Evaluation of Pentax Quan Huafu SLR K- 1 In-service Life Series

IT 168 evaluation a long time ago, there were three series of rumors about "life" in the photography circle-

Canon enlargement trick

Understand the overall situation.

Then what will go bankrupt?

However, we have to say that 20 16 is a magical year. We have tested the Canon EOS- 1DX Mark II before, and it turns out that its image quality performance has reached the mainstream level, at least it is not the shortcoming of the whole system. Although there are not many exploding nuclear bombs, compared with the previous image quality, it is not an exaggeration to call it a big move.

The second heavyweight product is the protagonist of today's test-Pentax K- 1.

As for the lifetime of the third protagonist in the Legend series, ...

"Product reward

▼ front

At present, there is only one lens in hand, which is Teng D-FA 24-70 mm f/2.8. The overall collocation is still relatively harmonious. Compared with 5D3/D8 10 SLR, it has a smaller body and is slightly cramped to hold.

▼ back

Back layout. The operating logic of Pentax k- 1 is novel, that is, you can select the parameters you want to adjust through the dial at the top, and then use the right-most impeller to select. I have to say it's interesting, but it's still a bit troublesome to use in practice. Fortunately, the parameters on the turntable have corresponding other setting methods. This turntable is just icing on the cake, so it doesn't matter.

▼ above

Above. The overall shape is still angular. From this point of view, this 24-70 lens is quite big. The shoulder screen is small, but the information displayed on it is very good, without any omission.

In order to realize Wi-Fi and GPS functions, there are several small windows and plastic areas at the top. Non-obsessive compulsive disorder can be ignored.

▼ Flip the screen

"Flip screen, Pentax K- 1 flip screen design is very distinctive. Four kinds of metal structures provide the effect similar to the ball head, which can rotate flexibly and has a good use effect.

The biggest slot point is that the structure is too complicated. Four metal pillars are connected with a plastic turnover mechanism, which makes it feel like it will be folded in a few minutes ... My favorite is the direct turnover structure of Canon 80D/ Nikon D5500, which is simple and easy to use.

Atlas's performance completely lived up to expectations, and the appearance of the whole K- 1 was appreciated by Pentax.

"Image quality test

"Because Pentax K- 1 is equipped with a more magical function-pixel offset resolution, the upper limit of available resolution is greatly improved without changing the total pixel of the sensor.

At the same time, it has the function of "moving body correction" added by Pentax k-3II, and it is also very useful in non-static photography (such as landscape photography). Therefore, this image quality test will be divided into two modes: on/off pixel offset resolution. At the same time, in the next article, I will give you an analysis of the advantages and corresponding limitations of this function.

"Resolution test

Because Pentax's PK bayonet can't be switched to Nikon's port, the original lens D-FA 24-70/2.8 is used in this resolution test, which is not directly compared with the previous test. The main purpose is to compare the difference of image quality under the condition of pixel offset resolution switching. The focal length is set to 50mm and the aperture is f/5.6, and the difference of resolution in the central area is compared.

▼ MTF50 resolution test

"After pixel offset is turned on, the effect is actually not as obvious as expected-only 12.6% improvement.

Converted into pixels, it is equivalent to carrying a sensor with 46 million pixels. In theory, the resolution of four images can be equivalent to 72 million pixels after displacement synthesis. Of course, this may be related to the limitation of lens quality. If you switch to a high-quality fixed-focus lens, it should bring better results.

▼ Real-time shooting

You can still see the difference if you look closely, and the clarity on the right is better. And shooting pure still life will not cause any side effects. As for the more complicated shooting environment, we will analyze it for you later.

"Theoretical dynamic range test

It is also divided into standard mode and pixel offset resolution mode. Because the pixel offset resolution mode adopts the mode of four superimposed images, the noise floor is suppressed to some extent. However, because the four images are staggered by one pixel, the noise floor of the four channels is not necessarily uniform, and the actual effect should not be as good as direct four-stack. Without further ado, let's take a look at the test results:

▼ Pentax K- 1 theoretical dynamic range test

In short, there are actually the following points:

"1, K- 1 is undoubtedly in the first echelon from the standard mode and the dynamic range level of short-time exposure.

