Timing & Performance

Sigma claims the DP1 is a DSLR substitute in a compact package. While this might perhaps be true in the image quality department it's certainly not in terms of speed. To be frank, the DP1 feels mostly fairly sluggish and sometimes even painfully slow, most budget compacts will give it a run for its money.

The Sigma takes almost four seconds to get ready for shooting and it only gets worse form there. The autofocus is very slow and completely gives up in dim conditions. Typically a compact camera's AF will slow down in low light but most of them will lock the focus eventually. Unfortunately that's not true for the DP1. Once you've focused you will experience the rather unimpressive shutter lag and after you've pressed the shutter button you can decide how to entertain yourself while the camera is writing its data to the SD card. Should you be thinking about using the built-in flash, select your shots carefully, it takes ages to recycle (which means the DP1 certainly is not the ideal party snapshot camera). All in all a rather lengthy experience.

If things need to work quickly in your world the DP1 definitely is not for you. If you carefully set up every shot and aren't too much worried about some waiting time in between shots you might be able to live with the DP1's slow speed of operation.

Timing Notes

All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 2640 x 2592 Fine JPEG image (approx. 2,230 KB per image). The media used for these tests was a 4.0 GB Sandisk Extreme III card.

Action	Details	Time, secs
Power: Off to Record		3.6
Power: Off to Play	Image displayed	4.2
Power: Record to Off	All activity ceased	1.8
Power: Play to Off	Lens extended	1.8
Power: Play to Off	Lens already retracted	0.1
Record Review RAW	Image displayed	2.8
Record Review JPEG	Image displayed	2.4
Mode: Play to Record	Lens already extended	1.4
Mode: Record to Play	Lens already extended	0.4
Play: Magnify	To full magnification (16x)	1.6
Play: Image to Image RAW	Time to display each saved image	0.2
Play: Image to Image JPEG	Time to display each saved image	0.2
Play: Thumbnail view	3 x 3 thumbnails	0.4
Half-press Lag (Focus time)		1.2*1
Pre-focus Lag (S1>S2)	LCD live view	~0.2
Full-press Lag (0->S2)	LCD live view	1.6
Off to Shot Taken	LCD live view	5.6
Shot to Shot RAW	Flash off	~4.5
Shot to Shot JPEG	Flash off	~3.6
Shot to Shot RAW	Flash on ( red eye reduction on / off)	~6.2 / ~5.5
Shot to Shot JPEG	Flash on ( red eye reduction on / off)	~5.6 / ~3.9

The lab tests confirm what we experienced while out and about with the DP1. The camera can really test your patience, especially when shooting in RAW. If your photographic style requires speedy operation go away now and look somewhere else.

Lag Timing Definitions

Half-press Lag (0->S1) Many digital camera users prime the AF and AE systems on their camera by half-pressing the shutter release. This is the amount of time between a half-press of the shutter release and the camera indicating an auto focus & auto exposure lock on the LCD monitor / viewfinder (ready to shoot).	(Prime AF/AE)
Half to Full-press Lag (S1->S2) The amount of time it takes from a full depression of the shutter release button (assuming you have already primed the camera with a half-press) to the image being taken.	(Take shot, AF/AE primed)
Full-press Lag (0->S2) The amount of time it takes from a full depression of the shutter release button (without performing a half-press of the shutter release beforehand) to the image being taken. This is more representative of the use of the camera in a spur of the moment 'point and shoot' situation.	(Take shot, AF/AE not primed)

Continuous mode

The tables below show 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. The media used for these tests was a 4GB Sandisk Extreme III SD Card. Shutter speed was kept above 1/200 sec during these tests.

Continuous drive mode

The DP1 only has one continuous shooting mode. At the highest image quality it gives you three frames per second which is not bad at all for a compact camera. However, most DSLRs are (significantly) quicker and the usefulness of the DP1's continuous mode is seriously flawed by the fact that you can only shoot three frames in one burst. After that the buffer is full and the camera takes its time (and a lot of it) to clear it and get ready for the next burst. Depending on your setting it can take between 9 and 13.5 sec to clear the buffer. This feels like an eternity if you're desperately waiting to take your next shot.

When shooting at lower image quality the frame rates and buffer clearance times get marginally faster but overall the settings you choose have hardly any impact on the DP1's continuous shooting performance. Only the buffer takes noticeably longer to clear when shooting RAW.

File Write / Display and Sizes

Timings shown below are the time taken for the camera to process and "flush" the image out to the storage card, the timer was started as soon as the shutter release was pressed and stopped when the activity indicator went out. This means the timings also include the camera's processing time and as such are more representative of the actual time to "complete the task". The media used for these tests was a 4GB Sandisk Extreme III SD card.

The DP1's write performance is unimpressive to say the least. When shooting RAW the rather large files are written on the card at a rate of approximately 1.75MB/sec. This is not exactly fast and so it takes over 7 seconds before you can take the next image. When shooting in JPEG this decreases to about 4.4 seconds. Considering that the DP1's JPEG files are considerably smaller than their RAW counterparts a large proportion of this time must be taken up by image processing rather than storing.