Foreword

Good afternoon, Habr!
I am pleased to bring to your attention the promised third part of an article on Samsung's NX-series of cameras. If you have not yet had the opportunity to read the first part (it tells about the NX300 and NX2000 cameras) - you are welcome, you can learn about lenses with a fixed focal length from the past post , and today we will focus more on zooms.

Theory: zoom lens

A lens with a variable focal length, undoubtedly, is the most convenient and versatile solution for a camera: you can vary both the viewing angle and the approximation of the imaged object. This is achieved quite simple way, which is shown in the picture below:
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One of the lenses (in modern solutions is a whole group of elements) shifts relative to the fixed parts of the lens, changing the focal length (and the field of view, respectively, too). You can read about history and general design features on Wikipedia , well, quite specific glasses are waiting for us.

I want to remind you that NX lenses have several abbreviations that show the use of a particular technology in a particular model.

ED (Extra-Low Dispersion) - A lens that contains one (or several) lenses made from materials with ultra-low light dispersion. Reduces the number of chromatic aberrations.

SSA (Super Sonic Actuator) - The lens is equipped with a silent autofocus motor based on an ultrasonic drive. Allows autofocus system to work faster and more accurately.

OIS (Optical Image Stabilization) - Optical Stabilization System. Objective lenses have a special “gimbal” that is controlled by electronics and reduces the effect of shaking on frame quality. Allows you to shoot at a slower shutter speed and / or in difficult conditions.

I, II, III, IV (1, 2, 3, 4) - Roman numerals denote the generation of a subsystem (more is better) or the generation of the lens itself.

Marking the focal length and aperture, I hope, is clear to everyone.

Practice: zoom lenses

The fixes, of course, give an excellent picture and allow you to get excellent shots, but when you go traveling, shoot some event or just go for a walk with a camera, it’s quite difficult to carry around 3-4 lenses for all occasions, and changing the lens itself can cause the frame to "go away". And it is not always possible to change the lens: dust, rain, traffic, shaking - the conditions that impede the process are a million. A good zoom lens is a versatile and very convenient device that allows you to get great shots in a variety of conditions. It used to have problems with the calculation of complex systems - now we have powerful computers, a ready base of hundreds of solutions, proven materials, opportunities that we simply did not have 20-30 years ago and the main thing is the desire to make a convenient and versatile lens. Of course, 18-500 F / 1.2 with a stabilizer at 4 EV-stop and completely from ED elements remains a solution on the verge of science fiction, but we have more realistic lenses - let's talk about them.

20 - 50mm F / 3.5 - 5.6 ED - II

20-50 is a whale lens for the junior division cameras. A good (read - popular) set of focal lengths, a very compact body in a “folded” state, an average aperture and one element with ultra low light dispersion.



Made of plastic, has a manual "fuse", which removes the extra "trunk" in an inactive state. In general, it is characterized by two words: a compact whale. You should not expect extreme quality, but no one demands it from him.

Diaphragm
F3.5-5.6 (minimum - F22), The number of petals: 7, rounded contour

Minimum focal length
0.28m

Maximum magnification
~ 0.22X

Viewing angle
70.2 ° ~ 31.4 °

The number of groups of elements
9 elements in 8 groups, (1 Aspherical lens, 1 Extra-low Dispersion-lens)

Filter diameter
40.5mm

Length x Outside diameter
40mm x 64mm

Weight
119g

There are not so many examples of photos from it, and the glass, in its essence, is a “plug” for the camera. In principle, if you use only the green mode and do not bother with Photoshop, it will completely disappear. To buy this lens separately is a dubious decision: it is better to buy a decent fix. Indicators of sharpness and chromatic aberrations are normal, (especially considering the price of a glass window), vignetting also raises no questions. And distortions ... you cannot get anywhere from them. Fortunately, there is a photoshop, and in most cases very few people worry about distortion, having a lens for ~ $ 190.



Photos taken at 20-50mm are easy to glance, the shots are quite decent:

<spoiler title = "Photo author: www.flickr.com/photos/50231042@N03 ">













The average price of Yandex market: 6 990 rubles .

18 - 55mm F / 3.5 - 5.6 OIS II

Classics of the genre - 18-55 with F / 3.5-5.6 and a stabilizer. Canon, Nikon and Pentax have such a whale lens. The reason for the popularity probably lies in the fact that every manufacturer really has such a lens, and if everyone has one, then why shouldn't we have it?

