Samsung NX30 Field Test Part II

Samsung NX30 Field Test Part II

Performance & Action Shooting

By John Shafer | Posted: 07/17/2014

When the Samsung NX30 was first announced, I was really impressed with the performance-related features and specs -- especially the autofocus system and speed. Full HD (1,920 x 1,080 pixel) video at 60 frames per second is pretty cool, too. But since I'm primarily an outdoor action-sports photographer who spends a lot of time way up in the mountains, I'm always interested in small, light cameras that have great action performance. The NX30 can shoot full-resolution raw bursts as fast as nine frames per second. That's fast -- faster than the Canon EOS 7D I've been using for most of my action shooting over the past few years.

The NX30 also has a hybrid autofocus system that combines contrast-detection and phase-detection autofocus for increased accuracy and speed. My contacts at Samsung assured me that the camera's action performance was amazing, and that I would be impressed. I've had a chance to shoot a lot of mountain biking with it now, and I am prepared to pass judgment. Read on to learn how the NX30 performed in my world -- a world dominated my mountain biking and other high-speed activities of doubtful value.

Speed

Burst rate is a pretty straightforward specification -- or so you'd think. Nine frames per second is nine frames per second, right? Yes and no. The Samsung NX30 can absolutely blast away that quickly. (Our Imaging Resource lab testing clocked it in at 8.89 fps in JPEG mode.) However, I discovered it has a limited buffer, and can only take about 12 photos before it has to stop shooting and save all those images to the memory card -- if you're shooting in raw mode, anyway. When I switched to Super Fine JPEG, I was able to shoot 42 continuous images before I hit the buffer limit. [Editor's Note: In our lab testing, our buffer depth test is designed as a worst-case scenario with images that are difficult to compress. For the NX30, we saw a Super Fine JPEG buffer depth of around 21 frames, however John's real world shooting may be more indicative of what the typical buffer performance is like.]

But JPEG is an image quality compromise that doesn't work for me. I want as much data as possible, so I can squeeze every little nuance out of my photos with Lightroom and Photoshop. So if you're a raw shooter like me, and you want something like 18 high-speed frames in a row, it's not going to happen with the NX30. That's one of the differences between a sub-$1,000 camera like the NX30 and $5,000+ professional DSLRs like the Nikon D4S or the Canon EOS-1D X. Those cameras have huge buffers which let you blast away for seconds before the camera has to start saving to the memory card.

I don't want to knock the NX30's speed, though. Nine raw frames in one second is very fast. A few years ago, you would have paid thousands of dollars to get that kind of speed. Honestly, it's faster than I need for most of the action I shoot. For sequences, I'll typically only use every other frame from a burst that fast. However, for really fast action, it is very nice to have a burst rate that quick to ensure you get the crux of the action. The ability to capture photos at nine fps made a big difference for me when I was shooting mountain bikers on really technical terrain, allowing me to pick the most critical moment on a challenging trail feature.

Autofocus Performance

The NX30 features hybrid autofocus, which combines contrast-detection and phase-detection AF systems. The hybrid AF system is very quick and accurate for still subjects. The NX30 has 247 contrast-detection points, and allows you not only to select a focus point nearly anywhere on the sensor, but also to change the size of the AF point area. That makes tricky compositions a lot easier. And the autofocus point selection is really intuitive and convenient, too. You just press the "OK" button to activate the AF point, then you can move it wherever you want with the four-way buttons. You change the size by turning the main control dial behind the shutter release button. Samsung did a great job with the NX30's autofocus point-selection controls.

Phase-detection autofocus used to be available only on digital SLRs, where the AF sensor array is located on the mirror. Phase-detect AF is much better at tracking and capturing moving subjects. That's one of the primary reasons professional sports photographers still use DSLRs. If you're a professional action photographer, autofocus is not something you want to compromise on. Since mirrorless cameras are, um, "mirrorless," there's an obvious technical challenge to overcome if you want them to have action-worthy autofocus performance.

