Previous page Next page

Timings & File Sizes

The DSLR-A350's overall performance is not nearly as snappy as we've become used to from DSLRs. The delay waiting to review the image (rendered interminable if you're in film strip mode), can easily extend to 3 seconds if you have the gall to use high ISO settings, DRO, RAW+JPEG or anything else that might cause the camera to stop to think.

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 4592 x 3056 JPEG Fine (approx. 3,200 KB per image).

The media used for these tests were:

  • 4 GB SanDisk Extreme Ducati Edition CF card
  • 8 GB Lexar Pro 133x CF card (UDMA)

Media comparison

Action
Time, secs
(4 GB SanDisk)
Time, secs
(8 GB Lexar)
Power Off to On *1 0.9 0.9
Power Off to On (Live view) *1 1.2 1.2
Power Off to Shot 0.7 0.7
Power Off to Shot (Live view) 0.7 0.8
Sleep to On 0.5 0.5
Sleep to On (Live view) 1.2 1.2
Power On to Off *2 2.2 2.2
Record Review RAW *3 1.9 2.3
Record Review JPEG *3 1.8 2.2
Play RAW <0.5 <0.5
Play JPEG <0.3 <0.5
Play Image to Image RAW <0.2 <0.2
Play Image to Image JPEG <0.2 <0.2

*1 Time taken from the power switch being turned to the ON position and 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. These increase substantially, depending on settings.

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 of burst
  • Number of frames - Number of frames in a burst (until buffer full)
  • Buffer full rate - Average frame rate if shutter release held down after burst (buffer full)
  • Write complete - How long after the last shot before the CF compartment light goes out

Burst of JPEG Large/Fine images (Optical viewfinder mode)

Timing
4 GB SanDisk
Extreme IV CF
8 GB Lexar
Pro 133x CF
Frame rate 2.4 fps* 2.4 fps*
Number of frames Unlimited Unlimited
Buffer full rate - -
Write complete - -

Burst of RAW images (Optical viewfinder mode)

Timing
4 GB SanDisk
Extreme IV CF
8 GB Lexar
Pro 133x CF
Frame rate 2.4 fps 2.4 fps
Number of frames 14 10
Buffer full rate ~1.3 fps ~1.3 fps
Write complete 5.5 sec 7.2 sec

Burst of RAW+JPEG Large/Fine images (Optical viewfinder mode)

Timing
8 GB Lexar
Pro 133x CF
Frame rate 1.4 fps (average)
Number of frames 10
Buffer full rate 0.8 fps
Write complete 8.5 sec

Burst of JPEG Large/Fine images (Live view mode)

Timing
8 GB Lexar
Pro 133x CF
Frame rate 1.8 fps
Number of frames Unlimited
Buffer full rate -
Write complete -

Burst of RAW images (Live view mode)

Timing
8 GB Lexar
Pro 133x CF
Frame rate 1.8 fps
Number of frames 11
Buffer full rate 1.2 fps
Write complete 8.0 sec

The biggest story here is not so much the headline frame rate (2.5 frames per second is only a little behind the pace of the A350's peers - 3.0 and 3.5 fps have become standard in this sector), nor Sony's rather conservative estimates of how many RAW files the camera will capture in a burst. Instead, the stand-out figures are those recorded with Live view turned on. Make no mistake, this is a live view camera that happens to have an optical viewfinder, which means the continuous shooting rate most people will experience is a fairly relaxed 1.8 fps.

*Turning dynamic range optimization on slowed the continuous shooting rate from around 2.4 frames per second down to nearer 2.2.

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
(4 GB SanDisk)
Time, secs
(8 GB Lexar)
Approx.
size
4272 x 2848 RAW + JPEG 3.0 4.1 13,500 KB
4272 x 2848 RAW 2.4 3.1 11,500 KB
4272 x 2848 JPEG Fine 2.0 2.6 2,700 KB

As you can see there's quite a large performance differential between the SanDisk Extreme IV Ducati and the Lexar Pro 133x . Further testing produced figures of up to 5 MB/sec for the SanDisk Extreme IV and nearer 4 MB/sec for the Lexar Pro 133x.

USB transfer speed

To test the DSLR-A350's USB transfer speed we transferred approximately 500 MB of images (mixed RAW and JPEG) from a SanDisk Extreme IV Ducati Edition 4 GB CF card.

Method
Transfer rate
SanDisk Extreme USB 2.0 card reader 15.8 MB/sec
Sony DSLR-A350 (PTP device) 1.1 MB/sec
Sony DSLR-A350 (Mass storage device) 6.9 MB/sec

In mass storage mode, the A700 featured the fastest data transfer rate we'd seen at that time. It's fair to say that the A350 isn't built around the same architecture. Its 6.9 MB/sec transfer rate in mass storage mode isn't too shabby (though it's nowhere near the A700's scortching 21.6 MB/sec), but is slow enough to make it worth buying a decent card reader.

PTP mode is just horrendous: it takes nearly 20 seconds to transfer a single RAW + JPEG exposure. It'll take around ten minutes to transfer 36 RAW + JPEG files to your computer and you wouldn't have to wait much longer if you wanted a similarly sized roll of film devloped and printed.

Previous page Next page
49
I own it
1
I want it
54
I had it
Discuss in the forums

Comments