Since the introduction of Pentax full-frame DSLR cameras, the range of new full-frame lenses has steadily, if slowly, increased. In the early stages, there was a huge amount of interest in older film-era lenses, as these are also full-frame and the amazing degree of backwards-compatibility of Pentax kit means that a host of good lenses are available on the second-hand market. Being designed for film cameras, some of these may be poor on digital, lacking the desirable telecentric design that digital cameras are suited for. But many are still excellent and very usable on the latest camera bodies. Here we have the SMC Pentax-FA 70-200mm f/4-5.6 Power Zoom lens, manufactured between 1991 and 2000, a workhorse of a lens in most ranges and a fraction of the cost of current offerings. This looks an attractive proposition, so let's look at how it handles and performs using the 36MP Pentax K-1 body.

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SMC Pentax-FA 70-200mm f/4-5.6 Power Zoom Vintage Lens Handling and Features

Being a modest maximum aperture of f/4-5.6 the lens is far more compact than most f/4 or f/2.8 designs, and also relatively light at just 465g. The lens barrel is accordingly svelte and the filter thread a very modest 49mm. There is a dedicated hood RH-RB 49mm, but missing here and in any event, it is a screw-in type, so has none of the advantages of current lenses with their bayonet fit hoods. A suitable snap-on hood was selected for use for this review.

There is a thin manual focusing ring at the front of the lens, quite free in action as is typical of Pentax FA series lenses and which can be experienced today in the current SMC Pentax-FA 50mm f/1.4 lens, which is still available new. We have no QuickShift facility though, so the camera will need to be set to MF for the ring to be used. The ring does rotate as AF operates, and the front element also rotates, making the use of, for example, polarising filters more difficult.

There is a plastic window revealing the distance scale, clearly marked in feet and metres, but no depth of field scale. We do have though two red markings for IR focus correction, one for 70mm and one for 200mm. Focusing is down to 1.1m or 3.6 feet, giving a maximum magnification of 0.25x, or 1:4. This is usefully close, one-quarter life-size.

There is a switch and button array marked P, A and AS and the part that will function today is the P setting, which allows Power Zoom. The zoom ring has two positions. Pulled back, it is a normal manual zoom action, smooth enough in operation. Pulled forward, revealing the words Power Zoom, and the ring is motorised. Depending on the degree of rotation three speeds of zooming can be selected. If this motor had been silent, then its usefulness in videography would be obvious, but unfortunately, no such concepts were considered at the time and the motor is quite noisy. Intriguing that current cameras should still be enabled to use it, but these days the same power contacts provide the current to drive AF motors in lenses so equipped.

Going back to the switch, there are some zooming tricks that film cameras could employ. So P = Power Zoom. A = Auto Zoom. AS = Set to select type of auto-zoom, using the button provided. These functions are Image Size Tracking, where a tracked subject is kept the same size as it moves through the frame and the camera zooms automatically to achieve this. Zoom clip memorises a zoom setting, which can be returned to at any time by pressing the button. Zoom effect will auto-zoom a set range for the typical zooming effects we see with longer exposures. All clever stuff, but with the K-1 only the simple Power Zoom setting will work.

There is a final clear plastic window that reveals the zoom setting scale, clearly marked at 70mm, 85mm, 100mm, 135mm, 170mm and 200mm.

AF is by screw drive and with the K-1 is blisteringly fast as well as blisteringly noisy. There is rarely any hunting and the lens whacks into focus virtually every time, but it is hardly subtle.

Optical construction is 10 elements in 8 groups, which is relatively simple compared to current lenses. No special elements either. The diaphragm comprises 9 blades, more than usual for a telephoto zoom of the era where we might have expected 7.

The bulbous zoom ring, typical of Power Zoom lenses, does make it look a little odd, but it all works very well. One point made very forcibly is that there are handling benefits from having a restricted maximum aperture and a fairly compact and light lens, so this is easy to use for long periods of time.