The Pentax Q can be called the smallest interchangeable lens camera, outside of some toy or spy cameras which barely take pictures. It has a correspondingly small sensor size, common to many compact digital cameras.
|Pentax Q with Pentax-01 Prime Lens (47mm equivalent)|
The Sony NEX-7 is one of the enthusiast level mirrorless cameras available from Sony. Sony produced the first mirrorless APS-C sensor camera with the first generation NEX-3 and NEX-5 cameras, and the NEX-7 improves upon that formula with a digital viewfinder, more control dials, and a powerful 24 megapixel APS-C sensor.
|Sony NEX-7 with Sony 18-200mm Zoom Lens|
|Pentax Q pictured next to a Sony NEX-7. The NEX-7, which is a small camera itself, completely dwarfs the Pentax Q (of course, the giant lens helps too).|
The Nikon D600 can claim to be the first affordable full frame DSLR. It has a full frame sensor (equivalent to 35mm film size) in a body that is barely larger than the popular Nikon D7000. It is currently the smallest and lightest full frame DSLR on the market. Also has a 24 megapixel sensor, believed to be sourced from Sony, but it is full frame so the pixel density is lower than the Sony NEX-7.
|Smallest Full Frame DSLR ever doesn't mean much when sitting next to a Pentax Q.|
For some quick statistics, the Pentax Q with the prime lens attached weighs approximately 240g.
The NEX-7 weighs approximately 350g, and the 18-200mm lens as pictured in this review weighs 524g. To be more fair, the Sony 35mm F/1.8 prime would be the more similar lens to compare with, and that would weigh 155g to give a combined camera + lens weight of 505g.
The Nikon D600 body only weighs 760g, and the Nikon 50mm F/1.4 lens weighs 290g for a total of 1050g.
So in summary, for equivalent approx 50mm shooting with prime lenses, the three combinations come in at 240g for the Pentax Q, 505g for the NEX-7, and 1.05kg for the D600. Or approximately double for each size up.
So how do they compare in photo quality?
For the purposes of this shootout,
- All three cameras were mounted on the same tripod, shooting at the same target.
- At a focal length of 50mm equivalent (the Pentax-01 prime is 47mm equivalent, the NEX-7 with zoom lens was set to 32mm, and the D600 has a 50mm lens).
- At base ISO (ISO 100 for NEX-7 and D600, ISO 125 for Pentax Q).
- Aperture F/4 for Pentax Q and D600, F/4.5 for NEX-7. Hopefully to balance the playing field for lens quality, but NEX-7 has disadvantage here due to using a zoom lens.
- Crops taken close to centre of photo to minimise lens quality issues.
- All images shot in RAW format, processed in Lightroom with no adjustments, and exported to JPG.
With the full image resampled down to 1600px width, there's not a lot to separate the three cameras. There's an obvious difference in colour temperature with the Pentax Q, but that's something that's easily fixed in post processing. With all three cameras, the text on the Nikon lens is just readable. The fur on Scooby's paw does seem a little bit sharper on the D600 and NEX-7, but not obviously so.
Next, we have a closer look with a crop around the subject items. This represents an 80% crop of the Pentax Q, and approximately 50% crop on the NEX-7 and D600, when the crops are viewed at 1600 pixels width.
|Nikon D600 - 50% crop|
|Pentax Q - 80% crop|
|Sony NEX-7 - 50% crop|
At this size, the Pentax Q is obviously inferior, with blurry text on the Nikon lens and the Staedtler pens box. With the slighter brighter exposure on the D600, it does appear to be sharper than the NEX-7, but actual visible level of detail seems to be similar.
There is also a fair bit of false colour noted for the D600 and NEX-7 shots. The text should be black on the Staedtler pens box, but quite a bit of blue is observed in the photo.
We go for a more aggressive crop next, to see if we can identify any further differences in detail. This crop around the Gran Turismo booklet represents a 200% crop on the Pentax Q, and approximately 125% on the NEX-7 and D600.
|Nikon D600 - 125% crop|
|Pentax Q - 200% crop|
|Sony NEX-7 - 125% crop|
The Pentax Q already lost in the last comparison, but for the sake of the comparison we keep going. With this last crop, the Q is completely blurred, with most of the text unreadable. The gran-turismo.com is ok, as is Polyphony, but that's about it.
Again, the D600 and NEX-7 are very close. The slightly brighter exposure on the D600 does appear to make things look sharper, and the fur on Scooby's paw does seem better defined. In both examples, the white text is easily readable but the red text not really. This seems to be an issue of contrast rather than sharpness though, as the white text is smaller in size. I would predict than in better lighting conditions, the red text should be readable too.
The Nikon D600 has the best sharpness and detail, followed very closely by the Sony NEX-7. In good lighting conditions, there'd be very little to separate the two. This is a huge compliment to the NEX-7, as it is a mirrorless camera with an APS-C size sensor, taking on a full frame DSLR. For future comparisons I'll need to find something with more detail to try and challenge these two cameras.
The Pentax Q obviously can't compete, but it shouldn't have to. It's not a lot worse than the two big boys in the first whole scene size shot, and that's really the level of detail you need when posting on Facebook. The Q is extremely tiny in volume, and only 1/4 the weight of the D600, and 1/2 of the NEX-7 (when the NEX-7 is using a 35mm prime, not the currently pictured monster zoom).
Note that this comparison is focused only on resolution and details. There are many other things that define good image quality, such as dynamic range and colour reproduction, which aren't being tested here. I'll consider looking at these in future reviews.
Update: See Shootout - The Sequal for further tests.