Timings & File Sizes

As you may expect the D2H is a very fast camera, that phrase alone doesn't come close to explaining just how instant the D2H feels. Firstly there's power on which is completely instant, even when the camera switch is turned to the off position the camera is actually in 'standby' with some information (frames remaining / frame number) still displayed on the top control panel. Turn the power switch to the on position and the camera can shoot straight away.

The new AF system is a revelation, it focuses quickly, the additional focus modes and focus areas work well and are easy to navigate, continuous auto focus tracking also proved to work well (as you will see in some of the images in the samples gallery).

The one thing I can't measure but must talk about is shutter release lag which appears to be nonexistent (for all intents and purposes). Having used every digital SLR in the market I can confidently say that none can match the D2H for the instant response you feel and total lack of any lag between the shutter release squeeze and the mirror flipping up. Personally I'd say it "feels" faster than the EOS-1D, without the equipment to test such short delays it'd be hard pressed to back that up with any solid figures. In addition to this is the 'blink like' viewfinder blackout time.

Overall the D2H feels as Nikon intended it, like a very fast film SLR with nothing coming between you and getting the shot you want. No delay on startup, very fast and accurate AF, excellent predictive AF tracking, a huge buffer which in a real situation (and a fast CF card) you'd hardly ever fill, massively fast eight frames per second continuous shooting and a shutter release button which feels as though it's connected directly to your brain.

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 2464 x 1632 Fine JPEG (approx. 2.0 MB per image).

The media used for these tests were:

• 1 GB SanDisk Ultra II Type I Compact Flash card
• 1 GB IBM Microdrive Type II Compact Flash card
• 4 GB Lexar Pro 40x Type II Compact Flash card (FAT32)

Action	Details	Time, seconds (SanDisk)	Time, seconds (Microdrive)	Time, seconds (Lexar Pro)
Power: Off to On		0.0	0.0	0.0
Power: On to Off *1		0.0	0.0	0.0
Record: Review *2	JPEG / RAW	0.9	1.5	0.9
Record: Enter play mode *3	JPEG / RAW	1.1	4.5 / 1.2	1.0
Play: Image to Image *4	JPEG / RAW	0.2	1.5 / 0.2	0.2
Play: Thumbnail view 2 x 2		0.4	1.6	0.4
Play: Thumbnail view 3 x 3		0.5	2.1	0.5
Play: Magnify		0.3	0.3	0.3

Low Light Auto Focus

This test is designed to measure the minimum amount of light under which the camera can still focus. The focus target is our lens distortion test chart (shown here on the right), camera is positioned exactly 2 m (6.6 ft) away.

Light levels are gradually dropped until the camera can no longer focus. Before the shutter release is half pressed the lens is manually focused to the closest subject distance (typically 0.5 m) to "throw the focus out". This test target is the optimum type of subject for most AF systems (as it has a vertical line at its center).

AF assist lamp

The D2H doesn't have a built-in AF assist lamp, however it will use the AF assist lamp of a compatible Nikon Speedlight if enabled. In the results below we were using a Nikon SB-50DX Speedlight for the measurements marked 'AF assist lamp: Yes'.

With the AF assist lamp enabled on the SB-50DX the D2H as expected can focus in complete darkness and does so very quickly, just over a second at either wide angle or telephoto. Without the AF assist lamp the camera still manages to focus in very dim situations, -1.9 EV is 0.7 Lux or 0.06 foot-candle. Interestingly in very dim situations the AF system keeps trying by seeking back and forth in ever shorter steps until it locks. Our telephoto measurement above took about three scans back and forth but the camera still managed to lock.

Continuous shooting mode

All test below carried out with the following settings: Nikon 50 mm F1.4 Lens, Manual Focus, Manual Exposure (ISO 200, 1/800 sec, F4.0).

Testing actual frame rate

First we test the D2H's actual continuous frame rate compared to the selected rate. Note that the CH continuous shooting mode is locked at full speed, 8 frames per second but that you can configure CL to any whole number frame rate between 1 and 7 frames per second (the default for CL is 3 frames per second). As you can see from the table below the D2H proved to be very accurate, shooting at exactly the speed selected (average over a burst of 40 frames).

Smart buffering

The D2H uses a buffering technique I have previously coined 'Smart buffering', the large internal buffer is used for two purposes. Firstly it buffers the data coming straight from the image sensor ('unprocessed data') and secondly it is used to buffer the processed image file before it is written to the CF card.

Approximate image processing sequence:

1. Record data as it comes off the image sensor, unprocessed data (approx. 6.4 MB per shot)
2. Store this unprocessed data in the buffer
3. Take unprocessed data from the buffer, convert to image file format (JPEG, RAW, etc.)
4. Store this processed image file in the buffer ready for writing
5. Write JPEG / RAW image files from buffer to CF card

The important thing to understand here is that steps 3 and 5 are happening in parallel, the image processing engine (step 3) is constantly freeing up buffer space for new shots to be stored. This means that you do not necessarily have to wait for the entire burst of frames to be written to the CF card before there is enough space to take another full burst.

