Pentax 645 FA 200mm f4
I’m still living out of a suitcase, but got my hands on my used Pentax 645 FA 200mm f4, which has been sitting in storage for a while. It represents one of the things I love about the 645Z, namely that you can pick up lenses like this for relatively affordable prices. This one cost me £240 ($360) on ebay about six months ago and that’s roughly what you would pay for a much more modest used optic like a Sony FE 28mm f2, or perhaps a decent stabilised kit zoom lens from Canon or Nikon. The difference is that this Pentax lens will not lose any more value and it is built to solid, professional standards. But is this ‘old’ lens any good?
Some of you may have read my 645Z reviews and there was quite length commentary about the various Pentax 645 lenses available here. The Pentax 645 FA 200mm f4 has a mixed reputation (more on this later) and is one of the best value lenses in the entire line up. Manual focus ‘A series’ examples go for about £100/$150 or less in the UK, whereas autofocusing FA versions are normally in the region of £300-450. You can get both versions for very low prices from Japan or South Korea, with A series versions selling for less than $100 in some cases.
How useful is such a lens? Well, its certainly going to be less generally appealing than 90-120-150mm for most people; however, 200mm does partner very nicely with the 120mm focal length, which is very popular. 120mm is especially popular with Pentax 645 users, because the 120mm Macro is universally regarded as one of the best lenses available for the system, even now. The angle of view of the 200mm on the 645D/Z is equivalent to 160mm on Full Frame, but of course it remains a 200mm in terms of depth of field. With such a focal length, an aperture of f4 is going to give shallow depth of field. It is therefore ideal for head or head and shoulders portraits. However, this focal length is also very useful for landscapes, which is what I will be using mine for.
Here are some basic statistics for the Pentax 645 FA 200mm f4:
Dimensions: 75mm x 120mm
Filter thread: 58mm
So, as you can see, it is not massive or especially heavy. By way of comparison, the Canon 24mm f1.4 L II is 650g and the Sigma 50mm f1.4 ART is 820g.
With a 58mm front filter, it is also cheap to cover with a UV filter.
Build Quality & Handling
Here is is predictably solid and indistinguishable from other Pentax 645 FA lenses. It is clearly built for decades of professional use and will last for more decades I am sure. There isn’t much to say about handling, because again it is the same as other FA lenses. The Pentax 645 FA 200mm f4 uses a push-pull (back and forth) clutch in the focus ring to engage/disengage AF and it works fine, although it does feel a little agricultural/clunky. Manual focus is smooth and pleasant to use. It isn’t going to give you the same tactile pleasure as a Leica or Zeiss optic, but it feels dramatically more solid than most modern lenses today.
It’s pretty snappy, buzzy and typical ‘645 FA’. It also seems fairly accurate and perfectly usable in general use; however, my copy is front focusing somewhat. This is not a fault of the lens and can easily be dialled out by using the autofocus micro-adjustment facility in the 645Z. I did not have time to do this properly, so I tested the lens using manual focus and live view. This meant that I was seeing what the sensor was seeing and so perfect focus was assured.
For those not familiar with such things, a mismatch between the alignment of the sensor and the alignment of the lens occurs with a great many modern optics and bodies. It is the product of manufacturing tolerances and therefore its essential that all users of DSLRs are aware of it and know how to adjust it with their cameras. Camera and lens manufacturers are getting better at tightening up tolerances, so that when ‘mismatches’ occur, they are minor, but absolute whoppers do still occur.
With most FA lenses being old and built during the time of film era tolerances, many if not most need some degree of adjustment to achieve perfect focus on one’s 645Z/D. This is easily done through the menu system on the camera body. Making adjustments of this kind is essential for DSLR users, because very often a lens that appears to be ‘soft as hell’, becomes ‘sharp as a tack’ when adjusted properly. However, there are a huge number of owners who are not aware of this issue and how to resolve it.
I suspect many/most of the bad reviews one sees for the the Pentax 645 FA 200mm f4 are caused by one of the following:
- People shooting them on film bodies (where there has been no way to dial in autofocus micro-adjustments) and having a body-lens mismatch. Although film is much more tolerant than digital, the thickness of the emulsion will not absorb all errors.
- Pentax 645D users who are not aware of AF fine tuning AF (the 645D does not have live view, which helps people to see what is going on with focus problems).
- The odd, rare, total lemon of a lens!
There will clearly be some not so good copies out there, but medium speed medium telephoto lenses of this kind are actually very easy to make. I therefore strongly suspect most Pentax 645 FA 200mm f4 copies are fine and that the majority of issues are due to the requirement to dial in AF micro-adjustment. The general ‘internet chatter’ suggests that tolerances are looser with this lens than others, which are known to be very consistent (120mm Macro, for example).
Here is a comparison to show the ‘mismatch’ in my lens-body system. Note that at infinity the error was much larger, but at medium distances like this, the lens might just be described by someone as ‘lacking bite’.
Note that all images are 1500 pixels wide, unless otherwise stated. The weather was dead flat, with no directional light, or contrast, so this will invariably make the lens look worse than it really is. I used ISO 800, because of significant wind and the need to maintain shutter speed even on the tripod. ISO 800 on the 645Z is impossible to distinguish from 100 in terms of resolution, for the purposes of this test.
