Timings & File Sizes

The DSLR-A700's overall performance was extremely good, compared to other similar level digital SLRs the only noteworthy difference may be the subtle one second startup time (although off to shot is just 0.7 seconds, nothing which would ever get in the way). In our continuous shooting test the A700 proved to have a good buffer and fast processor and was limited only by the performance of the storage card, we got some amazing figures using a SanDisk Ultra IV CF card but had some strangely lacking performance from the Lexar 133x CF card (although a Lexar 300x CF was ok). The A700 also produced the highest USB transfer speed we've seen to date.

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 3888 x 2592 JPEG Fine (approx. 3,200 KB per image).

The media used for these tests were:

  • 2 GB SanDisk Extreme IV CF card
  • 2 GB Lexar Pro 133x CF card
  • 16 GB SanDisk Extreme III CF card

Media comparison

Action
Time, secs
(2 GB SanDisk)
Time, secs
(2 GB Lexar)
Time, secs
(16 GB SanDisk)
Power Off to On *1 1.0 1.0 1.0
Power Off to Shot 0.7 0.7 0.7
Sleep to On <0.1 <0.1 <0.1
Power On to Off *2 1.7 1.7 1.6
Record Review RAW *3 1.0 1.1 1.3
Record Review JPEG *3 1.0 1.0 1.0
Play RAW <0.5 <0.5 <0.5
Play JPEG <0.5 <0.5 <0.5
Play Image to Image RAW <0.2 <0.2 <0.2
Play Image to Image JPEG <0.2 <0.2 <0.2

*1 Time taken from the power switch being turned to the ON position and the control panel display appearing on the main LCD.
*2 Time taken for the camera to completely power down, it first carries out a 'sensor shake' clean and then continues to access the storage card for just over a second.
*3 Time taken from the shutter release being pressed to the review image being displayed on the LCD monitor.

Continuous Drive mode

To test continuous drive mode the camera had the following settings: Manual Focus, ISO 200, Shutter Priority (1/2000 sec). 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 4.9 fps (+/- 0.01 fps)
  • Number of frames - Number of frames in a burst (until buffer full)
  • Buffer full rate - Frame rate if shutter release held down after burst (buffer full)
  • Next burst - How long after the last shot the camera indicates buffer space '9'
  • Write complete - How long after the last shot before the CF compartment light goes out

Burst of JPEG Large/Fine images

Timing
2 GB SanDisk
Extreme IV CF
2 GB Lexar
Pro 133x CF
16 GB SanDisk
Extreme III CF
Frame rate 4.9 fps 4.9 fps 4.9 fps
Number of frames Unlimited 183 103
Buffer full rate - n/a (uneven) n/a (uneven)
Next burst (buffer 9 indicated) - 5.7 sec 10.0 sec
Write complete - 20.2 sec 34.0 sec

Burst of JPEG Large/X.Fine images

Timing
2 GB SanDisk
Extreme IV CF
2 GB Lexar
Pro 133x CF
16 GB SanDisk
Extreme III CF
Frame rate 4.9 fps 4.9 fps 4.9 fps
Number of frames 178 40 38
Buffer full rate n/a (uneven) n/a (uneven) n/a (uneven)
Next burst (buffer 9 indicated) - 12.0 sec 13.1 sec
Write complete 3.2 sec 22.1 sec 24.5 sec

Burst of cRAW images

Timing
2 GB SanDisk
Extreme IV CF
2 GB Lexar
Pro 133x CF
16 GB SanDisk
Extreme III CF
Frame rate 4.9 fps 4.9 fps 4.9 fps
Number of frames 26 14 14
Buffer full rate 3.1 fps 0.7 fps 0.8 fps
Next burst (buffer 9 indicated) 3.4 sec 15.0 sec 12.9 sec
Write complete 4.5 sec 19.6 sec 17.0 sec

Burst of RAW images

Timing
2 GB SanDisk
Extreme IV CF
2 GB Lexar
Pro 133x CF
16 GB SanDisk
Extreme III CF
Frame rate 4.9 fps 4.9 fps 4.9 fps
Number of frames 20 13 14
Buffer full rate 2.1 fps 0.5 fps 0.6 fps
Next burst (buffer 9 indicated) 4.9 sec 22.0 sec 17.6 sec
Write complete 6.5 sec 28.5 sec 22.8 sec

The specified shooting speed of a full five frames per second wasn't quite achievable although I don't think anyone is going to miss the fractional 0.1 fps difference. Overall an impressive performance, especially using the SanDisk Extreme IV card which provided unlimited shooting in 'JPEG Fine' mode and almost 180 frames in 'JPEG X.Fine', the Lexar card performed less well (see below for more). While not aimed at sports photographers the A700 can still fire quickly enough and for long enough to be used for most purposes.

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 storage card activity lamp beside the compartment door went out. Media used were the same as above.

Image type
Time, secs
(2 GB SanDisk)
Time, secs
(2 GB Lexar)
Time, secs
(16 GB SanDisk)
Approx.
size
4272 x 2848 RAW + JPEG 1.5 3.7 3.4 22,700 KB
4272 x 2848 cRAW + JPEG 1.4 3.0 2.9 16,700 KB
4272 x 2848 RAW 1.2 3.0 2.6 18,600 KB
4272 x 2848 cRAW 1.1 2.4 2.2 12,600 KB
4272 x 2848 JPEG X.Fine 1.1 2.0 1.9 9,100 KB
4272 x 2848 JPEG Fine 1.0 1.4 1.6 4,100 KB

As you can see there's quite a large performance differential between the SanDisk Extreme IV and the Lexar Pro 133x . Further testing produced figures of 34 MB/sec for the SanDisk Extreme IV and just 8 MB/sec for the Lexar Pro 133x. We also tested an 8 GB Lexar Pro 300x (UDMA) CF card which produced the same 34 MB/sec performance as the SanDisk IV (so the 'problem' appears to be only with Lexar Pro 133x cards).

USB transfer speed

To test the DSLR-A700's USB transfer speed we transferred approximately 320 MB of images (mixed RAW and JPEG) from a SanDisk Extreme IV 2 GB CF card.

Method
Transfer rate
CardBus PCMCIA adapter 10.5 MB/sec
Sony DSLR-A700 (PTP device) 11.8 MB/sec
SanDisk Extreme IV USB 2.0 card reader 13.3 MB/sec
Sony DSLR-A700 (Mass storage device) 21.6 MB/sec

The DSLR-A700 in 'Mass storage device' mode delivered the fastest USB 2.0 transfer times of any camera to date, a mighty impressive 21.6 MB/sec means that which means two gigabytes of images would take just over ninety seconds to transfer. Kudos Sony.