In our tests the results (using a 1 GB SanDisk Ultra II) were:

• 40 x JPEG Fine images, approximately 8.7 seconds later enough buffer space for 40 more
• 25 x RAW images, approximately 14.8 seconds later enough buffer space for 25 more

This means that it takes the D2H approximately 218 ms to process each JPEG image (very fast). You will see from the timing tests below that when shooting in RAW mode the full buffer space is not realized until the last RAW image is written to the CF card, which is curious as compressed .NEF files are smaller than the unprocessed data.

Full burst write time

The media used for these tests were:

• 1 GB SanDisk Ultra II Type I Compact Flash card
• 1 GB IBM Microdrive Type II Compact Flash card
• 4 GB Lexar Pro 40x Type II Compact Flash card (FAT32)

The first timing below is how long before you can take another burst of frames, the second timing is how long it takes to write out the entire burst of shots (from the last shot to the CF compartment light going out). We did note that the D2H wasn't shooting at the full 8 fps rate for the last five frames of a full burst of JPEG images using the IBM Microdrive (spin-up delay causes a bottleneck?).

The D2H dispatches with its images very quickly, it clearly has a significant amount of processing power under the hood as well as a high throughput Compact Flash interface. It's also very important to note how important the right Compact Flash card can be, in this case the 1 GB SanDisk Ultra II proved to be blisteringly quick compared to the rest, with disappointing performance with the 1 GB IBM Microdrive and 4 GB Lexar Pro card. One note we'll put on the Lexar card is that we have yet to find a digital camera which is optimized for these larger cards which require the FAT32 filesystem.

A quick test of a few other cards

The tests below were carried out by timing the CF compartment door lamp (an indication of when the camera is writing to the card) and dividing the total size of the files written in that burst by this timing, thus producing a KB/sec throughput figure.

Burst of 40 JPEG images

Card	Throughput (40 JPEG images)
1 GB SanDisk Ultra II Type I	4,192 KB/sec
512 MB Lexar Pro 24x Type I	2,965 KB/sec
4 GB Lexar Pro 40x Type II	2,619 KB/sec
1 GB IBM Microdrive Type II	1,486 KB/sec
512 MB Simpletech Type I	1,273 KB/sec
1 GB Viking Type I	1,057 KB/sec

Burst of 25 RAW images

Card	Throughput (25 RAW images)
1 GB SanDisk Ultra II Type I	4,489 KB/sec
512 MB Lexar Pro 24x Type I	3,150 KB/sec
4 GB Lexar Pro 40x Type II	3,081 KB/sec
1 GB IBM Microdrive Type II	1,662 KB/sec
512 MB Simpletech Type I	1,262 KB/sec
1 GB Viking Type I	1,155 KB/sec

An absolutely amazing performance from the SanDisk card.

File Write Timing

Timings shown below are the time taken for the camera to process and "flush" the image out to the storage media (the amount of time the CF compartment light is on). This timing would hardly ever impact on your usage of the camera because (a) it's so fast and (b) the D2H continues to process images in the buffer and write data out to the storage media in parallel to you composing (and taking) the next shot.

The media used for these tests were:

• 1 GB SanDisk Ultra II Type I Compact Flash card
• 1 GB IBM Microdrive Type II Compact Flash card
• 4 GB Lexar Pro 40x Type II Compact Flash card (FAT32)

An extremely impressive performance, but expected after the results from our continuous shooting tests. The D2H clearly has a lot of processing power and a very good CF interface to push that much data out to the CF cards so quickly. Once more the SanDisk Ultra II proving to be the fastest card by some margin, just half a second to write a single Fine JPEG image.

Battery life

The new EN-EL4 Lithium-Ion battery has a huge capacity of 1900 mAh at 11.1 V (21.1 Wh) and that means that the D2H just lasts and lasts, in our experience noticeably longer than the D1 series with their larger, heavier NiMH batteries. These two battery life tests are from the Nikon D2H manual (reproduced with permission):

Case 1
At room temperature (20 °C/68 °F), approximately 2900 shots can be taken with a fully-charged (1900 mAh) EN-EL4 battery and an AF-S VR 70–200 mm f/2.8G IF ED lens
(VR off) under the following standard Nikon test conditions: continuous high-speed shooting mode; continuous-servo autofocus; image quality set to JPEG Normal; image size set to Large; shutter speed 1/250s; shutter-release pressed half way for three seconds and focus cycled from infinity to minimum range three times with each shot; after six shots, monitor turned on for five seconds and then turned off; cycle repeated once exposure meters have turned off.

Case 2
At room temperature (20 °C/68 °F), approximately 600 shots can be taken with a fully charged (1900 mAh) EN-EL4 battery and an AF-S VR 24–120 mm f/3.5–5.6G IF ED lens (VR off) under the following standard Nikon test conditions: single-frame shooting mode; single-servo autofocus; image quality set to JPEG Normal; image size set to Large; shutter speed 1/250s; shutter-release pressed half way for six seconds and focus cycled from infinity to minimum range once with each shot; after each shot, monitor turned on for two seconds and then turned off; cycle repeated once exposure meters have turned off.