Samsung NV40 Digital Camera Review

The NV40 did very well across our entire testing schedule, particularly in manual noise and automatic white balance tests. The color result was good, but not amazing, and the resolution, low light, video and dynamic range results were all superior to the cameras we used for comparison purposes. However, the time from starting the camera to the first shot wasn't as fast as it could be, and in general the speed of the camera was average.

Color (8.33)
One of the most important features of a camera is how well it captures the color of the world around you, so the sky is the right blue, and the grass comes out that proper shade of green. To test this, we shoot the standardized Gretag Macbeth color chart under very strictly controlled lighting conditions.  The captured image is then run through Imatest, an application designed to analyze a number of image parameters, including comparing known color values to the color of a test photograph. This measures the difference between what the camera captures, and what the actual color is. The image below shows this result, where the outer square is the captured color, the inner square is that color with the luminance value corrected by Imatest, and the small rectangle on the right is the ideal color.

The Imatest software also produces a second graph, which shows the difference between the captured and ideal colors as a vector. The squares represent the ideal value, and the circles what was actually captured, with a longer line equating to less accurate colors.

Short lines equate to good colors

Resolution (12.38)
The megapixel rating is often misunderstood to equal image resolution. Actually, final image resolution depends not just on the image sensor’s megapixels, but the lens quality, digital processing and much more. To assess the true detail-capturing performance of a camera, we shoot an industry-standard resolution chart under specific lighting conditions to create a series of test images, which are then analyzed by Imatest to produce a resolution value measured in line widths per pixel height (lw/ph), which is a count of the number of alternating black and white lines the camera can capture horizontally and vertically.

The NV40 captured an impressive amount of detail

The NV40 produced a top score of a horizontal resolution of 2288 lw/ph horizontal and 2055 lw/ph vertical. This is an impressive result; putting the NV40 well above the cameras we're comparing it with. For a $280 camera, the NV40 produced a clear image, with only minor over-sharpening. This means that your photos will contain a large amount of detail, and allow you to zoom and crop your picture while still retaining image quality.

Noise – Manual ISO (11.17)
When cameras shift to a higher ISO to take photos in low light conditions, noise becomes more apparent. Noise is a staticky effect that forms in an image when high light sensitivity settings are used, and areas of the image can appear mottled. To test the level of noise on the NV40 we used Imatest to analyze images taken for the full range of ISOs. The NV40 goes from ISO 80 to ISO 1600 at full resolution. ISO 3200 is available but only with reduced 3-megapixel image size, which falls outside our test parameters.

Auto Noise (2.29)
The auto noise test is undertaken by setting the camera to Auto ISO and letting it decide what is the best setting to shoot a well-lit scene. Keep in mind that to minimize noise, the camera should try and shoot at the lowest ISO possible. The NV40 settled on ISO 200, even though the scene was bright enough for ISO 100. That said, the overall excellent noise levels with this camera means that even at a slightly higher ISO than absolutely necessary it still manages to score better than many others, especially the Pentax Optio Z10, so when shooting in automatic mode the NV40 will produce an image without much noise.

White Balance (10.88)
A camera's white balance score is a measure of how well it can compensate for the altered hues cast by different light sources. It needs to be able to recognize a white object under the yellow cast of an incandescent bulb or the light of the sun. Users can let the camera adjust for lighting conditions automatically, set it to various presets, take a manual white balance reading by shooting a white card or paper, or, with some cameras, enter the Kelvin value that matches the lighting environment. The NV40 doesn't offer this last option, but has a decent number of white balance settings along with manual setting, which is good to see on a relatively cheap point-and-shoot camera. We test the white balance levels of the camera by shooting under the appropriate light sources with both automatic and preset modes. This result is shown below in an exaggerated form – you will not see discrepancies to this level while actually using the NV40.

Auto White Balance(14.65)
The NV40 has excellent automatic white balancing. The only area with any problem is the flash white balance, as you can see from the images below. The auto fluorescent and tungsten settings were both impressive, capturing a color remarkably close to its actual value. The tungsten result is particularly pleasing, as many cameras have trouble with tungsten lighting, which is the setting that is used for incandescent lights that are found in most homes. These fine results across the board mean that the hue of your image will be very accurate, regardless of lighting conditions. This result easily bettered the comparison cameras: the Pentax Optio Z10, Panasonic Lumix DMC-LZ8, Olympus Stylus 830, even the Canon Powershot SD1100 IS which also did very well in this section.

