In Round 1, both the SMC Pentax-FA 1:1.4 50mm and the Fuji Photo Film Co. Fujinon 1:1.8/55 were impressive in their first round wins. The Pentax-FA 50/1.4 easily bested its opponent with better contrast, sharpness, and bokeh. The Fujinon 55/1.8, likewise, showed a refined bokeh between two nicely sharp and resolving lenses.

In Favor Of The Pentax-FA 50/1.4

Ease of Use

Without question, the fully-automatic (including auto-focus) Pentax-FA 50/1.4 mates with modern Pentax cameras better than does the Fujinon 55/1.8. The Fujinon 55/1.8, as I expanded upon in its Round 1 matchup, not only requires an M42-to-K mount adapter, but its lack of a Manual/Auto switch requires a modified one to boot. The native bayonet on the Pentax-FA 50/1.4 fits seamlessly and transmits lens data to the camera.

Among other differences, the Pentax-FA 50/1.4 can use matrix metering and P-TTL flash, whereas the Fujinon 55/1.8 can only use center- or spot-metering and does not support TTL flash. The Pentax-FA 50/1.4 also, obviously, supports auto focusing.

Low Light Capability

The Pentax-FA 50/1.4 provides a roughly two-thirds stop advantage in gathering light. Since there is essentially no difference in the overall image quality between f/1.4 and f/1.8, this means that compared to the Fujinon 55/1.8 wide open, you can feel free to shoot with faster shutter speeds or lower ISO with the Pentax-FA 50/1.4 wide open. Two-thirds of a stop might sound insignificant, but it can be the difference between a shaky picture at 1/40th second or a sharp one at 1/60th second. It is in demanding situations where the camera is on the cusp of hand-held shots where I find the real benefit of the f/1.4 and wider lenses.

Sharp and deliciously smooth bokeh at f/2.8, courtesy of the Pentax-FA 50/1.4.

Bokeh At f/2.8

The Pentax-FA 50/1.4 does indeed provide very nice out-of-focus rendering. It is at f/2.8 and smaller that some of the flaws common to this lens dissipate and place it in league with the great fast 50s ever produced.

The difference in aperture blades also plays a part at these apertures, with the 8 Pentax-FA 50/1.4 blades creating a more circular and hence more pleasant background than the 6 Fujinon 55/1.8 blades. The difference in aperture blades can be seen in the sample pictures here for the Pentax-FA 50/1.4 and here for the Fujinon 55/1.8.

Sharpness At f/2.8

The Pentax-FA 50/1.4 can be a bitingly sharp lens, and at f/2.8 it is resolving plenty of detail with high contrast. The Fujinon 55/1.8 proved itself to be a sharp lens as well, but I think the edge at smaller apertures goes to the Pentax.

In Favor Of The Fujinon 55/1.8

Build Quality

The Fujinon 55/1.8 is a metal lens, with a metal aperture ring. It has enough glass to give it weight without making it heavy, and it has enough size to give it a nice feel without making it big. The Pentax-FA 50/1.4, by contrast, is just a nice plastic lens. While it thankfully still does have an aperture ring, and has a nice amount of glass in it, it is still a member of the cheap-feeling-and-ugly Pentax-FA line of lenses.

Purple Fringing/Chromatic Aberration

It isn't that the Fujinon 55/1.8 is spectacular with lens aberrations, but rather that the Pentax-FA 50/1.4 at wide apertures is weaker. Some of the Pentax-FA 50/1.4's low light prowess is mitigated by the clear axial color and purple fringing that often shows at f/2 and wider apertures.

The Fujinon 55/1.8 does display aberrations, as can be seen in 100% crops here, but it seems that the higher contrast of the Pentax-FA 50/1.4 comes at a cost of overloading the sensor at high-contrast transitions.

An ordinary electrical fan provides a difficult subject for mitigating finging. This shot with the Fujinon 55/1.8 renders the scene fairly well.

This shot, taken with the Fujinon 55/1.8 wide open, is sharp and has decent bokeh.

Sharpness At f/1.8

As can be seen in the 100% crops of the Virgil's Root Beer bottle here and of the electrical fan here, the Fujinon 55/1.8 seems to be a touch sharper at f/1.8 than the Pentax-FA 50/1.4. Both of those samples were taken on a heavy tripod with 'mirror lock up' to minimize camera shake. The difference is more slight in the electrical fan, but is evident in both.

No Decision

Color

As mentioned in Round 1, the Fujinon 55/1.8 has a distinctly cooler color to its images.

Price

The Fujinon 55/1.8 is relatively scarce but can still be found inexpensively. The Pentax-FA 50/1.4 regularly sells for 10 times the Fujinon's price, but there is little debate that both offer distinct value for their cost.

Conclusion

The Fujinon 55/1.8 performed well again, taking extremely difficult subjects like chrome in stride. It is sharp at all apertures and has a decent out of focus rendering. However, it was overmatched by the Pentax-FA 50/1.4 in sharpness and bokeh starting at f/2.8, low light capabilities, and - importantly - ease of use. For the auto-focus sect among us, this contest was over before it started. Even for a dedicated manual focus user like myself, the SMC Pentax-FA 1:1.4 50mm proved to be overall the better lens, and will advance to the next round.

Feel free to check out my dedicated galleries for the SMC Pentax-FA 1:1.4 50mm and Fuji Fujinon 1:1.8 55mm.