I would probably call this a "summer outdoor lens" for either Pentax 645 cameras (with AF), whether film or digital - and of course I can adapt it on a Fujifilm GFX camera, as well. AF however will not function, and you have to set the focus manually.

It will be interesting, to see how it performs.

You may wonder why ?

I bought a third 645 FA lens ? Well, when I sent back the TTArtisan Macro lens to Amazon, I finally got back the money. From that I bought the FA 150-300mm zoom today, as it has a good reputation, and looked very good for the price at eBay in Japan. No mold, no haze, no seperation.

As of writing, the packakge with the needed adapter so that i can use them on my digital Fujifilm GFX mediumformat camera. Actually, i "cheated" with the adapter; it is a Fotodiox Pentax 645 > Canon EF adapter. and from there I adapt it to my existing Fringer Pro EF > GFX adapter.

This should ensure that the Pentax 645 lenses can be used on the Fujifilm GFX.

According to people at the Pentax forum

it is a very good lens, especially when stopped down to ƒ8 - it performs very well. This zoom has internal focus (IF), so it will not change size, when you zoom in or out. The ED stands for special glass, that keep down the chromatic aberrations and such.

As with all (film) mediumformat lenses - that is what you do; you stop them down 1-2 stops in order to get them really sharp. Often they peak in optical performance around ƒ11 on film. With digital sensors slightly less - but it can vary from lens to lens. At ƒ16 you get diffraction, making fine details blurry - that is a physical law. Film is slightly more tolerant in that regard (but not immune) and you may easily get away even with ƒ16.

Highly affordable

It was really affordable for me with a total price of 2500 SEK / 210 € from Japan - Swedish tax and shipping included. It is clear to me, that most Pentax 645 are a bit cheaper than Pentax 6x7 lenses. So, I enjoy the lower price level. OK, some Pentax 67 lenses are still very affordable, while others are a bit elevated - but nothing outrageous, except the Pentax 67 SMC 75mm ƒ2.8 AL lens, which has skyrocketed to 3000 €. Probably because of the bright aperture. Well, choose the 67 SMC 90mm ƒ2.8 instead - which costs a fraction of the former. Also a very good performer.

Also nice was, that the zoom lens has a 77mm Ø polarization filter added. Mine is so old and worn after 40 years, but i never felt it was sexy to spend money on a new (nowadays far more expensive) Polfilter today.

The Filter Saga - Fairy dust into people's eyes

Overall many filters have gotten very high in price, i have noticed. It is like fairy dust all over again (e.g. people think they need a bunch of very expensive filters). Truth is - most of them you never need. Maybe it goes like that; for every second generation - you can pull off that trick on people - and people will buy it, thinking it is a necessity.

It is not.

In America it seems that almost everyone buys those stupid UV filters, for example. I get it - it is good for protection in dusty or excessively wet weather. At the same time - it does degrade a stellar (expensive) optical lens into becoming more average performing one. Especially on digital cameras and telephoto lenses. The lens hood is perhaps the most important part protecting you from bumps (and degrading stray light) - not a filter.

Equivalent focal range / angle of view

On a digital Pentax 645z, as well Fujifilm GFX - this 645 Pentax 150-300mm zoom lens becomes equivalent to a 120-240 mm ƒ 5.6 lens.

On a film based Pentax 645 cameras - the zoom gives the perspective of a 90-180 mm lens; e.g. going from portrait to moderate telephoto.