Samsung NX20: Performance

Performance
Timing is one of the two most important considerations when assessing digital camera performance - the other major criteria is image quality. The NX20 is a first rate general purpose digital camera that will dependably produce excellent still images and HD video clips not only for photography enthusiasts, but also for travelers, casual shooters, and family photographers. The NX20 features a self-cleaning sensor and the automatic dust clearing function is activated when the camera powers up and this slows start-up slightly, however the camera is ready to shoot about 2-3 seconds after it is turned on. Overall, the NX20 seems very quick and Samsung claims the NX20's shutter lag has been reduced to 40 milliseconds, which is very snappy -- more than fast enough to capture the decisive moment in all but the the most extreme shooting scenarios. The NX20 also features a new  electronic first-curtain shutter which allows a maximum shutter speed of 1/8000^th of a second and an 8 fps (at full resolution) burst mode as well as the new "Custom Mode" that allows users to save up to three personalized shooting setups as custom shooting modes. These custom shooting modes can then be recalled via the "C" position on the mode dial.

Shooting Performance
Shutter lag and AF acquisition times in good lighting were never a problem for me -- the NX20 seemed comparable, speedwise, to other mirrorless digicams I've used - a tiny bit slower than most entry-level DSLRs, but that can probably be blamed on its inherently slower contrast detection AF system since most DSLRs feature slightly quicker Phase Detection AF systems. I expected AF acquisition in dim lighting to be noticeably slower than in good light, but I was pleasantly surprised when the NX20 performed much better in low light than I expected, especially given the slow maximum aperture of the kit zoom. 

The NX20 features a TTL Contrast Detection AF system with Center AF, Multi AF, Selective single-point AF, Tracking AF, and Face Detection AF. The NX20's AF system analyzes the scene in front of the lens and then calculates camera-to-subject distance to determine which AF point (in the default multi AF mode) is closest to the primary subject and then locks focus on that AF point. Press the shutter button half-way and the AF marks will turn green (if focus is achieved) or red if the AF system can't lock focus. AF is consistently quick and dependably accurate.

Pop up the NX20's flash and the unit deploys with a confidence inspiring thump. There is also a standard hot shoe for mounting external flash units like Samsung's SEF-42A or SEF220A. The NX20's multi mode pop-up flash provides an acceptable selection of artificial lighting options, including auto, auto & red-eye reduction, fill flash, slow sync, and manual.  Flash output can be adjusted via (+/- 2EV) flash exposure compensation. Based on my very limited flash use, the NX20's flash recycle time is between 3-4 seconds. The NX20's built-in flash has a guide number of 11 at ISO 100, so the range will obviously be fairly short - even when shooting at the kit zoom's f3.5 maximum aperture.

According to Samsung, the NX20 is good for 360 exposures (without flash) on a freshly charged BP1310 rechargeable lithium-ion battery. The battery is charged outside the camera, utilizing the included charger, and requires about three hours to full charge the depleted battery.

The Samsung NX20 saves images and video to SD/SDHC/SDXC memory media.

Lens Performance
When the NX20 is powered up, the zoom extends from the camera body automatically, once you've remembered to make sure the LCD screen is facing out and to remove the included pinch-clip lens cap. When the camera is powered down, the lens retracts into the camera body. Zooming is manual -- like in the old days, so speed is dependent upon the shooter. There is no motor noise which is nice when shooting video. 

The NX20's 18-55 kit zoom was better than I expected it to be and noticeably better than the kit zoom offerings of most of the NX20's competitors. Images were a bit soft in the corners at wide angle, with very slight light falloff and some noticeable barrel distortion. At the telephoto end of the zoom, corner softness had dissipated substantially. Corners were uniformly sharper at the long end of the zoom than they were at the short end. Chromatic aberration (purple fringing) was largely absent at 18mm and, while visible at 55mm, is very well controlled. Current NX20 lens options are adequate, but a bit slim --  consisting of 3 zooms (18-55mm, 20-50mm, and 50-200mm) plus three pancake primes (16mm, 20mm, and 30mm) and a 60mm f/2.8 macro lens. Samsung claims the NX20, "...produces images that rival those of any premium DSLR" - a claim that I won't quibble with.

The NX20's sensor shift image stabilization system reduces blur by rapidly and precisely shifting the 23.5mm x 15.7mm CMOS sensor to compensate for involuntary camera movement. Image stabilization allows users to shoot at shutter speeds up to three f-stops slower than would have been possible otherwise. Image stabilization is also helpful when shooting in dimly lit indoor venues where flash is inappropriate or where flash use would be obvious when viewing the image.

Video Quality
The NX20 records video at 1920x1080p @ 30fps with stereo audio. The zoom can be used during video capture and since the zoom is moved manually no lens motor noise will be recorded. The video clip that accompanies this review was shot in the late afternoon of a cold winter day in an old dimly lit building used for boiling maple sap down to make maple syrup. Given the very dim lighting and zoom extension video quality is impressive.

Image Quality
The NX20's image files and videos are clearly optimized for accurate real world colors and slightly hard contrast.  Images display very good resolution (sharpness) with neutral colors and almost no noise up to ISO 800.  Viewed on my monitor - images from the NX20 look a lot like the ISO 100 Agfa slides I shot while I was living in Germany.

Most consumer digital cameras boost color saturation - reds are a bit too warm, blues are noticeably brighter than they are in real life and greens/yellows are overly vibrant. Veteran shooters call this "wet paint color" because casual shooters like bright bold colors. The NX20's images are highly-detailed and surprisingly sharp with highly accurate hues and good contrast.  

The NX20 provides users with a very good selection of white balance options, including auto WB, daylight, cloudy, fluorescent 1, fluorescent 2, tungsten, and custom (manual WB). The NX20's auto WB system does a very good job across the board, even under incandescent and fluorescent lighting.

The NX20 provides a very impressive range of sensitivity options, including auto and user-set options for ISO 100 to ISO 12800. ISO 100 and ISO 200 images are essentially indistinguishable. Both settings show neutral colors, slightly hard native contrast and virtually no noise. ISO 400 images were also very good, but with a tiny bit less pop. At the ISO 800 setting, noise levels are noticeably higher and there's a perceptible loss of fine detail. 

Our sample images show, however, that highlights can be easily blown out and fine details have the ability to get lost in the shadows.

Additional Sample Images