SMC Pentax-FA 77mm f/1.8 Limited Lens

Features
Handling
Performance
Verdict
Specification
This is the third of the Pentax Limited hand assembled lenses that are designed for film. Pentax have always offered some odd focal lengths and this 77mm equates to a 35mm-equivalent of 115.5mm when used on an APS-C format DSLR. This is very close to the 120mm portrait lenses that Pentax offered, so on digital the length has some potential. Being designed for film, and not a telecentric design, it will be interesting to see how this lens performs in the digital age and whether or not it lives up to its formidable reputation.

SMC Pentax-FA 77mm f/1.8 Limited Lens: Features

The 77mm is a hand assembled lens, made to the highest standards as is evident from its aluminium construction and the fine, precise quality of the engravings. The distance scale is viewed through a cut out as per the older M series lenses. A depth of field scale is provided and this also includes an infra-red focusing mark.

There is a built in lens hood, a very welcome feature. The lens cap is of a finely machined and finished aluminium that matches the lens construction. It fits securely on the lens, assisted by the green plush velvet lining.

There is an aperture ring, and this should be set to “A” for the purposes of retaining full functionality on the DSLR range.

The lens comprises 7 elements in 6 groups, suggesting a high degree of corrections for a lens of this type. Despite the metal construction, this compact 77mm weighs in at just 270g. The 9 bladed diaphragm makes an almost perfectly circular aperture which bodes well for the overall image quality that we might expect.

SMC Pentax-FA 77mm f/1.8 Limited Lens: Handling

The lens is compact and fits firmly and smoothly onto the camera body. The quality of construction is evident from the start and engenders confidence. The pull out lens hood is smooth in operation and has no tendency to move out of true, unlike some cheaper lenses.

The manual focusing is also smooth, albeit with a very different feel to the traditional silky smoothness of older conventional lenses. The technology has clearly changed, but is still totally satisfactory.

Focusing on the K-5 is fast and positive and no adjustment to the point of focus is needed on this sample at least. If required, lens AF can be fine tuned in the K-5 and some other recent Pentax DSLRs. Up to 20 lenses can be fine tuned and retained in the camera's memory.

77mm is a good focal length for a short telephoto and is suitable for selective landscapes, architecture, some close sports, portraits in particular and even wildlife to a limited extent. For many, portraiture will be an obvious choice and an area of particular interest. The lens already has a formidable reputation on film for this application, so we shall see if this holds up on a DSLR.

SMC Pentax-FA 77mm f/1.8 Limited Lens: Performance

Chromatic aberration chart
	Chromatic aberration is very well controlled, as we can see in the CA graph. It is unlikely to be seen even in the corners where, although not quite so well controlled as the rest of the field, it is much better than most zoom lenses and will not be a problem.

Flare is virtually non-existent and distortion almost eliminated as well. Around 0.03% pincushion distortion is irrelevant photographically and an outstanding performance.

MTF50 graph
		The MTF50 graph, describing the fine detail properties of the lens, shows us a lens with a very creditable resolution that peaks between f5.6 to f11 and is almost perfectly even across the field. This should mean retention of the finest details well into the corners of an image. This is ideal for the production of large prints and other critical applications.
MTF20 graph
		MTF20 describes more of the response to coarser textures and details and the overall contrast of a lens. This peaks at the centre at f5.6 and is almost totally even across the field at f8 and f11. This is a very high level of performance and shows in practice as bright, flare free, contrasty and colourful images. This lens grabs the attention, without a doubt.

In more pictorial terms, this is indeed an outstanding lens that gives superb detail, contrast and lovely skin textures. There is wonderful bokeh, aided by the almost circular aperture, and the 77mm holds up on digital just as well as film. Its fine reputation is entirely justified and intact.

Using f/1.8 has made it possible to greatly reduce the visibility of the bars in front of this caged owl, ISO200, 1/4000, f/1.8, 77mm (35mm equiv: 115mm)		The sharpness of the 77mm matches the sharpness of that vicious looking beak, ISO200, 1/200, f/8, 77mm (35mm equiv: 115mm)
Reasonable close ups can be obtained even though this 77mm does not focus down to macro distances, ISO800, 1/60, f/8, 77mm (35mm equiv: 115mm)		Virtually no distortion, excellent detail and sharpness, ISO200, 1/400, f/6.3, 77mm (35mm equiv: 115mm)
Accurate and fast AF makes fast moving wildlife shots possible, ISO800, 1/160, f/4, 77mm (35mm equiv: 115mm)		The 77mm has that indefinable quality of a fine lens, ISO200, 1/200, f/8, 77mm (35mm equiv: 115mm)
Lovely skin tones in this close up portrait of Lyndsey, ISO200, 1/160, f/8, 77mm (35mm equiv: 115mm)		There is plenty of contrast and bite in this colourful subject, ISO800, 1/60, f/6.3, 77mm (35mm equiv: 115mm)

SMC Pentax-FA 77mm f/1.8 Limited Lens: Verdict

Given the high construction standards, superb image quality and the compact construction this lens is a great prospect for portraiture and general travel. Its cost is higher than the average plastic bodied lens, but in terms of what it delivers I feel the price is a justifiable one. A Leica lens of the same quality would cost a good deal more, which is perhaps the way to look at it. There is everything to like about the Pentax 77mm Limited and the only thing to ask is how it can be afforded. This is one of the best Pentax lenses I have used.

A superb lens whose high price is entirely justified.

SMC Pentax-FA 77mm f/1.8 Limited Lens: Pros

High quality construction
Superb optical performance
Excellent handling
Useful focal length
Compact
Versatile

SMC Pentax-FA 77mm f/1.8 Limited Lens: Cons

May not be affordable for everyone

FEATURES
HANDLING
PERFORMANCE
VALUE FOR MONEY
OVERALL

SMC Pentax-FA 77mm f/1.8 Limited Lens: Specification

Price	£778.99
Contact	www.pentax.co.uk
Focal Length	77mm
Maximum aperture	f/1.8
Minimum aperture	f/22
Angle of View	31.5 degrees
Construction	7 elements / 6 groups
Focusing Range	0.7m - infinity
Magnification	0.14X Max
Filter size	49mm
Mount	Pentax K-AF
Weight	270g
Dimensions (Length x Diameter)	48 x 64mm
Kit Content	Front cap Rear cap Soft case Special Features Built-in lenshood