—— The dynamic range score of ISO 100 of the uncrowned Nikon D8 10 is 14.36EVs, and K- 1 is slightly different.

"2. Frankly speaking, the dynamic range under long exposure is not enough.

Whether it is low or high. The problem of heat accumulation caused by the five-axis anti-shake design structure suspension sensor can not be solved simply by making a large metal body.

3. The dynamic range level of dynamic range ISO 100 has really set a new record (Nikon D 810 @ ISO 64:14.76 EVS) after turning on the pixel offset resolution. However, the fluctuation range gradually decreases from low to high, which is different from that of Quaternary.

"benchmark ISO tolerance test

Significance of effective pixels: The camera can output the largest size picture on the premise that the image quality can reach the signal-to-noise ratio you set.

The image quality of each SNR is as follows:

▲

Signal-to-noise ratio of reference image -20dB

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Signal-to-noise ratio of reference image -30dB

▲

Reference image signal-to-noise ratio -40dB

In this project, only the image quality in standard mode is tested.

▼ Pentax K- 1 Tolerance Test

The direct conclusion is that there is still a certain gap between Nikon D8 10 and Sony A7R2 without pixel shift.

"High sensitivity test.

Significance of effective pixels: The camera can output the largest size picture on the premise that the image quality can reach the signal-to-noise ratio you set.

▼ Pentax K- 1 High-sensitivity image quality test

The high-quality picture quality is also in line with the average level of this level of models-of course, there is still a certain gap compared with the high-quality speed machines such as A7s, D5, 1DX2.

"Function-related testing

Thanks to the five-axis anti-shake, Pentax K- 1 has also brought us several related "new" functions (the quotation is because these functions have been installed on APS-C fuselage before Pentax, but this is the first time in Quan Huafu).

This time, Pentax K- 1 is directly equipped with a GPS module, and the Bank of China is also equipped with this module, but the GPS position recording function is removed, and celestial tracking can be used normally. I have to say that this practice is really opportunistic. However, due to time, we didn't have a chance to test the celestial tracking function.

The second function is low-pass filtering simulation, which eliminates moire fringes by slight jitter-but after testing, it may be because the high-frequency resolution of the lens is insufficient, and the switching function cannot cause any visible changes. Looking at Pentax's full-length mirror, it seems that no product with high resolution can use this function-it can only be said that it looks beautiful.

"Finally, the protagonist of this chapter today, pixel offset resolution.

This function is also commonly known as "shaking pixels". Here, I found a picture to briefly describe its working principle:

When taking four separate photos, each single point is shifted by 1 pixel, but in fact, two green pixels overlap in this process-so the spatial resolution can't reach the level of 3 pixels, and it can only be doubled (theoretically). However, the color resolution of red/blue can indeed reach four times that of the original pixel.

In fact, it is similar to a plane X3 technology, which realizes full-color sampling at a single point. The output picture size is the same as the original pixel, but the sampling frequency is increased.

There is also a way to "shake", as shown in the above picture. The machines used are Hasselblad H5D and Oba E-M5II. By dithering, using pixel spacing and inserting a new pixel in the gap between each pixel, the size of the taken photo has quadrupled-this quadrupling is a real progress. If the image is reduced to the original pixel level, the image quality is better than the previous plane X3 scheme. But isn't this nonsense? This scheme requires 8 samples to output an image, and the sampling rate is inherently higher than that of the plane X3 scheme. ...

Okay, let's get down to business. Let's take a look at the advantages of this scheme in Pentax's hands:

"The biggest advantage is that it is easy to add the function of' dynamic body correction'.

(By the way, four pixels overlap, so it is easy to detect whether the object is moving. For moving objects, it is good to use single data, while for non-moving objects, multi-Zhang Hecheng is used to improve the resolution. This is a great improvement for the practicability of this function.