Exaggerated White Balance Errors

Auto WB - Flash Illumination

Auto WB - Fluorescent Illumination

Auto WB - Daylight illumination

Auto WB - Tungsten illumination

 
Still Life
To allow an easy visual comparison between cameras, we shoot two standard scenes under everyday fluorescent lights: our happily married couple and a still life starring Rosie the Riveter. Each of these images was shot at every available ISO on automatic settings. Click on the images below to view full size versions, but this may take some time as they are large files.

 

ISO 80
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600
Hi ISO (3200)

Low Light (6.39)
We tested the NV40’s low light performance in two stages. First, we shoot the Gretag Macbeth chart at light levels that correspond to commonly occurring brightnesses. 60 lux is about as bright as a room lit by two small lamps, 30 lux corresponds to a room lit by a single 40 watt bulb, 15 lux is the light provided by computer monitor or television screen, and 5 lux equates to a single candle in a dark room. All shots were taken at ISO 400.

Low Light Tests
60 Lux	30 Lux
15 Lux	5 Lux

The NV40 had some trouble in this stage, and the color accuracy dropped noticeably at 30 lux and below. If you're shooting in very dark conditions, you may notice that the color in your shots doesn't come out particularly well. However, in the second half of our low light testing, the NV40 fared much better. This latter test involves taking long exposures, and running the resulting images through Imatest. Normally, we test from one second to 30 seconds, but we were unable to produce reliable results for exposures longer than 10 seconds, given the limited manual controls offered by the NV40. However, at the exposures we did test, the NV40 performed above average with minimal noise and good color accuracy.

Samsung NV40 Low Light Scores

Once again, the NV40 performed well, and was consistently able to capture a wide range of grays. We expect to see a certain amount of loss at the higher ISOs, and while the NV40 is no exception, it did better than most other compact point-and-shoots. Once again, it has managed to outperform our comparison cameras.

This test measure the time from when a full resolution photo is taken until it appears as a preview on the LCD screen. The NV40 averaged a time of 1.78 seconds, which is quite fast. It's not as speedy as the Canon Powershot SD1100 or the Panasonic Lumix DMC-LZ8, but it is faster than the Pentax Optio Z10 and Olympus Stylus 830.

Video Performance (6.58)
The NV40 shoots video at two sizes, 640x480 (VGA) and 320x240, both at either 30 or 15 fps.  It stores the movies in MPEG 4 (.avi) format, which is known for taking up only small amounts of storage space. We tested the NV40 at full resolution and highest frame rate to see just how well it performed.

Bright indoor light – 3000 Lux
We illuminate our test charts to a very bright 3000 lux and stabilize the camera on a tripod to simulate optimal recording conditions. Frames from the resulting video are exported and run through Imatest to judge color accuracy. The NV40 scored slightly above average for this test, but not exceedingly well.

Low light – 30 Lux
Just because the sun goes down doesn’t mean you want to stop recording, so we test the color fidelity at 30 lux too. Most point-and-shoot cameras struggle a bit when it comes to recording videos in the darkness, and there is a noticeable quality drop with the NV40. It’s an average result, similar to what we saw on the Canon SD1100, but better than the Lumix DMC-LZ8.

 

Resolution (3.20)
We also tested the resolution of the captured video from the NV40, which gave an above average performance in this test. It captured 618 lw/ph horizontal and 583 lw/ph vertical, which is better than the Powershot SD1100 IS, Optio Z10 and Stylus 830. It’s not fantastic resolution, but low scores are par for the course in this test, as compact point-and-shoot cameras are simply not on the same level as camcorders.

Samsung NV40 Video Scores

Motion
We took the NV40 into the streets of Boston to shoot fast-moving cars, and see how well the camera captures speeding objects. The results were good, as colors came out bright, and there was minimal blurring and noise, and no stuttering. While a decent result for a compact camera, don’t expect the video to look good on an HDTV, as it’s still quite low resolution.