I’m gradually building up a kit around the Pentax 645Z, which went on its maiden voyage to Iceland in May this year. On that trip, I used a manual focus 80-160mm A series lens, which I picked up of ebay for peanuts. It performed pretty well overall, although I did notice some optical asymmetries at the long end of the zoom (that will be specific to my individual copy). At narrow apertures it was not a big problem, but at middling apertures it bothered me and so I have been wondering what a better copy might be like. One other issue with the 80-160mm A is that the zoom mechanism will relax when you point the camera steeply upwards or downwards (I understand this is not specific to my copy, but general to the design). This means that the focal length changes. Its certainly not going to bother everyone, but in Iceland it annoyed me on a number of occasions, so I wondered if an autofocusing Pentax SMC FA 645 80-160mm f4.5 would be better for me, because these do not ‘trombone’.
On top of these two issues, I was also surprised to find that I missed having autofocus a more than I thought I would. Shooting with a 80-160mm on the Pentax 645Z is nothing at all like a Leica M (funnily enough). Correct focus takes much longer to find and needs to be much more precisely adjusted due to the longer focal length and massive resolution of the camera, which shows up errors mercilessly. Its one thing to shoot landscapes, but if you have subjects in the frame that might conceivably move back and forth (and so result in focal length changes as well as focus), then the A series lens might drive you crackers. It is a lens that changes focus when you alter focal length, so you are often toggling back and forth from focus to zoom. When I was focusing these birds, I originally worked with the 80-160mm A, but never quite got ahead, so had to revert to the FA 75mm, resulting in the image shown.
….So I bought a second hand Pentax SMC FA 645 80-160mm f4.5 lens from Germany (on ebay) to see if the grass might be greener on the other side (and it is).
Please note that all files shown below are 1500 pixels on the long side and have had no post processing applied other than my standard sharpening (unless otherwise stated).
Build Quality & Handling
You will be astounded to hear that its exactly the same as the Pentax SMC FA 645 150mm f2.8 I tested recently. It is built like a solid piece of professional equipment. It has no frills, it conveys a certain crudeness that is to be expected considering its age and lack of a Zeiss or Leica label, but you’re left with the impression that it will go on working for eons. It weighs a hair over 1Kg, so has some real heft to it, but it is mostly made of metal, so no surprise there. Putting the twist on hood on does require more force than you’d expect with a 35mm/FF lens and it snaps into the locked position with quite a ‘thunk’. This lens is like the 645Z: it’s a tool. If you’re looking for ‘slick ‘n pretty’ you’re probably better off looking elsewhere.
1010g, 77mm front filter thread, well made twist on hood. Despite its ridiculously long name, the Pentax SMC FA 645 80-160mm f4.5 is all very straight forwards, really.
With regard to Contrast & Micro contrast there are no surprises. It is absolutely what you might expect if you have used other 645 FA lenses: medium contrast on the 645Z with good, neutral and natural colour. Micro contrast appears to be very good and overall there is nothing to complain about if you are happy with this look. If you want more juice, you can crank things up in post processing, but I personally like the more relaxed feel of 645Z + Pentax vintage lenses. It comes down to personal preference and I like the gentler look, because it better suits the way I like my images to look (a bit more old school). It is much harder to back off super contrasty files in a convincing way, especially if shot in very high contrast lighting.
Resolution is impressive with the Pentax SMC FA 645 80-160mm f4.5 most of the time, especially for those who will be using this for landscape work.
**Please note that the long string of test shots are shown at the bottom of this post**
Wide open, there is a certain amount of glow to this lens. This is most apparent at the long end (160mm) and wide open, but is still present at the wide end (80mm), although more visible in the outer field.
By f5.6, the lens is performing very well on centre (at or close to peak) with bags of local contrast, but the corners will not yet be at their best (as one might expect). This is true at all focal lengths, but more so at the long end.
By f8 the lens is still not at its best apart from right in the middle of the zoom range, where I found it was performing extremely well at f8 right into the corners. At 80mm and 160mm, it is still a little short of its best overall. Regardless of focal length, central performance is always stunning at this aperture.
By f9-11 roughly, this lens peaks in terms of overall performance at 80mm. This is where there is a largely irrelevant reduction in central performance but the corners do just tighten up that little bit. At 160mm, f11-f13 is where I feel this lens is at its best for landscape use.
By f16 there is noticeable diffraction related softening and its clear even in the corners compared to the optimum apertures. If you are making huge prints, it will present itself as a subtle lack of bite, but for smaller prints i.e. A2, where there is resolution in reserve, you probably won’t notice unless making a point of looking. Besides, sufficient depth of field is usually more important than reductions in technical perfection. I would have no hesitation using this lens at f16 or f18 if I needed the depth of field.