Over the past few years, camera makers have started to embed phase-detect autofocus pixels on imaging sensors, improving continuous autofocus performance in mirrorless cameras, and making continuous AF possible for video. Since I shoot a lot of action, I was very curious about the NX30's hybrid AF system and its continuous autofocus performance.

Although I can certainly get great action photos by planning my shots and pre-focusing, having usable continuous autofocus makes a camera much, much more versatile to me. But so far, I've been disappointed with the continuous autofocus performance of almost every mirrorless camera I've used.* Even with these new hybrid AF systems, I still get better continuous autofocus results from most entry-level DSLRs. I was hoping the NX30 would be an exception to that rule.

[*Of course, I haven't had a chance to use every mirrorless camera on the market. The one I'm currently most interested in as far as autofocus goes is the Sony Alpha A6000. That's because I was very impressed with the continuous AF Performance of the Sony Alpha A7 full-frame mirrorless camera when I tested it last fall.]

Unfortunately, the NX30 falls into the disappointing category when it comes to continuous autofocus performance. I have about twenty years of experience shooting high-speed action with autofocus SLRs, including motorsports, cycling, snow sports, etc. With the DSLRs I usually use, I get consistent in-focus high-speed bursts of subjects accelerating towards me. That was not the case with the NX30, though.

I tried all kinds of variations in focus area, point position and focal length, but no matter what I did, the camera's AF system wasn't able to keep up with even relatively slow-moving mountain bikers -- at least not with the 18-55mm and 55-250mm zoom lenses I had for testing. As a control, I also tried shooting bursts as I walked towards a brick wall in bright sunlight. That's a focusing task I think the camera should handle easily. At walking speeds, I did get better results, especially with the 18-55mm kit lens, but they still weren't good enough for me to risk with serious, irreplaceable photo opportunities.

After a few days of playing with the NX30's continuous AF, I resigned myself to the tried-and-true method of pre-focusing.  In single-shot AF mode with the drive mode set for a machine gun-like fully automatic burst at nine fps, I pre-focused on the bit of trail I wanted in focus, then I signaled my rider and blasted away as they came through the appointed spot. Since it's very difficult to time an action shot like this perfectly (especially when you're shooting wide open and have very shallow depth-of-field), the nine fps high-speed burst made a big difference, ensuring I got the sharpest, most perfectly-timed shot. It's a fool-proof strategy for getting good photos of sports subjects that move on a predictable path. It won't work nearly as well for less predictable sports like soccer, football or basketball, though.

I think the NX30's continuous autofocus is probably okay for photos and videos of people walking around, but that's about it. I would not trust it for any real sports, kids, pets, or any other subject that moves quickly and/or unpredictably. For example, I also tried the NX30's continuous autofocus out on some wild horses I came across in the Nevada desert. I was between them and a water hole, and they kept pacing back and forth, making it hard for me to pre-focus -- so I decided to give the continuous AF a shot. Since their relative distance from me wasn't changing much, I thought it might work. It seemed like it was working when I was shooting, but when I got home and got the photos up on the computer, I found that only a couple were actually sharp. The majority of the good ones were a result of pre-focusing.

The bottom line is that I need consistent, predictable and accurate performance, and the NX30's continuous autofocus did not provide that -- at least not for the mountain biking that I shoot most of the time. I can't afford to gamble with iffy autofocus. To be fair, the NX30's continuous AF was on-par with most mirrorless cameras I've used, and I was still able to get plenty of great action photos using single AF, planning my shots and pre-focusing. For any kind of racing or paid commercial work, though, I'd leave the NX30 at home and bring one of my trustworthy DSLRs.

Image Quality & Action

Most people probably don't realize how critical image quality is to good action photography. Of course, image quality is always important, regardless of your subject. But for sports, where speed is critical, sensor performance becomes even more important. When the minimum required shutter speed is over 1/1,000th of a second, high ISO performance is a requirement, not an option.  