Samsung's version is not far from its fellows in the quality of the resulting image, since nothing new has been invented here. Frames are better than 20-50, but the lens itself is almost one and a half times larger in physical dimensions: if you have a 20-50 camera, you can somehow attach the camera in your jacket or jacket pocket, then from 18-55 it will have a probability of 146% interfere.



Characteristics are as follows:

Diaphragm
F3.5-5.6 (minimum - F22), The number of petals: 7, rounded contour

Minimum focal length
0.28m

Increase
~ 0.22X

Viewing angle
75.9 ° - 28.7 °

The number of groups of elements
12 elements in 9 groups (1 Aspherical lens)

Filter diameter
58mm

Length x Outside diameter
65.1mm x 63mm

Weight
119g

In general, the whale is like a whale: decent enough staff, but you should not expect anything special. Distortion, resolution, vignetting and “barrel” are direct consequences of price and whale origin, all parameters are normal, especially if you shoot the camera immediately in JPEG: it knows all the frame parameters and will be able to correct all the above optical shortcomings in automatic mode.







Average price on Yandex market: 10,500 rubles .

12-24mm F / 4-5.6

Super wide-angle with zoom function. To be honest, it's not entirely clear why we need such a set of focal lengths, when it can easily be replaced with a much more high-aperture 16mm-fix. I tried to use this lens for quite a long time for its intended purpose: shooting a landscape and / or a cityscape, but there were a lot more decent shots at 10mm Fisheye than at 12-14.



This is due to the low quality of the lens itself: chromatic aberrations along the edges of the frame were 2-3 pixels, the color border, of course, is removed in Photoshop, but these are unnecessary gestures and loss of picture quality. The overall resolution of the lens is small, my specimen also disrupted the coaxiality of the lenses. Maybe I just got a test sample that was heavily battered by the skillful hands of previous reviewers (the glass didn’t look new at all).

The characteristics of the lens are as follows:

Diaphragm
F4-5.6 (minimum - F22), The number of petals: 7, rounded contour

Minimum focal length
0.24m

Maximum magnification
~ 0.14X

Viewing angle
99 ° ~ 60.7 °

The number of groups of elements
10 elements in 8 groups

Filter diameter
58mm

Length x Outside diameter
65.5mm x 63.5mm

Weight
208g

With a weight of almost 210 grams, I would prefer any of the wide-angle fixes. I will not show my terrible frames, because there are suspicions that the copy was so-so, but on the Internet it was shot quite decent photos, although they do not reach the fixes:













However, there is another opinion , and there is a comparison with two fixes, and what to believe is up to you.

Average price on Yandex market: 18 980 rubles . For this money, you can take any two fixed-focal wide-angle (including the Fisheye), and even for tea cookies. So I would choose exactly 10mm + 20mm, and 12-24 would leave until better times (and the second version of the lens itself).

Interlude

There are only two lenses left, but before I go to them, I would like to say a few words about the whales and the wide-angle. Naturally, they look a bit faded against the background of fixes, but two important facts are worth noting. The first - 20-50 and 18-55, most likely, you get along with the camera (20-50 with the NX1000, 1100, 2000, and 18-55 with the NX200, 210, 300, 20) so that anyone can shoot "out of the box ". The second fact - at 12-24 there are a lot of decent reviews on the Internet. And we have two most interesting lenses left - we will discuss them.

18 - 200mm F / 3.5 - 6.3 ED OIS

From a wide angle to the ultrazoom, it is quite fast and with an optical stabilizer, the most versatile lens for traveling. Of course, you have to pay for universality, and not only with a ruble, but also with weight, dimensions, and compromises in picture quality at extreme zoom positions, but there is nothing to be said about here - physics, sir.



The characteristics of the lens are as follows:

Diaphragm
F3.5-5.6 (minimum - F22), The number of petals: 7, rounded contour

Minimum focal length
0.50m

Maximum magnification
~ 0.28X

Viewing angle
75.9 ° - 8.0 °

The number of groups of elements
18 elements in 13 groups, (3 Aspherical lenses, 2 Extra-low Dispersion-lenses)

Filter diameter
67mm

Length x Outside diameter
105.5mm x 72.0mm

Weight
549g

As you can see, the constructive did not save even a second.

Distortion, in general, is typical for lenses of such a construct: here it reaches -4.3% at the “short” end and smoothly reaches 1.3% at 200mm.

Vignetting, respectively, also "floats" depending on the focal length. Darkening of the image at the corners of the frame at the short end is ~ 1 EV, at the long end - 0.5 EV. The indicator is acceptable, and the vignetting correction is not such a big problem: often the camera knows which lens is hooked to it, and either corrects everything itself, referring to the data in the firmware, or writes information to the SRW file so that you can apply autocorrection in a graphic editor.

