Here are some measurements performed over 3 different sessions:
MF lens (to reduce focusing speed variations)
Continuous Shooting (Hi) operation
Transcend 8GB Class 10 class (unless noted)
PEF format (I don't shoot JPEG)
SR & levelling off
Firmware: 1.11
Speed can vary both in a burst (unexpected hesitation) and between bursts at the same settings. I've used a digital sound recorder to count the shots before large delays occur. I've also measured the time from the first to the last peak in this group to determine the average shot time & rate. (Using peaks means you don't have to worry about the problem of determining the exact start of a shot). All measurements were taken with both the camera and sound recorder on tripods, with the sound recorder situated on the left side of the camera (the right side has the battery bulge that probably shields the sound more) and a distance of 0.5m from the microphone to the lens mount centre.
Normally you'd be using large bursts when shooting sports/action. In the bright daytime, that's typically at a max. shutter speed of about 1/1000s.
1/1000s
25 shots were taken at a rate of 164 ms/shot (6.1 shots/s)
26th: 228 ms
27th: 1003 ms
1/100s
24 shots: 173ms/shot (5.8 shots/s)
25th: 991ms
1/4000s
26 shots: 164 ms/s (6.1 shots/s)
27th: 930 ms
I then switched to a 8GB Apacer Class 6 Card. Here is a comparison of the Write & Read speed as measured with a 7000 MB test file:
Transcend 8GB Class 10 - Write: 17.1 MB/s, Read: 21.4 MB/s
Apacer 8GB Class 6 - Write 8.5 MB/s, Read: 16.5 MB/s
There was no difference in the shooting rate at 1/1000s, but the effective burst length was reduced to about 24 shots. (I didn't look at recovery speed after the shot buffer was full as this was inconsistent.)
So, with PEF, the typical max. burst length at 1/1000s should be about 24-26 shots.
I then looked the typical & maximum acoustic peaks & RMS averages of these bursts. These are not A-weighted and this is a calibrated sound level meter, so use it as an indication of relative sound level in dB:
| 1/100s | 1/1000s | 1/4000s |
Max. Peak | -7.18 | -7.1 | -2.44 |
Typ. Peak | -9 | -9 | -3.5 |
Avg RMS | -29.17 | -29.13 | -27.6 |
You can see that using a high shutter speed increases the average sound level of the total burst by about 1.5 dB, but the typical peaks in the burst are 5.5 dB higher & the max. peak that occurred is about 4.6 dB higher.
Finally, a comparison of the K-5 & K20D shutter sound levels. Since there is some variation over the sound level of individual actuations, I looked at a number of these measurements. I think the typical difference is that the K-5 is about 3.2-3.5 dB quieter, with a different shutter noise frequency distribution (bassier & a little more midrange and less high frequencies). I'm not sure what the difference would be after A-weighting.
Survey of K-5 Continuous Shooting Speed This table will be updated as submissions arrive
Raw, AF-C, Focus-Priority
User | Date of Manufacture (YMD) | Prod. ID | F/W | FPS |
dosdan | 2011-03-15 | 2 | 1.11 | 6.1 |
RonHendriks1966 | 2011-01-21 | | 1.11 | 6.8 |
Dan.
Last edited by dosdan; 10-22-2011 at 02:53 AM.