Extreme wide angle lens for the 645 format. This lens was introduced in 2015 and replaced its FA counterpart. It retained the optical design of the FA lens but with some tweaks of the aspherical elements and the aperture blades became rounded for a nicer bokeh.
The lens elements are now HD coated for increased contrast and reduced flare and ghosting. The front element has SP coating which repels water and grease.
The lens has an aperture ring which makes it fully backwards compatible with 645 film cameras.
The petal-shaped bayonet lens hood has a removable piece which makes it easier to adjust a circular polarizer.
It's a winner. My rating is a solid 9.5 but rounding up in the absence of 1/2 point scores.
My favorite lens for the 645D and Z has been the A35 for it's amazing IQ, well controlled aberrations, and value price in the $300 neighborhood. On a whim, I decided to take a chance on the recent upgrade to the D FA version and am pleasantly surprised.
Having the benefit of doing some side by side comparisons to the A35, I am confident this lens is even better than the trusty older lens. Center sharpness is very good at f/3.5 and then by f/5.6 is excellent. Falls off above f/11 as might be expected. Flare handling is just fine when shooting into the sun or a strong oblique light source.
I happen to use 82mm polarizers for my 300mm, so the larger filter size is not a deterrent.
The first sample of this lens had unacceptable lateral CAs. The replacement still has more CAs than I would like under the most difficult conditions, and more so with slightly out of focus black to white edges. But in most real world scenes not overly noticable and can be corrected in post-processing. Sharpness is however very good overall and exceptional at abut f/8 is and softening notably by f/16. I shot a series of landscapes at f/11 and was happy printing these 44" wide directly out of lightroom. I have also been pleased with colour, and contrast. Flare and ghosting appear to be well in control from limited examples.
This is not a particularly large lens (570g and about 90mm length/width). Comfortable to use on the 645z. Certainly not light, but carrying it about on the camera (around neck and in hand) for a couple of hours was no problem. The auto/manual focus switch is actually a clutch (no full-time manual focus while in AF) switching manual to AF is by by pulling/pushing the textured focus ring at the end (which took some finding out without an instruction book). In manual action is smooth and I had no difficulty achieving acurate manual focus in live view. I have not found it necessary to make any micro adjustments for focus.
This is a 35mm lens (For the 645d/z that is equivalent to 27.5mm on 35mm full frame). That is wide but not excessive and very usable but the price seems a little high particualrly at UK prices that are pound for dollar and therefore about 25% more expensive than USD. I often shot at 24mm on my DSLR so this is not quite as wide as I am used to, but the two wider Pentax lenses costs a lot more so I'm simply learning to work with the restiction.
Shooting at f/11 there is some barrel distortion, but you probably only want to correct it if there is something that makes it stand out. I cannot report if distortions are better than the predecessor. Exposure does fall of a small amount towards the corners. I have not measured it but it is perhaps just a small fraction of a stop and barely noticable in good lighting. Lightroom has a profile for the lens and handles the adjustments fine.
The filter thread is 82mm, which is slightly annoying since 77mm is far more common, and looking at the front element I can't help think there was no real need for this diameter. This isn't a problem for the square filter sets (just a minor expendature on a new wide angle Lee 82mm adapter) but it can be helpful to use the right size polarizer so it can fit inside the supplied lens hood, so more expendature for many people, but if you are buying an expensive lens you want top quality filters to go with it! The lens hood does have a removable section at the bottom so you can turn the filter and the cap can easily be removed an replaced with the hood in place.
The lens arrived with hood, cap and pouch but strangely this lens did not come with an instruction manual which I assume was an oversight.
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