Pentax Q Review

Image Quality - Other

On the night shots of the fountain we noticed a markedly lack of detail in the water drops in the Q images. Those images were taken with the electronic shutter so we went back in daylight and took shots with the electronic shutter as well as the leaf shutter.

Effect of Shutter Type (100% Crop)

Click on an image to enlarge

There was no difference between the two kinds of shutter and there was plenty of detail in the falling water. The images are JPGs, cropped and with some contrast added.

The Pentax Q JPG files were consistently smaller than the Olympus files. The Pentax simply compresses the images more than we are used to at a three star setting. We therefore decided to once again compare RAW and JPG.

JPG vs RAW (100% Crop)

Click on an image to enlarge

While the difference is subtle, there is less detail in the JPG shots. This can be seen in the back of the chairs and the flower petals. We still recommend to use JPG for most shotsso as to avoid the hassle of having to do the lens correction in post processing (we skipped that step in the above RAW samples).

Purple Fringing and Flare

We we not able to provoke any purple fringing by shooting tree leaves and twigs against a bright sky which is usually a safe way to provoke fringing. We did observe some flare when the sun was just outside of the frame - had we had a lens hood available that would have suppressed the flare in most cases.

Shooting directly into the sun with the 01 Standard Prime produced a reflection of the sun most likely due to the strong light being bounced back from the sensor into the lens and reflected back again onto the sensor. It could be that the light was reflected off of the diaphragm which was set to f/5.6, in other words it was almost closed fully down.

sensorreflection01 Standard Prime Lens, f/5.6, JPG

01 Standard Prime vs. 02 Standard Zoom

These two lenses are the only "serious" lenses in the current lens line-up. They are auto focus, have built-in leaf shutters and neutral density (ND) filters. The focal length of the prime is 8.5mm and is thus covered by the range of the zoom. So what is the justification for the prime lens? We found image quality virtually identical as per the example photos below, so what's left in favor of the prime is it's one and a half stop faster maximum aperture of f/1.9 where the zoom at 8.5mm focal length is f/3.5, and much smaller physical size.

Fountaindaylightzoom Fountaindaylightprime
Zoom at 8.1mm, ISO 125 f/5.6, RAW (3.4 MB) 01 Prime, ISO 125 f/5.6, RAW (3.4 MB)

Pentax Q vs. K-7

Our final comparison is the Q versus an APS-C sensor represented by the Pentax K-7. This is a 14.6 MP sensor, reasonably close to the 12.4 MP sensor of the Q for this comparison. The images were shot in the RAW DNG format and processed with similar settings in Adobe Camera Raw. To match the depth of field of the Q we would have to use f/22 on the K-7, but diffraction would set in at that aperture so we settled for less depth of field and used f/11. As we saw earlier diffraction is not an issue on the Q at f/5.6.

Pentax Q with 01 Standard Prime at f/5.6, ISO 125 (click the image for a 100% crop (600 kB))
Pentax K-7 with FA*28-70 at 31mm, f/11, ISO 200 (click the image for a 100% crop (800 kB))

At the low Web resolution of the images above one the K-7 image appears only slightly better than the Q. However, at 100% resolution the K-7 has a significant edge over the Q even if we didn't use a prime lens on the K-7.

Finally we will compare the 02 Standard Zoom at 7.5mm, 10mm and 15mm with the FA*28-70mm zoom at corresponding focal lengths. The images were cropped but not re-sized. They were shot in RAW DNG and processed similarly in Adobe Camera Caw. Click a thumbnail to download a 100% crop.

Q02 K28mm
Q with 02 Standard Zoom at 7.4mm f/5.6 ISO 125 (2.4 MB) K-7 with FA* 28-70mm zoom at 28mm f/11 ISO 200 (4.7 MB)
Q10mm k37mm
Q with 02 Standard Zoom at 10mm f/5.6 ISO 125 (2.7 MB) K-7 with FA* 28-70mm zoom at 37mm f/11 ISO 200 (4.8 MB)
Q15mm K58mm
Q with 02 Standard Zoom at 15mm f/5.6 ISO 125 (2.3 MB) K-7 with FA* 28-70mm zoom at 58mm f/11 ISO 200 (4.5 MB) PentaxForums @PentaxForums News | Reviews | Forum

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