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 ★★★★★

Pentax DSLR : Transform M Lens Into FA Lens

I have done this transformation about 6 months ago. For this transformation, I used Phenix 50.7 lens and FA28-80 lens. I have changed the Phenix 50.7 mount with the FA mount. Sorry I dont snap a picture during the process to show you.

Here is how the final image look like:

And here aare some test result at various aperture. Aperture was changed via body setting.

Pentax DSLR : DIY Split Screen for Pentax K-7

I have found very interesting DIY tutorial on how to make your own split screen for Pentax K-7. The working flow is quite easy and i think everyone can make it. Before you start you need :

• 1 split screen from slr film camera (you can buy it new from store or use split screen from unused slr camera).
• 1 original Pentax K-7 focusing screen for measuring purpose.
• Scissors
• Ruler
• Knife
• Sand Paper
• Blower
• Fiber cloth
• Pencil

Ok, now we already have all the tools to start the. Then we can move to the first step.

Step 1. Take your Pentax K-7 focusing screen and put it on the split screen. Use the Pentax K-7 focusing as a marker and then draw line using a knife on the split screen. Make sure you draw it properly.

Step 2. After you finished draw line on the split screen, cut it using scissors. Make sure you dont cut it through the line. Cut it outside the line and do it properly.

Step 3. Ok, now we have one split screen that size a lil bit larger than the original Pentax K-7 focusing screen size. Now we can move to the next step. Clean the tip of the cut using sand paper. Clean it until it size exactly same as the size of your Pentax K-7 focusing screen.

Step 4. After clean the tip of the cut, use blower to blow the dust. Then use fiber cloth to clean the split screen. Now our own split screen size is clean and ready to use.

Step 5. Then take a ruler measure and devide the split screen into 3 x 3 or 4 x 4 square depends on you. After measure, mark it with a pencil. After finished marking the split screen, draw a line through the mark using knife and ruler.

Here we are. Our own DIY split screen for Pentax K-7 is finish and ready to use. Now you can try it and have fun manual focusing using your Pentax K-7.

Pentax DSLR : Pentax K-X blur/soft focus problem report

Lately a lot of new Pentax K-X users reported that pictures come out from their K-X is not sharp or blur. There are still no accurate answer related to this problem. It could be problem from the hardware or firmware. But some forumers reported that the problem solved after they upgrade the firmware from v1.01 to v1.01.00.07. Apparently, after do the firmware upgrade, most of them still facing the problem.

There are two possibility that cause the problem. First, Shake Reduction (SR) mechanism problem and the second one is from the in-camera setting menu. Some said the problem occur due to the unaccurate SR mechanism. I dont know how true is it but from the specifications, the K-X SR mechanism should be better than previous pentax model.