There are five different sensor sizes being used in mirrorless cameras right now, from the 1/2.3-inch point-and-shoot sensor on the earlier Pentax Q-series cameras to the full-frame sensors on Sony's Alpha A7 cameras. Each sensor format has its benefits, but as far as image quality goes, bigger is better. The NX30 uses an APS-C format sensor, the size most-commonly used in entry-level and prosumer DSLRs. It's larger than the sensors in Olympus and Panasonic's Micro Four Thirds cameras, but still strikes a good balance between image quality and camera size.

I was pretty pleased with the NX30's performance at higher sensitivities. I found it usable at up to ISO 3200 equivalent, which meant I was able to use fast, action-freezing shutter speeds almost any time I needed them. For most of my high-speed mountain bike action photos, I used the NX30 in shutter priority mode with the shutter speed set between 1/800th and 1/2,000th of a second, with the ISO sensitivity set to auto. That meant I was usually shooting at ISO 800 or higher.

A few years ago, ISO 800 was as far as I was willing to push an APS-C sensor-based camera. But APS-C sensor performance has improved enough in the past couple of years that I'm now comfortable using auto ISO -- especially in tricky conditions and with cameras I'm not completely used to. The key is setting a sensitivity limit that ensures you get good exposures without your images getting too noisy. I set the NX30's auto sensitivity limit to ISO 3200 and it worked great. The camera's metering system usually selected a sensitivity setting lower than I would have chosen myself, and most of my action photos were at ISO 1600 or lower.

Although I don't think it has the best APS-C sensor I've ever used, the NX30 produces very usable images with good detail and low noise, even when bumped up to ISO 3200. There's even room to push the ISO 3200 images around a bit in post if you shoot RAW and don't crop too much. Above ISO 3200 it gets a bit gritty, though. For most of the outdoor action sports shooting I do here in Utah, ISO 3200 is a perfectly reasonable limit. There's plenty of sun and not many trees, here. However, if I was shooting action in California's redwoods or the British Columbia rainforest, I would have to pan and/or use a flash to get good action photos with the NX30.

A Solid Travel & Adventure Camera Choice

Even though the NX30's continuous autofocus performance didn't live up to the hype, it's still a very good travel and adventure camera. I've been road tripping around Utah and Nevada with it, and I've done a lot of mountain biking with it in my pack. The relatively light, compact body makes it really easy to take everywhere, and I discovered that the build is better than I originally thought. Although it's not weather-sealed like some competitors, underneath the NX30's plastic exterior there's a tough metal chassis. So as long as you don't drop it in a creek, have it out too long in the pouring rain, or drop it on the pavement, it should be able to take plenty of abuse. In fact, my experience has been that most cameras can handle much rougher treatment than people realize. I'm pretty hard on my own gear, and I've had few problems that can be blamed on weather or mishandling.

I've mostly used the NX30 with Samsung's 18-55mm f/3.5-5.6 OIS kit lens and 50-200mm f/4-5.6 ED II OS zoom lenses. With those two lenses I've got a very versatile, compact and relatively lightweight kit that works for nearly everything and easily fits in the hydration pack I use when mountain biking. However, if I owned the NX30, I'd get the Samsung 18-200mm f/3.5-6.3 ED OIS zoom to replace the two lenses I've been using, and I'd also pick up their new 16-50mm f/2-2.8 Premium S OIS zoom -- one of the fastest zoom lenses available for any interchangeable lens camera system. With those two lenses, I'd have a great all-purpose compact camera kit: one super-versatile zoom for all-purpose travel and outdoor shooting, and one fast-aperture professional lens for low light photos, portraits and anything else that requires depth-of-field control and top-shelf optics.

Up next

Stay tuned for the third and final installment of my Samsung NX30 Field Test. I'll wrap things up with some in-depth image quality analysis, discuss some problems I had with the camera, and talk about how the NX30 compares to its nearest rivals.