It is reported that there is some field curvature present with this lens. While I have been unable to test this fully to date, I can only say that at medium-far distances there does not appear to be much to worry about. With this being the case, if curvature does present itself at longer distances I am very confident that it will be manageable by selecting ‘landscape appropriate’ apertures i.e. f11-f13. It may mean that you cannot do what you might with one of the best 35mm/FF primes, which is shoot a distant landscape at f5.6. That said, there aren’t going to be many medium format shooters who would have such expectations, however.
In sheer resolution terms, I was surprised to see it compete surprisingly well with the 150mm f2.8 prime at middle apertures. The Pentax SMC FA 645 80-160mm f4.5 is reputed to be at its weakest at 150-160mm, but I found my copy was strongest in the middle focal lengths and actually very respectable at both ends, but with a slight reduction compared to the central sweet spot. All that happens is the edges and corners are not quite as well behaved at wider apertures at the ends of the zoom range. To rectify this, it just takes stopping down a touch more to pull the corners into line (as explained above). I would say, however, that the lens is a less strong at 160mm than 80mm. All in all, phew…. its very good in my book and certainly capable of producing large detailed prints from 645Z files.
Chromatic Aberration (CA) appears to be averagely well controlled. I shot quite a few test shots and saw next to no CA most of the time, but if you push it hard (as I did in the below file, burning in the sky for easier reference after capture) CA will sprout up. This performance is no worse than I find when shooting many brand new Sony Zeiss FE lenses on the A7 series. Tick the little box in Lightroom and the CA that crops up in ordinary use is taken care of, but it cannot cope with the ‘full-on’ variety as shown below.
Bokeh is not something I really tested, but from the frames I shot to see if I needed to apply any AF micro adjustment (which I did not), bokeh looks fine. It certainly did not reveal any nasties, such as ‘wired/caffeinated’ bokeh.
Yes, this lens can be made to flare. Like the Pentax SMC FA 645 150mm f2.8, it is not a super modern Zeiss lens by any stretch of the imagination. It will kick out veiling flare like that’s its job if you point it towards a large expanse of bright grey sky. I am OK with this, because its in keeping with what I want from the lens. One of the reasons why I went with the 645Z system is because it allows me to use lenses that resolve very well but are not perfectly well behaved and which are therefore not boring. It’s like people. We all like to have friends that get a bit too drunk, make fools out of themselves once in a while and wake up with a hangover that makes them look 15 years older than they really are. Who are you more excited to see for a slap up brunch the day after a party; the squeaky clean ‘goody two shoes’, or your train wreck buddy who has good reason to feel ashamed!? Perfection really can be boring, but these Pentax lenses are far from being ‘character lenses’. They are technically very good and ‘neutral’, just not so well behaved as to limit your options to an etched perfection that’s hard to override.
Autofocus is exactly the same as in the 150mm f2.8: fairly swift, decisive and accurate, but noticeably ‘buzzy’. It has the same sort of ‘bzzzzt’ sound I associated with my 20 years old Pentax MZ-5, but the Pentax SMC FA 645 80-160mm f4.5 is more decisive by far. It does sometimes hunt, but most of the time it grabs focus with conviction.
Price varies considerably. They can be picked up for about £300/$450 from Japan quite easily and often for a bit less, but in the UK we have to pay import duty and VAT, which on top of the transit time and cost made less sense than waiting for a decent copy closer to home. In UK camera stores with a shop front, used prices are normally around the £500-700+ mark, but can be found for less. I picked up mine for about £370 from Germany complete with caps and hood. Thankfully I got an excellent copy at the same price as a new Sony FE 28mm f2, which I consider to be a real bargain.
Pentax SMC FA 645 80-160mm f4.5 Conclusion
When placed on a very high resolution digital body, with the expectation of large prints, it’s perhaps better to talk about how good lens models can be instead of how good they are. This is because sample variation means that individual samples don’t always live up to the potential of the design. Based on what an excellent copy can do, this lens would appear to be a great proposition for 645Z and 645D owners. I have been unable to detect any particular concerns with this lens and it covers an enormously useful focal range equivalent to approximately 65-125mm in Full Frame/35mm terms.
This lens is going to be central to my kit bag. I used the 80-160mm A series lens a lot in Iceland and this one performs more consistently right across the zoom range, the AF is definitely going to be handy for quick grab shots (yes, I often shoot the 645Z like this) and it won’t trombone when pointed upwards or downwards. Its a great lens and highly recommended, but do not be surprised if your first copy is not perfect, so ensure you have the right to return it if all is not well. With an example performing as it should, I’d stick to f9-13 for the 80mm end (where possible) and f11-f16 for the 160mm end, for landscape work. You can do fine at wider apertures, but where you need best sharpness on the edges of the frame, these apertures will be a very good compromise between depth of field and diffraction.
I am going to recommend this lens over and above the manual focus A version for all the reasons stated in this article. It may be almost double the price on the used market, but for that you get a more polished and far more flexible lens, with a quality lens hood thrown in.
Hold onto your underwear, test shots coming up – Click Below for Next Page….