With constant motion infront of the camera...
Here is a sample from a FTP server log file...
(modified a bit to get rid of unnecessary info)
Thu Jul 19 14:21:31 /cam/20120719/15/20120719_151940D.jpg
Thu Jul 19 14:21:31 /cam/20120719/15/20120719_151941D.jpg
Thu Jul 19 14:21:31 /cam/20120719/15/20120719_151942D.jpg
Thu Jul 19 14:21:31 /cam/20120719/15/20120719_151943D.jpg
Thu Jul 19 14:21:31 /cam/20120719/15/20120719_151944D.jpg
Thu Jul 19 14:21:31 /cam/20120719/15/20120719_151945D.jpg
Thu Jul 19 14:21:45 /cam/20120719/15/20120719_151954D.jpg
Thu Jul 19 14:21:45 /cam/20120719/15/20120719_151955D.jpg
Thu Jul 19 14:21:45 /cam/20120719/15/20120719_151956D.jpg
Thu Jul 19 14:21:45 /cam/20120719/15/20120719_151957D.jpg
Thu Jul 19 14:21:45 /cam/20120719/15/20120719_151958D.jpg
Thu Jul 19 14:21:45 /cam/20120719/15/20120719_151959D.jpg
Thu Jul 19 14:22:00 /cam/20120719/15/20120719_152010D.jpg
Thu Jul 19 14:22:01 /cam/20120719/15/20120719_152011D.jpg
Thu Jul 19 14:22:01 /cam/20120719/15/20120719_152012D.jpg
Thu Jul 19 14:22:01 /cam/20120719/15/20120719_152013D.jpg
Thu Jul 19 14:22:01 /cam/20120719/15/20120719_152014D.jpg
Thu Jul 19 14:22:01 /cam/20120719/15/20120719_152015D.jpg
Thu Jul 19 14:22:15 /cam/20120719/15/20120719_152024D.jpg
Thu Jul 19 14:22:15 /cam/20120719/15/20120719_152025D.jpg
Thu Jul 19 14:22:15 /cam/20120719/15/20120719_152026D.jpg
Thu Jul 19 14:22:15 /cam/20120719/15/20120719_152027D.jpg
Thu Jul 19 14:22:15 /cam/20120719/15/20120719_152028D.jpg
Thu Jul 19 14:22:15 /cam/20120719/15/20120719_152029D.jpg
You can clearly see the 10 second gaps in the images time stamps.
We are getting 6 images, then there is a pause for 10 seconds before the next 6 images.
(This 10 seconds is the "Send next FTP after X seconds") setting.
It would be ok to ftp the images every X seconds, but images should be captured constantly.
Hope that makes sense.
PS: Willing to test/experiment with any beta firmware for this feature.