"But the biggest problem is that if you record in RAW format, post-editing in ACR can't open this function, so you can only use Pentax's own digital camera utility.

..... and the experience of using this software can be summarized in four words.

"It is extremely difficult to use.

In this software, you can set the pixel offset resolution mode yourself. It is not difficult to see that Pentax saved four original images in the RAW file after turning on the pixel offset mode, and the synthesis of these four images was completed by in-machine/post-software algorithm:

Let's see the actual effect. Many people will ask whether pixel offset resolution and dynamic body correction can be turned on under long exposure. It can be turned on until the exposure time is 30s, but the dynamic volume correction effect under long exposure is not good:

And it seems that the effect of turning off dynamic correction is more psychedelic and the exposure time is longer. ...

As for the normal shutter speed (1/200s), dynamic correction is practical:

Considering that the characteristics of Pentax K- 1 are not so suitable for long-term exposure, you can still turn on this function in the usual scenery shooting-even if there is a problem with the correction of the moving body, Pentax will leave you the corresponding original file and close it in DCU. As for DCU software, it's not easy to use, but it can be output as 16bit Tiff to Ps for post-processing. Actually, it can also be used. ...

By the way, a small operational logic problem, pixel offset resolution and bracketing exposure/continuous shooting cannot be turned on at the same time. Students who expect to get the ultimate image quality in both spatial and frequency domains by superimposing /32-bit HDR+ dithered pixels should pay attention. If you need trouble, you can do it yourself. ...

Speaking of features, I finally want to mention this:

As a legendary lantern factory, how can there be no lights? This small LED provides great convenience when changing lenses at night, which is an itchy demand.

"Test and summary of mechanical properties"

The focusing module of Pentax K- 1 uses 33 points, and the actual coverage is good, without all the points crowded in the middle as expected:

On the whole, the coverage area is close to Nikon D600, and the practicality is still guaranteed.

In terms of mechanical properties, a simple test was carried out with D-FA 24-70/2.8, and the results are as follows:

Focusing speed: Because the self-made focusing speed testing equipment is not compatible with Pentax, it cannot be tested.

"Minimum focus brightness from center to focus: 1.2 1lux.

"The success rate of the center's focus tracking is 85.77%.

"The success rate of edge focus tracking is 78.23%.

Some test results of Canon/Nikon D7200/ Sony A6300 are provided for your reference.

▼ Canon 80D/ Nikon D7200/ Sony A6300 Minimum Focus Brightness Test

▼ Canon 80D/ Nikon D7200/ Sony A6300 Center Point Continuous Focusing Success Rate

"The performance of the whole focusing module is still relatively general. Compared with Canon/Nikon, which has been making independent focusing modules for many years, and Sony, which has made efforts in on-chip PDAF, there is still a certain gap.

"In general, K- 1 can take care of all the requirements of this machine, especially in still life shooting. In this case, the pixel offset resolution function can significantly improve the resolution.

But the biggest problem is that there is no suitable high-resolution lens! The Sigma 50ART and Zeiss Otus55/ 1.4 suitable for still life shooting are not available in Pentax, and Pentax's own digital high-definition head (HD) lacks the new Quan Huafu lens, which really feels very powerful.

As a landscape camera, although the lens quality of D (Teng)-FA (Long)15-30/2.8 is good, the wide angle is ok, and the aperture is large enough, under the current technology, five-axis anti-shake is definitely a big debuff-for landscape shooting-but without five axes, the pixel offset resolution function cannot be realized, so it is suitable for this camera.

People want to stop eating, so they don't need cameras ... sweeping the streets is not bad. If you are not obsessive-compulsive about hard quality, Yincui gorge is also a playable choice. After all, all three of them are of the same focal length 135, and the quality is the first.

Graphic Collection 1. 1.7 million RMB Pentax Quan Huafu SLR K- 1 HD proofs.

(escape)