Timings & File Sizes
The *ist DS feels snappy and works well, startup is very respectable at just over a second (faster than several other D-SLR's) and thanks to good buffering and a good CPU the camera never leaves you waiting or feels like it's lagging any operation. Continuous shooting was better than most of the competition, image processing and SD write speeds were also respectable, Kudos Pentax.
Timing Notes: All times calculated as an average
of three operations. Unless otherwise stated all timings were made on
a 6 MP / 
(3008 x 2000) JPEG image (approx. 2,700 KB per image).
The media used for this test were:
- 512 MB Lexar 'Hi-Speed' SD card
- 1 GB SanDisk Extreme III SD card
| Action | Details |
Time,
secs (Lexar 512 MB) |
Time,
secs (SanDisk 1 GB) |
|---|---|---|---|
| Power Off to On *1 | 1.1 | 1.1 | |
| Power On to Off | <0.2 | <0.2 | |
| Record Review *2 | RAW |
1.6 | 1.6 |
| Record Review *2 | JPEG |
1.6 | 1.6 |
| Play | RAW |
0.8 | 0.8 |
| Play | JPEG |
0.8 | 0.8 |
| Play Image to Image | RAW |
0.3 | 0.3 |
| Play Image to Image | JPEG |
0.3 | 0.3 |
| *1 |
This timing was taken from the moment the power switch was turned to on to the moment the camera's AF system started to focus (by holding down the shutter release from power on). |
| *2 | This is the amount of time between pressing the shutter release and the image being displayed on the LCD monitor. |
Continuous Drive mode
To test continuous mode the camera had the following settings: Manual Focus, Manual Exposure (1/400 sec, F5.6), ISO 200. Measurements were taken from audio recordings of the tests.
The tests carried out below measured the following results for JPEG and RAW:
- Frame rate - Initial frame rate, this was always 2.7 fps (+/- 0.05 fps)
- Number of frames - Number of frames in a burst
- Buffer full rate - Frame rate if shutter release held down after burst (buffer full)
- Next full burst - How soon after you can take another full burst (indicator shows 9)
The media used for these tests were:
- 512 MB Lexar 'Hi-Speed' SD card
- 1 GB SanDisk Extreme III SD card
Burst of JPEG Fine images
| Timing | 512 MB Lexar SD |
1 GB SanDisk SD |
|---|---|---|
| Frame rate | 2.7 fps | 2.7 fps |
| Number of frames | 8 | 8 |
| Buffer full rate | 1.2 fps | 1.3 fps |
| Next full burst | 6.5 sec | 5.9 sec |
Burst of RAW images
| Timing | 512 MB Lexar SD |
1 GB SanDisk SD |
|---|---|---|
| Frame rate | 2.7 fps | 2.7 fps |
| Number of frames | 5 | 5 |
| Buffer full rate | 0.3 fps (3.3 sec) | 0.3 fps (3.3 sec) |
| Next full burst | 17.0 sec | 16.0 sec |
Overall a fairly respectable performance for an 'entry level' digital SLR, slightly faster than most of the competition and with a larger buffer the *ist DS can fire off eight shots in quick succession in JPEG mode or five in RAW mode. Kudos Pentax.
File Flush Timing
Timings shown below are the time taken for the camera to process and "flush" the image out to the storage card. Timing was taken from the instant the shutter release was pressed to the time the SD activity indicator beside the SD door went out. The *ist DS will begin writing images as soon as it can and continue to write 'in the background' while you take further shots / change settings. You cannot enter play mode while buffered images are being written to the storage card (the 'egg timer' icon is shown).
The media used for this test were:
- 512 MB Lexar 'Hi-Speed' SD card
- 1 GB SanDisk Extreme III SD card
| Image type | Time, secs (Lexar 512 MB) |
Time, secs (SanDisk 1 GB) |
Approx. size |
|---|---|---|---|
| 3008 x 2000 RAW | 5.1 | 4.9 | 10,300 KB |
| 3008 x 2000 (6 MP) JPEG |
2.3 | 2.3 | 2,200 KB |
| 3008 x 2000 (6 MP) JPEG |
2.2 | 2.0 | 1,300 KB |
| 2400 x 1600 (4 MP) JPEG |
3.0 | 2.8 | 1,600 KB |
| *1 | File size reported here is the size of the RAW and JPEG files added together. |
| *2 | The *ist DS begins writing approximately 0.5 seconds after the shutter release is pressed so you must subtract 0.5 seconds from the above timings to get the actual write time. |
A fairly good performance from the *ist DS, with RAW files being flushed out in around five seconds and around two seconds for a six megapixel high quality JPEG. Good buffering means that the actual processing and writing of images never interrupts shooting (unless you fill the buffer) and the camera works fast enough to feel quite responsive. It's perhaps not just a little amusing to note that this makes the *ist DS about twice as fast as its bigger brother, the *ist D, as far as image processing and writing is concerned.
Card performance: High quality JPEG burst
| Card | Pentax *ist DS , write speed (JPEG files) |
|---|---|
| 512 MB Lexar 'Hi-Speed' SD |  2,416 KB/sec |
| 1 GB SanDisk Extreme III SD | 2,508 KB/sec |
Card performance: RAW burst
| Card | Pentax *ist DS, write speed (RAW files) |
|---|---|
| 512 MB Lexar 'Hi-Speed' SD | 2,997 KB/sec |
| 1 GB SanDisk Extreme III SD | 3,128 KB/sec |
Cardbus 32-bit adapter benchmark (Panasonic SD adapter)
| Card | Cardbus 32-bit Adapter, write speed (JPEG & RAW files) |
|---|---|
| 512 MB Lexar 'Hi-Speed' SD |  5,720 KB/sec |
| 1 GB SanDisk Extreme III SD | 9,735 KB/sec |
The results above were produced by measuring the write time for a burst of shots, this gives a more accurate measurement of actual throughput.
Battery life
The *ist DS can be powered by four normal AA batteries (NiMH rechargeable's recommended) or two CR-V3 Lithium (non-rechargeable). During our review we stuck with two supplied CR-V3's and never needed to replace them. Hence just as with the *ist D I can recommend using CR-V3's on the *ist DS (they're also quite noticeably lighter than four AA's).
