Pentax DSLR : Phenix 50mm F1.7 Review

Today i just want to make a short review about my favourite manual prime lens..the details are below :

1. Specifications

Image Circle : 35mm Full Frame
Focal Length : 50mm
Max Aperture : F1.7
Min Aperture : F22
Diaphragm Blades : 6 Blades
Angle of View : 47 degree
Front Element Rotation : No
Closest Focus : 0.45m
Filter Size : 52mm
Weight : 210 grams
Dimension : 63mm x 31mm

2. Build Quality

This lens build is par with pentax K, M, and A series prime lenses. It build with very tought metal. It is fully metal except the aperture ring and some part of the mount (see pic below). The focusing ring is very smooth and easy to rotate. It is very comfortable while focusing. The focus ring rotate 180 degree from minimum distance to infinity. This will make this lens is easy to facus and accurate. The lens barrel is not rotating when focusing and there is no problem using a CPL filter with this lens. The lens extand around 10mm when focusing (see comparison pic above)

3. Image Quality

Image quality is not much different when compare to FA50.4. FA50.4 are more contrast than this lens. This lens are design to use at wide aperture, so the sharpeness at wide open is very good. Add 1 or 2 stop more, the sharpness is excellent. The bokeh is quite acceptable and not much different with FA50.4 at F1.8 but FA50.4 still better. Below some sharpness sample at various aperture and bokeh comparison against FA50.4.

Bokeh test and comparison (Phenix 50.7 vs FA50.4)

In term of creamy bokeh, FA50.4 easily beat Phenix 50.7 but in term of sharpness, Phenix 50.7 win. (Phenix at F1.7, FA50.4 at F1.8 )
4. Distortion and Vignetting

Being a prime lens, this lens not show any visible distortion (maybe slightly) and vignetting also not visible (see using naked eyes) at all. So it has no problem with distortion and vignetting.

5. Chromatic Abberations (CA)

This is really surprising me. This lens control CA better than the FA50.4 lens. You can see it from the bokeh comparison above.

6. Conclusion

For conclusion, this lens is really stunning and excellent for what i have paid. I'va paid only USD30 for this lens and is great value for money. The only cons i found in this lens is this lens doesnt have auto focus (AF). That all. Other than that, EXCELLENT !!!!

7. Rating

1. Optical Quality ★★★★☆
2. Build Quality ★★★★☆
3. Value for Money ★★★★★