Chromatic Aberration (CA)
This is a clear weakness of the Pentax 645 FA 200mm f4. It produces quite bad CA around high contrast edges. For colour work this could very well be a show stopper for some users, with this quite possibly being the worst CA I have seen on any of my Pentax 645 FA/A lenses. Much of it can be removed in LR using the sliders, but not nearly enough to produce entirely clean results. This is typical of longditudinal CA, because it is purple in front of the plane of focus and green behind. In bad cases, one would need to use a brush de-saturate these colours locally, after using the general adjustments in Lightroom. Still, with some care it remains very usable and would only be a real pig when shooting under challenging conditions for CA. For a B&W shooter like me, its not an issue 🙂
It is very pleasant, but not stunning. This isn’t a Canon 135mm f2 L, or 85mm f1.2 L; however, it offers plenty of softness for general portrait shooting and I would have no hesitation using it in this regard. With it being an AF lens, it can be used nicely handheld on location, as well as under more controlled studio settings. I chose the below scenes, because I knew that the branches and ivy behind the subject would be a hard test for any lens, but it has done well. My gut tells me the 150mm FA f2.8 would have done a touch better, but not by much of a margin.
Resolution, Contrast & Colour
This surprised me. It’s as sharp as a tack on centre wide open. By this I mean the improvement upon stopping down, on centre, is extremely hard to see because it is already blistering at f4. There is just a very slight lift in contrast and resolution from f4-5.6. It gets no better from there and you need to look very closely indeed to see it at all. In normal use, it is razor sharp wide open and does not improve (because it does not need to).
Around the edges of the frame at f4, there is a slight loos in perfect crispness, but it is still very good from corner to corner. This slight softness diminishes as you stop down and the lens peaks at about f8 or f9. It remains supremely sharp at f11, but starts losing a touch due to diffraction at f16 and increasingly so beyond this point. This is what you would expect from a lens without all the modern aspherical and extra dispersion elements. The Pentax 645 FA 200mm f4 is old school, but that brings certain benefits….
Contrast is again typical of Pentax FA lenses: medium. Colour is the same. It is an altogether more muted look compared to current ‘digital era’ lenses. This lens draws fairly gently and neutrally and, again, I really like it. IMHO, this is a much better starting place for B&W compared to the crisp perfection of many contemporary primes. You can crank the contrast up in post processing, but it is more difficult to shed ‘bite’ and perfection from super duper lenses to make a gentler looking image. All of this means you are looking at a lens that gives less colour saturation, less contrast and less ‘snap’ than the best testing FF lenses, but arguably gives some people more of what they like to see in a photo. Again, resolution is ample, but it is gently delivered and not ‘in your face’. For those who like more contrast and saturation, here is a scene that I adjusted in Lightroom (lighting was still flat of course) just to see what happened to colour and contrast with this lens under flat lighting:
In my opinion, this lens is a genuine bargain. It possesses roughly comparable optical performance (albeit at one further stop down) to the Pentax 645 FA 150mm f2.8, but at half the price (or less) on the used market. For dedicated landscape shooters on a budget, this is arguably the one to get. The 200mm pairs nicely with the 120mm focal length, giving two very useful lenses that are longer than standard. For those who own the Pentax 645 90mm f2.8 DFA Macro, the 150mm f2.8 FA is probably the better match in focal length terms (but a more expensive choice). The superb Pentax 645 FA 80-160mm f4.5 produces prime-like results, but it requires 1.5 stops smaller apertures to achieve it. The 200mm f4 also performs much better at f4 than the zoom does at 160mm and f4.5.
Hopefully those of you wondering how a 51 MP 645Z outfit could ever makes sense in light of the vastly cheaper 42MP Sony A7R II, maybe now you will understand: used 645 legacy lenses are much cheaper and they draw differently. Lazier non-aspherical lenses on the bigger sensor produce a look that is quite different to the A7R II and the likes of the Sony 90mm f2.8 G Macro, or even 70-200mm f4 OSS zoom. Don’t get me wrong, I love the Sony FE system, but for B&W landscapes, I’d rather be using the Pentax 645Z and 20 year old FA lenses. Some of that comes down to the body, but it is equally down to the lenses. If you’ve come from a darkroom background, you’ll likely know exactly what I am talking about. If you haven’t, its definitely something worth researching.
Lenses have become ‘better’ technically, but something is being lost along the way. Thankfully the 645z is rather like the A7 series from Sony in that we can mount old lenses and have the best of both worlds. The big advantage of the Pentax 645z is that we can mount native mount ‘old school’ wide angles, with either manual or autofocus! With the Sony FE system, you can use vintage wide angles, but you will need to use third party lenses and an adaptor. Because all the FE lenses are new, most have that very modern look.
Both are great systems, which is probably why I own… both; however, if you are a B&W fanatic, this super cheap Pentax 645 FA 200mm f4 lens is another reason to strongly consider the Pentax 645Z. You get bags of resolution, along with nice ‘n mellow old school results.
P.S. You can find very useful date and user reviews of this lens and other Pentax lenses here on pentaxforums.com.