Canon EOS 50D Review: 13. Timings & Sizes: Digital Photography Review

Timings & File Sizes

The EOS 50D is a good performer in all areas. The camera powers on and takes a first shot almost instantly and the measured values for record review and play don't leave anything to complain about either. The new DIGIC 4 processor is clearly doing a good job shifting the large amounts of data captured by the 15 megapixel sensor through the imaging pipeline. Continuous shooting was exactly as specified although a UDMA card is certainly a sensible investment if you plan to use the function a lot. It helps significantly improve buffer-full frame rates and buffer write times.

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 4752 x 3168 JPEG Fine (approx. 5,100 KB per image).

The media used for these tests were:

2 GB Lexar Pro 133x CF card
4 GB SanDisk Extreme Ducati Edition UDMA CF card

Media comparison

Action	Time, secs (2 GB Lexar)	Time, secs (4 GB SanDisk)
Power Off to On	<0.1	<0.1
Power Off to Shot	0.2	0.2
Sleep to On	<0.1	<0.1
Power On to Off *1	<0.1	<0.1
Record Review RAW *2	0.9	0.9
Record Review JPEG *2	0.8	0.8
Enter Live View	1.2	1.2
Exit Live View	<0.2	<0.2
Play RAW	0.3	0.3
Play JPEG	0.4	0.4
Play Image to Image RAW *3	0.3	0.3
Play Image to Image JPEG *3	0.3	0.3

*1	If the camera decides that an automatic 'sensor cleaning' is required then power-off take around 1.5 seconds.
*2	Time taken from the shutter release being pressed to the review image being displayed on the LCD monitor.
*3	If you turn the Quick Control Dial you can scroll through images at approximately 5 frames per second (a pixelated preview version of the images is shown)

Continuous Drive mode

Continuous drive tests

To test continuous drive mode the camera had the following settings: Manual Focus, ISO 100, Shutter Priority (1/400 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 6.3 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 soon after the burst the buffer has emptied / CF compartment light goes out

Burst of JPEG Large/Fine images

Timing	2 GB Lexar Pro 133x CF	4 GB SanDisk Extreme Ducati CF
Frame rate	6.3 fps	6.3 fps
Number of frames	142	no limit
Buffer full rate	2.9 fps	-
Next burst (buffer 55 indicated)	31.0 sec	-

Burst of RAW images

Timing	2 GB Lexar Pro 133x CF	4 GB SanDisk Extreme Ducati CF
Frame rate	6.3 fps	6.3 fps
Number of frames	16	14 *1
Buffer full rate	0.4 fps	2.0 fps
Next burst (buffer 16 indicated)	42.3 sec	7.5 sec

*1	After 14 frames the camera shot 10 frames in a 1-2-1 pattern at an average of 4.8 fps before it dropped to the buffer full rate of 2.0 fps.

The 50D does exactly what it says on the tin and delivers the advertised 6.3 frames per second. The DIGIC 4 processor is doing an impressive job processing the camera's large image files. If you use continuous shooting a lot it's well worth investing in a fast card. It will significantly reduce buffer write times and increase the frame rates after the buffer has run full.

Please note that in AI Servo AF mode the camera, depending on subject and lighting, might not be able to keep the maximum frame rate.

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 Lexar)	Time, secs (4 GB SanDisk)	Approx. size
4752 x 3168 RAW + JPEG	4.5	1.4	25,700 KB *1
4752 x 3168 RAW	3.8	1.0	20,600 KB
4752 x 3168 JPEG Fine	1.3	0.6	5,100 KB
4752 x 3168 JPEG Std	0.8	0.5	2,800 KB

*1	File size reported here is the size of the RAW and Fine quality JPEG files added together.

As we should expect the EOS 50D delivers very fast throughput, with the best performing card (the SanDisk Ducati Edition) we get 17.9 MB/sec. This combined with a large buffer means that you'll almost never find yourself waiting for images to write to the card (unless perhaps you shoot a burst of RAW+JPEG, pretty unlikely).

USB transfer speed

To test the EOS 50D's USB transfer speed we transferred approximately 300 MB of images (mixed RAW and JPEG) from a SanDisk Ducati Edition 4 GB CF card.

Method	Transfer rate
CardBus PCMCIA adapter	10.5 MB/sec
SanDisk Extreme IV USB 2.0 card reader	13.3 MB/sec
Canon EOS 50D (PTP device)	16.3 MB/sec

The EOS 50D just like the EOS 40D doesn't have a 'mass storage device' option, instead communication is carried out using PTP (via WIA on Windows), that said transfer rates are much better than we have seen before via PTP, up to 16.3 MB/sec (more than twice the EOS 40D). This even beats our usually fastest option - the Sandisk USB 2.0 card reader.

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