SMC Pentax 77mm f/1.8 Limited
When ever you ask a Pentaxian what lenses you should get, one of the answers will certainly be to buy the Limited lenses. They have a series of DA Limited lenses designed for digital sensors, but many swear by the older FA Limited lenses. The FA 77mm has a legendary reputation, but is it deserved?
The FA 77mm f/1.8 was released in November of 1999. The focal length was chosen as many felt 85mm was a little too long for 35mm to use as a portrait lens, and they wanted to pick something in between 70 and 80mm. The focal length of 77mm was similar to the field of view of a human eye when looking at other humans. Also, 7 is considered a lucky number in Japan, so 77mm was a logical choice. 
Build and Handling
The build quality of this lens is amazing. The lens barrel is made of machined aluminum, and the lens hood is a velvet lined metal sleeve that slides out if you need it. The size is extremely compact compared to competitors offerings, where it is roughly the size of a 50mm f/1.4. It weighs in at 9.6 oz (270 g).
The manual focus ring is a knurled metal ring on the front of the lens. It turns while auto-focusing, but is set lower than the surrounding barrel as to not interfere with your hand if it is holding the lens. This lens retains an aperture selection ring as well.
The lens design is a modern, but traditional design with 6 groups and 7 elements. It uses high refractive and low dispersion glass to improve flare and coma common in older traditional large aperture lens designs. It uses Fixed Rear Element Extension to correct aberrations at close focus distances, and 0.7 m (2.3 ft) is fairly close minimum focus distance for a lens of this class.
So how does the FA 77mm Limited perform on the test chart? Read more…