Originally posted by opiedog my kx slows down in FPS during AFC mode and i believe this is also true w/ the K7
There are two ways to read your question:
1. Your camera slows down during continous shooting.
This is due to limited buffer sizes and as soon as the buffer is full (a few shots only for the K-x) the camera slows down to a speed as defined by your SD card.
A crazy feature is that the K-7 can actually maintain
FULL 5.2fps for 14.6MP images and an
unlimited amount of time. Just make sure everything is on manual, JPG compression is high (1 star) and the SD card is fast (Sandisk Extreme III).
2. Your camera's framerate in AF.C is lower than in AF.S.
Well, 5.2fps are 192ms per shot and the camera needs about 0.14s to refocus between shots (YMMV). Add the 140ms and you end up with 332ms per shot or 3.0fps. That's normal. The 0.14s are no constant though. On the K-7, I've seen slightly better and significantly worse, depending on the subject and uniformity of motion. Eventually, the K-7 will give up on refocus and just fire. But it may only be after twice the time (0.3s) making it slow down to 2 fps and delivering out of focus shots. However, that's normal procedure again. Most AF.C implementations give up quicker though.
Some cameras (with higher fps) have a faster mirror too. The K-7 mirror though is dampened and swings about 50ms when returning down. This makes it loose about 30ms compared to a harder mirror slap.