy images i made most of the time (except in very bright light).

Today, i know that Macro means tripod.

It is when you get the real good images (from a technical-optical point of view, not necessarily from an artistic view).

I do not suggest that you always should use a tripod - no no. Do sometimes each of it. With. And without. Some shorter macro lenses (preferable in manual focus mode) - you can indeed use handheld.

In fact, I have a very interesting, Swedish photographer - who made some really astonishing work. I will get back to him again - because I find him highly inspirational, and love his different way of approach. And I like his calm, Nordic attitude, without frills or add ons. And the black & white images he made in dull, gray light... ah, simply so beautiful.

Really gave me quite some perspective, on how to look differently at dull weather.

Scanning mediumformat film

I am sure the Pentax FA 120/4 Macro lens will perform perfectly when scanning 6x7 film negatives. I have not tested this yet (as i have to go to work soon) - but given that the lens has proven to perform uniformly sharp at most apertures... I have no reason to believe otherwise.

So, finally i may have found my "primary scanning lens" for mediumformat film - with a mediumformat lens & mediumformat camera.

Boy, what a journey... back and forth, several times.

Pentax 645 • A 45mm ƒ2.8
(Pentax 645 • A 55mm ƒ2.8)

The 45mm lens has the same funky background blur - sort of unsettled like it has on film. It is a lens i actually like on film, including funky background bokeh. Or at least most of the time. Other times it does look a bit weird / more unsettled than other lenses render, while the 55mm is supposedly to be a bit milder.

It does of course the same thing with a digital sensor.

Central sharpness is very sharp in the middle (of both lenses) even at wide open at aperture ƒ2.8 - but then drops very quickly towards the borders. Also; the 645 A 55mm ƒ 2.8 is told to have similar character with insufficient border sharpness. Albeit it works well at ƒ11

Supposedly, the 45mm focal length is sharpest in the zoom version (FA 45-80mm)

Even when stopped down; borders and corners are not that critically sharp. It gets better at ƒ8 of course - but never totally, fully critically sharp.

On the other hand, the 45mm and 55mm lenses are very good at rendering subjects / objects located closer than infinity !

So, what is the reason for the weaker borders/corners ?

Either because of the thick GFX sensor (3 layer glass) stack (4.24 mm in total) - and here i wonder how thick it is in the Pentax 645z camera - but i don't know) - bending the light rays in the corner, especially with wider lenses, leading to blur and double / nervous "sharpness", and even smear with other branded lenses.

Or it is the lens itself (its optical construction) which bends the focus point/sharpness at the borders closer to the viewer (inward curvature at the borders).

I don't know.

I would say a bit of both. The A-lenses are from early 80s, the FA lenses from the end of the 90s. None of them where made for the later introduced digital sensor in the Pentax 645D and 645z.

(Nevertheless, I will test this lens anew - but on a tripod and without IS).

The 45mm ƒ 2.8 lens can be used - yes.

Just be aware of the borders are weaker - and it ain't the native Fujifilm GF 45/2.8 equivalent, or the GF 50mm ƒ3.5 pancake lens for that matter.

Still - it can be used, I would say. Especially if you focus a bit closer on subjects. When looking at the overall photo, you will likely will not see the weakness of the borders/corners. Only when you zoom in close, the degraded border performance becomes visible.

Still; it is definitely BETTER at the corners than the TTArtisan 100/2.8 2x Macro lens (of Fujifilm GFX) used at infinity. And better than many other 35mm lenses adapted on the Fujifilm GFX.

Well - for the 45mm focal length, i use the Tamron SP 45 mm ƒ1.8 VC lens anyway (or the native Fujifilm GF 35-70/4.5-5.6 zoom).

Both work with excellent optical quality when stopped down.