I did some tests and thought I would share some of my results on how various settings affect how the buffer will fill and how it clears when writing to the memory card. Together these two man concerns determine how many shots you can take in rapid succession.

There are two things that will affect the number of frames you can take in rapid succession:
1) Camera settings that affect the buffer number (rXX)
2) Card write throughput

Each of these is actually driven by multiple factors.
1) Camera settings

-RAW settings - The best RAW r number I could get was r11
It mattered very little whether or not 12 or 14 bit was selected
or whether lossless was selected. Even RAW + JPEG made an
insignificant impact on the buffer.

-Auto Distortion ON/OFF ON results in a r08 no mater what
other settings are selected! (even for small/basic JPEGs)

-JPEG size/compression
Large/Fine-Normal-Basic = r15, r22, r33
Medium/Fine-Normal-Basic = r20, r33, r41
Small/Fine-Normal-Basic = r33, r58, r99

2) Card write tests
Method -
D7000 Nikkor AF-S 18-105 VR ON Manual 1/200s F/5.6 ISO 800 AF-C
Card used - Transcend SDHC 16Gb Class 6
Set Mode dial to CH.
Take as many shots as required to bring the buffer down to r=0.
Pause shooting until the buffer empties,
Then take another single frame .
Look at the timing of the last frame of the burst to the single frame when the buffer is cleared.

23s - r10 RAW 14BIT Lossless A-Dist-OFF
23s - r08 RAW 14BIT Lossless A-Dist-ON
23s - r11 RAW 14BIT Compressed A-Dist-OFF
20s - r11 RAW 12BIT Compressed A-Dist-OFF
20s - r11 RAW 12BIT Lossless A-Dist-OFF
19s - r08 RAW 12BIT Losseless A-Dist-ON
26s - r10 RAW+FINE L Lossless A-Dist-OFF
26s - r10 RAW+NORMAL L Lossless A-Dist-OFF
22s - r10 RAW+BASIC L Lossless A-Dist-OFF
10s - r15 FINE L A-Dist-OFF
09s - r22 NORMAL L A-Dist-OFF
xxs - r33 BASIC L A-Dist-OFF (Could not run down buffer)
07s - r20 FINE M A-Dist-OFF
xxs - r33 NORMAL M A-Dist-OFF (Could not run down buffer)

EDIT to add****************************************
Different Card- SanDisk Extreme 4Gb 30MB/s Class 10
09s - r10 RAW 14BIT Lossless A-Dist-OFF
***************************************************


As expected, the clearance time seems to be a function of the file size and whether there was a RAW + JPEG shot. The card speed also comes into play here but I only tested one card type. Similar results should be seen even with a faster card but the relative effects should be similar. When I said I could not run down the buffer, this meant that I took many shots and the buffer was emptying but I gave up clicking away to save some shutter activations that would not yield additional information.

If your camera settings are such that you never get a large r number the card speed is almost a trivial discussion as the buffer will fill and slow way down.

With an r08 in the display, I could usually get about 10 shots before the fps dropped as some data is cleared while shooting making room for a couple more frames.

Dean
Phoenix, Arizona USA
Nikonians Team Member
Website: The Splendid Silence of Light

Recent Trips: Grand Canyon 2012 Glen Canyon 2012 West Clear Creek

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