The resolution of the lens, like all other characteristics, is strongly dependent on the focal length. In the center of the frame, under normal shooting conditions, everything is fine: there is some “softness” of the image along the edges, which, in principle, cannot be avoided with such a spread of focal lengths.

<img src = " www.photozone.de/images/8Reviews/lenses/samsung_18200_3563/mtf.png " />

And of course, frames. It removes this universal lens very well, although it suffers from its versatility:



















At focal lengths from 18 to 50-60mm, everything is great. Then the quality of the picture falls, but I think the percentage of frames at focal lengths greater than 100mm is usually small, so when choosing “remove medium quality photos” or “shoot nothing” - I think many will prefer the first option.

Autofocus works quickly and almost silently, which, in principle, successfully affects the shooting of video and shooting "from the hip", when you need to quickly and without attracting too much attention to get a few shots.

To pay for it according to the Yandex Market will have about 18,990 rubles .

50 - 200mm F / 4 - 5.6 ED OIS II

If you describe the lens in a nutshell: it is simpler, easier, less than 18-200, it does not allow you to shoot near, but it copes with the far end much better (focal lengths from 100 to 200mm).



The characteristics of the lens are as follows:

Diaphragm
F4-5.6 (minimum - F22), The number of petals: 7, rounded contour

Minimum focal length
0.98m

Increase
~ 0.2X

Viewing angle
31.4˚ - 8.0˚

The number of groups of elements
17 elements in 13 groups (2 Extra-low Dispersion-lenses)

Filter diameter
52mm

Length x Outside diameter
100.5mm x 70mm

Weight
407g

High-quality plastic, metal base, internal focusing mechanism (the front lens does not rotate during autofocus operation or zoom movement), excellent build quality and a very pleasant price tag make the 50-200 a very pleasant and affordable TV. Want to shoot at a concert from the back rows? You are welcome! The optical stabilizer allows you to compensate for up to 4EV-stops, and a good weight distribution will allow you to keep the camera on weight for a long time without suffering from hands poured in lead.

The clearest frames, of course, are achieved with the diaphragm covered up to F / 8, and held to F / 11, after which the diffraction limit begins to spoil the picture a bit, however, at the long end to F / 22, the resolution at the edges and in the center remains at a quite acceptable level

At 50mm aperture gradient across the aperture looks like this:

Starting from F / 5.6 and up to F / 8, you get just a sharp-jarring picture of almost the entire field of the frame.

For 100mm, the picture is slightly worse, but still remains within reason:


For 200mm, all the results are even lower, but here mother physics comes into force with its own laws. Want maximum clarity - take a 200mm fix.

Chromatic aberrations are practically absent at 50mm and are on the verge of distinguishable at maximum 200mm focal length.

In the most unfavorable version (an open aperture at a 200mm focal length), vignetting is ~ at 0.5 EV, in all other cases - around 0.2 ~ 0.3 EV.









And now the most delicious: the average price on the Yandex market is only 9,890 rubles . For such a lens - penny. If you already have a 45mm, 18-55 or 20-50, then this is the first candidate for the purchase, if you feel the need for pictures "at a distance."

Zoom lenses, brief summary

In the table below, I collected all the lenses, their pros and cons.

Model	pros	Minuses	Comment
12-24mm	Not bad assembled, allows you to shoot both indoors and outdoors;	Price, variation in build quality, weight, dimensions;	I would prefer 2 fixes instead of this lens. 10mm + 20mm or 10mm + 30mm will give the same scope for creativity.
20-50mm	The cheapest whale. Compact, makes good frames (for its price);	The cheapest whale;	Separately buy is not worth it, and if it comes in the kit, you can use it until you decide what to take for a replacement.
18-55mm	Second whale More, harder, better than 20-50, equipped with a stabilizer;	It is still a whale lens with all the disadvantages that follow;	A good initial glass, but no frills. Buying with 18-200 or 20-50 does not make sense.
50-200mm	Price, weight, picture quality (especially considering the price);	The quality of the image on the long end could be higher;	A very worthy option in a pair of 18-55, 20-50 or fixes, if you really need a focal range from 50 to 100-200mm.
18-200mm	Versatile, allows you to replace a bunch of 18-55 and 50-200.	Expensive, heavy, versatility negatively affects the quality of the picture on the “long” end;	He would have a lower price or better optical quality - would be the golden mean. And so - a little expensive.

In the next post I will talk about the available accessories and buns for NX-cameras or digging in the SRW-files on the subject of opportunities for "pulling" parts - your choice!