Performance

The D300 was a fast camera - its 6 frames-per-second shooting speed not placing it that far behind Nikon's professional level sports camera, the D3. The D300S takes things a step further, promising 7 frames-per-second shooting in JPEG mode (which rises to 8 fps if you use one of the D3 series' EN-EL4a batteries in the MB-10 battery grip). The high speed, UDMA-compatible CF card slot helps, of course so you're better off using that than the SD slot if you're after long, fast sequences of shots. This is a camera that will find itself in the hands of many professionals, as well as keen enthusiasts and those pros familiar with Nikon's D3 series are unlikely to find the transition an uncomfortable one - the D300S offers a similar level of responsiveness.

Timings & File Sizes

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 4288 x 2848 JPEG Fine (approx. 4,600 KB per image).

The media used for these tests was:

• 32 GB SanDisk Extreme Pro CF card

Continuous Drive mode

To test continuous mode the camera had the following settings: Manual Focus, Manual Exposure (1/640 sec, F5.6), ISO 100. Measurements were taken from audio recordings of the tests. Media used were the same as above.

The tests carried out below measured the following results for JPEG and RAW:

• Frame rate - Initial frame rate, this was always 8.0 fps (+/- 0.05 fps)
• Number of frames - Number of frames in a burst (for JPEG there is no limit with a fast card)
• Buffer full rate - Frame rate if shutter release held down after burst (buffer full)
• Write complete - How long after the last shot before the CF lamp goes out

Burst of JPEG Large/Fine images

Burst of RAW images

At 7.1 frames per second the Nikon D300S is one of the quickest APS-C DSLRs on the market. In JPEG format the camera maintains this speed for 100 frames and for 17 frames when shooting RAW. The initial frame rate is still maintained when shooting RAW+JPEG but only for 15 frames. For speed-freaks the frame rate can be pushed to eight frames per second by using the optional Battery Pack MB-D10 and EN-EL4a batteries. For those who are less in a hurry there is also a low-speed continuous mode which can be set at between one and seven frames per second.

USB transfer speed

To test the D300S' USB speed we transferred approximately 500 MB of images (mixed RAW and JPEG) from a SanDisk Extreme Pro CF card (the same card used in the other readers). When you connect the camera to your computer for the first time a driver is installed and it appears as a PTP device on your system. Transfer speed was good but slower than both a good external card reader and the built-in model on our office PCs.

Autofocus speed / accuracy

The D300S has one of the most sophisticated AF systems on the market - not just in terms of the number of AF points (51, 15 of which are of the cross type that are sensitive in both the vertical and horizontal axis), but also in terms of its ability to select the active point and track with a subject.

The result is an AF system that you'll need to learn how to use, rather than one you can just take out of the box and expect to deliver. Which isn't to say it's overly complex - we're not sports photographers (nor do we claim to be), but with a little time spent getting used to its behavior, we were impressed by its ability to return a sequence of in-focus images, even in the hands of an inexperienced shooter. We also found it's a system that will continue to work in surprisingly low light, even if it loses a considerable amount of its impressive daylight speed.

The contrast detect AF in live view and movie mode is a fraction faster than we've seen on most DSLRs up until now, when using the 16-85 VR, at least, but it's still nowhere near the speed of a system designed around its use (such as compact cameras or Panasonic's G series). It's really only of use for stationary subjects but it's nice to have in studio settings.

Battery life

The D300S uses the same EN-EL3e battery as the D300 (and D700), and makes good use of its 12Wh capacity. Users shooting a lot of video or in situations such as weddings where its unthinkable to run out of power might want to have a spare in their pocket for the sake of peace-of-mind but most people will find they can fire away all day without having to think about it. The detailed information the camera gives about the condition and charge (in percent) of the battery should also help avoid any embarrassing inability to perform.