Timings & File Sizes

All in all the DiMAGE 7 is relatively fast, it performed in most areas very similarly to Nikon's Coolpix 995 or Canon's G1. Because of its use of a fairly large buffer the camera is able to return control to the photographer while still writing the last image(s) to the Compact Flash card (except for RAW and TIFF images where the camera blanks the LCD / EVF and you must wait until the whole file is flushed). Playback is also speedy, the D7 appears to implement a thumbnail image in the file header, browsing through images in play mode is virtually instant. The D7 is probably only let down by its occasionally temperamental auto focus system (especially at telephoto focal lengths).

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 2560 x 1920 FINE JPEG image (approx. 2.0 MB per image).

The media used for these tests were:

• 16 MB Lexar Type I Compact Flash card (as supplied in European Kit)
• 320 MB Lexar Pro 12x Type I Compact Flash card
• 1 GB IBM Microdrive Type II Compact Flash card
  

Action	Details	Time, seconds (Supplied CF)	Time, seconds (Lexar 12x CF)	Time, seconds (Microdrive)
Power: Off to Record		3.6	4.0	3.1 / 6.1 *6
Power: Off to Play *1	Accessing	n/a	n/a	3.1
Power: Off to Play *1	Displayed	3.6	3.8	6.4
Power: Record to Off *2		3.4	3.3	3.2
Power: Play to Off		3.2	3.3	3.1
Mode: Record to Play		2.3	2.4	3.5
Mode: Play to Record		1.8	1.8	1.8
Play: Magnify to x2.0		4.1	4.0	4.9
Rec: Thumbnail view 3 x 3		0.8	0.6	0.8

Action	Details	Time, seconds (average)
Auto Focus LAG *3	Full wide angle (28mm equiv.)	1.2
Auto Focus LAG *3	Full telephoto (200mm equiv.)	2.5
Auto Focus LAG *3	Full telephoto Macro (200mm equiv.)	3.7
Shutter Release LAG *4	Using LCD monitor / EVF	0.1
Total LAG *5	Lens @ 50mm equiv.	1.0 - 4.5
Off to Shot Taken	Media: Supplied 16 MB Lexar CF card	5.6
Off to Shot Taken *6	Media: 1 GB IBM Microdrive	8.1
Shot to Shot	Instant playback enabled	2.6
Shot to Shot	Instant playback disabled	2.0

The AF system did feel slower than the timings above reveal, certainly on occasions it was quite fast (with a good contrast target in good light), however there were occasions where it would simply refuse to lock, especially at telephoto focal lengths and with targets which were less than optimum. The D7's AF system hunted more than I've been used to in recent times (digital camera AF systems HAVE got better), indeed sometimes it would hunt even if you had already taken a shot of the same subject. In some situations it would show the white dot indicating a good focus when it was in fact well out of focus.

Continuous modes

The table below shows the results of our continuous shooting test, indicating the actual frame rate along with maximum number of frames and how long you would have to wait after taking the maximum number of frames before you could take another shot.

As we can see the actual frame rate is limited by the speed at which the camera can retrieve the five million pixels from the CCD, the number of frames is limited by the final image size. Frame rates are slightly disappointing, most people would expect at least 2 frames per second of a digital camera at this level and price point. That said you can take nine x 5 megapixel frames at standard JPEG compression in one burst and taken another shot less than 3.5 seconds later.

Continuous mode Flush Timing

The timings above represent the speed of the camera and its internal buffer, however the speed of the Compact Flash card will also have an impact on shooting continuously, it defines how long we must wait before the ENTIRE "burst" of frames are written away to the card (flushed).

Biggest surprise here is the Microdrive which finishes flushing a whole ten seconds before Lexar's Pro 12x Compact Flash card.

File Flush Timing

Timings shown below are the time taken for the camera to process and "flush" the image out to the Compact Flash card, the timer was started as soon as the shutter release was pressed (shutter click was heard) and stopped when activity indicator LED beside the storage compartment went out. This means the timings also include the cameras processing time and as such are more representative of the actual time to "complete the task".

The media used for these tests were:

• 16 MB Lexar Type I Compact Flash card (as supplied in European Kit)
• 320 MB Lexar Pro 12x Type I Compact Flash card
• 1 GB IBM Microdrive Type II Compact Flash card

File Sizes

Here's a comparison of the average byte size of each of different image size / quality combinations.

Battery life

In real life use it became obvious that the DiMAGE 7 is a bit of a power monster. Indeed, in one session it managed to chomp through my favourite set of 1600 mAh GP NiMH's in under an hour (and only 60 shots taken). When handling the camera it's obvious that quite a bit of this is being wasted in the heat generated.

We ran the camera through our new battery life test. This test is designed to be fair and comparative to each camera and battery type:

• Take 4 shots without flash
• Wait 2 minutes (50% of the time powering the camera off)
• Take 1 shot with flash
• Wait 1 minute
• Repeat

All batteries had been fully discharged and recharged before the test and all cameras were reset to their factory default settings. Here are the results:

As you can see in our lab test the DiMAGE 7 managed to flatten a set of four AA 1600 mAh NiMH's in an hour and a quarter (or just an hour and six minutes with a Microdrive). This is a pretty poor performance for a modern day prosumer digital camera, and especially one which requires you carry spare batteries in sets of four. Compare this to the Nikon Coolpix 990 which lasted twice as long on the very same batteries. There's almost no comparison to the Canon PowerShot G1 and both Sony's.

With a 1 GB IBM Microdrive battery life was down to 1 hr 6 mins, 115 shots (approx. 10% less)