Quality & Size Options

There are three JPEG compression settings, fine (roughly 1:4 compression), normal (roughly 1:8) and basic (roughly 1:16). In addition to choosing a compression format, you can select a compression strategy, between size priority (producing relatively uniform file sizes) and optimal quality, with more file size variation.

Unlike most cameras, the D300S supports uncompressed storage in two formats, TIFF and NEF (Nikon’s RAW image format). NEF files can be saved entirely uncompressed, or in one of two compressed formats. Lossless compression processes the file mathematically for a 20-40% file size reduction with no loss of image quality. Compressed NEF cuts files size down by 40-55% with minimal effect on image quality. In addition, the user can choose 12-bit or 14-bit NEF recording: the 14-bit files are about 1.3 times larger but incorporate more precise color data.

When shooting RAW+JPEG, any of the three JPEG compression ratios can be used. An interesting option that takes advantage of the dual memory slots is the ability to save the RAW images onto one card and the JPEG version onto the other.

The D300S supports three image size settings:

Dynamic Range (7.34)

The D300S starts out with a strong 7.35-stop dynamic range at ISO 200, but it falls off fairly quickly at ISO settings above 400, resulting in a mediocre overall score in this section. At ISO 800, for example, the D300S is down to a dynamic range of 5.25, where the Canon 7D still offers 6.68 stops.

We test dynamic range by shooting a 20-section Kodak stepchart at a constant light level, across the range of standard ISO settings. The individual test shots are analyzed using Imatest software, and the results are then combined to produce an overall performance profile.

As shown in the chart below, where wider bars indicate a greater ability to maintain detail in both light and dark areas, the Nikon D300S performs well at ISO 200 and 400, but dynamic range drops off significantly from that point on. More on how we test dynamic range.

Looking at the dynamic range performance for each of our comparison cameras when shooting at ISO 200, all but the Micro Four Thirds-based Panasonic are roughly equivalent, with the Canon 7D offering a slightly more generous range.

When the full ISO range is taken into account, the Nikon D300S trails the other tested cameras in dynamic range, while the Canon 7D shows considerable strength.

Image Stabilization (9.77)

The VR lens offered a substantial improvement in a key category of our image stabilization testing: compensating for the kind of typical low-intensity horizontal movement encountered in handheld shooting, and this effect holds true at every tested shutter speed. When the camera was moved vertically, though, the VR effect was negligible, and when the level of shake was intense, the system produced lower-resolution results at faster shutter speeds.

We test image stabilization by mounting the camera in a custom computer-controlled rig that produces consistent movement patterns, and shoot at two different levels of shake, with and without the image stabilization system. By comparing the two sets of results, we can analyze the effect of IS on image resolution. More on how we test image stabilization.

At the low shake setting, the VR lens offered a major sharpness boost when the camera was moving horizontally, though it proved ineffective against vertical shake.

Here again, vertical shake was basically unaffected by the VR system. Against aggressive horizontal shake, though, the camera did better with the VR system turned off at shutter speeds above 1/60 second.

The Canon 7D produced a smaller improvement against low-intensity horizontal shake than the Nikon D300S, but the IS system was more effective overall in providing some enhancement under all shooting conditions, producing a higher score.

The following same-size crops offer a visual indication of the variation when found when shooting across the range of shutter speeds, with the camera moving horizontally.

Image Stabilization Comparison Table			Expand
	Low Shake IS Off	Low Shake IS On	High Shake IS Off	High Shake IS On
1/500
1/250
1/125
1/60
1/30
1/15
1/8